Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/27/13
AREA FORECAST DISCUSSION...UPDATE
NWS TUCSON AZ
955 AM MST THU JUL 25 2013
.SYNOPSIS...A DISTURBANCE ALOFT ACROSS THE AREA WILL ENHANCE
THUNDERSTORM COVERAGE AND INTENSITY ACROSS MOST OF THE AREA TODAY.
SOME STORMS WILL GENERATE HEAVY RAINFALL. OTHERWISE...PLENTY OF
MOISTURE ACROSS THE REGION TO PROVIDE A CHANCE OF MAINLY AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND. A DECREASE
IN MOISTURE MAY LEAD TO LESS THUNDERSTORM ACTIVITY EARLY NEXT WEEK.
&&
.UPDATE...HAVE GONE AHEAD AND ISSUED A FLASH FLOOD WATCH FOR ALL OF
SOUTHEAST ARIZONA EXCEPT WESTERN PIMA COUNTY. LATEST VIS SATELLITE
SHOWING A GOOD AMOUNT OF CLEARING WITH THE EXCEPTION OF SOUTHERN
GRAHAM AND NORTHERN COCHISE COUNTY. ALREADY SEEING GOOD CU BUILDUPS
ON AREA MOUNTAINS AS WELL. CONFIDENCE IS HIGH THAT THERE WILL BE
SHOWERS AND THUNDERSTORMS WITH HEAVY RAINFALL AND THINK THE CENTRAL
CWA FROM SANTA CRUZ COUNTY NORTHWARD INTO EASTERN PINAL COUNTY HAS
THE HIGHEST THREAT INITIALLY BUT CONFIDENCE IN EXACT LOCATIONS IS A
BIT LOWER.
.DISCUSSION...THE 12Z KTWC SOUNDING IS DEPICTING A VERY MOIST AND
UNSTABLE ATMOSPHERE. PWAT OF 1.96" IS IN THE 99TH PERCENTILE AND
ABOUT 160 PERCENT OF NORMAL FOR THIS TIME OF YEAR. MEANWHILE...THERE
IS CONSIDERABLY MORE MID LEVEL COOLING COMPARED TO 24 HOURS AGO WITH
THE STUBBORN INVERSION AT ABOUT 500 MB GONE. MODIFIED SOUNDING WITH
T=95 AND TD=61 YIELDS ABOUT 1800 J/KG OF CAPE. THE STEERING FLOW IS
GENERALLY FROM THE EAST AT ABOUT 10 MPH. CURRENT SATELLITE AND RADAR
IMAGERY DEPICT CONVECTIVE SHOWERS MAINLY OVER THE CENTRAL AND
WESTERN DESERTS PUSHING WEST WITH PARTLY TO MOSTLY CLOUDY SKIES
MAINLY FROM DEBRIS CLOUDINESS FROM TUCSON EASTWARD. THERE IS A WELL
DEFINED SHEAR AXIS/DEFORMATION ZONE IN THE MID TO UPPER LEVELS LYING
RIGHT ACROSS THE CENTER OF THE FORECAST AREA TODAY WITH THE REMNANTS
OF AN INVERTED TROUGH. THE BIG QUESTION FOR TODAY IS HOW MUCH
CLEARING WILL WE SEE TO GENERATE SUSTAINED CONVECTION.
AFTER REVIEWING LATEST GUIDANCE...TEND TO FAVOR THE HRRR WHICH IS
HANDLING THE CURRENT CLOUD COVERAGE REALLY WELL ALONG WITH THE LIGHT
SHOWERS WEST OF TUCSON. THE HRRR IS MOST ORGANIZED WITH CONVECTION
THIS AFTERNOON AND EVENING ALONG WITH THE 12Z NAM FROM CENTRAL PIMA
COUNTY EASTWARD. MEANWHILE...THE EARLY 06Z UOFA WRF-GFS AND 12Z
WRF-NAM HAVE CLEARED THINGS OUT TOO QUICKLY. WITH THAT SAID...HAVE
GONE AHEAD AND RAISED POPS AREAWIDE FOR THIS AFTERNOON AND THIS
EVENING. WE THINK THE BEST CHANCE FOR HEAVIEST RAINFALL WILL BE FROM
THE TUCSON AREA EASTWARD. AS THE MORNING PROGRESSES AND SHOULD SKIES
CLEAR AND CONFIDENCE INCREASE...WILL CONSIDER A SHORTER FUSE FLASH
FLOOD WATCH.
&&
.AVIATION...SCT SHRA / ISOLD TSRA THRU FRIDAY MORNING OR 26/17Z.
MVFR CIGS/VSBYS WITH WIND GUSTS APPROACHING 45 KTS WITH THE
STRONGEST TSRA. TSRA COVERAGE INCREASING AFTER 26/17Z.
OTHERWISE...CLOUD DECKS MAINLY 6-10K FT AGL AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU THURSDAY EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ENHANCED MOISTURE WILL PROVIDE A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. OTHERWISE... THERE
WILL BE ENOUGH MOISTURE FOR SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS TO PREVAIL INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
GL
AREA FORECAST DISCUSSION
NWS TUCSON AZ
825 AM MST THU JUL 25 2013
.SYNOPSIS...A DISTURBANCE ALOFT ACROSS THE AREA WILL ENHANCE
THUNDERSTORM COVERAGE AND INTENSITY ACROSS MOST OF THE AREA TODAY.
SOME STORMS WILL GENERATE HEAVY RAINFALL. OTHERWISE...PLENTY OF
MOISTURE ACROSS THE REGION TO PROVIDE A CHANCE OF MAINLY AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND. A DECREASE
IN MOISTURE MAY LEAD TO LESS THUNDERSTORM ACTIVITY EARLY NEXT WEEK.
&&
.DISCUSSION...THE 12Z KTWC SOUNDING IS DEPICTING A VERY MOIST AND
UNSTABLE ATMOSPHERE. PWAT OF 1.96" IS IN THE 99TH PERCENTILE AND
ABOUT 160 PERCENT OF NORMAL FOR THIS TIME OF YEAR. MEANWHILE...THERE
IS CONSIDERABLY MORE MID LEVEL COOLING COMPARED TO 24 HOURS AGO WITH
THE STUBBORN INVERSION AT ABOUT 500 MB GONE. MODIFIED SOUNDING WITH
T=95 AND TD=61 YIELDS ABOUT 1800 J/KG OF CAPE. THE STEERING FLOW IS
GENERALLY FROM THE EAST AT ABOUT 10 MPH. CURRENT SATELLITE AND RADAR
IMAGERY DEPICT CONVECTIVE SHOWERS MAINLY OVER THE CENTRAL AND
WESTERN DESERTS PUSHING WEST WITH PARTLY TO MOSTLY CLOUDY SKIES
MAINLY FROM DEBRIS CLOUDINESS FROM TUCSON EASTWARD. THERE IS A WELL
DEFINED SHEAR AXIS/DEFORMATION ZONE IN THE MID TO UPPER LEVELS LYING
RIGHT ACROSS THE CENTER OF THE FORECAST AREA TODAY WITH THE REMNANTS
OF AN INVERTED TROUGH. THE BIG QUESTION FOR TODAY IS HOW MUCH
CLEARING WILL WE SEE TO GENERATE SUSTAINED CONVECTION.
AFTER REVIEWING LATEST GUIDANCE...TEND TO FAVOR THE HRRR WHICH IS
HANDLING THE CURRENT CLOUD COVERAGE REALLY WELL ALONG WITH THE LIGHT
SHOWERS WEST OF TUCSON. THE HRRR IS MOST ORGANIZED WITH CONVECTION
THIS AFTERNOON AND EVENING ALONG WITH THE 12Z NAM FROM CENTRAL PIMA
COUNTY EASTWARD. MEANWHILE...THE EARLY 06Z UOFA WRF-GFS AND 12Z
WRF-NAM HAVE CLEARED THINGS OUT TOO QUICKLY. WITH THAT SAID...HAVE
GONE AHEAD AND RAISED POPS AREAWIDE FOR THIS AFTERNOON AND THIS
EVENING. WE THINK THE BEST CHANCE FOR HEAVIEST RAINFALL WILL BE FROM
THE TUCSON AREA EASTWARD. AS THE MORNING PROGRESSES AND SHOULD SKIES
CLEAR AND CONFIDENCE INCREASE...WILL CONSIDER A SHORTER FUSE FLASH
FLOOD WATCH.
&&
.AVIATION...SCT SHRA / ISOLD TSRA THRU FRIDAY MORNING OR 26/17Z.
MVFR CIGS/VSBYS WITH WIND GUSTS APPROACHING 45 KTS WITH THE
STRONGEST TSRA. TSRA COVERAGE INCREASING AFTER 26/17Z.
OTHERWISE...CLOUD DECKS MAINLY 6-10K FT AGL AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU THURSDAY EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ENHANCED MOISTURE WILL PROVIDE A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. OTHERWISE... THERE
WILL BE ENOUGH MOISTURE FOR SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS TO PREVAIL INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
GL
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 AM MDT THU JUL 25 2013
.UPDATE...COMPLICATED WEATHER PATTERN TODAY WILL LEAD TO A LOW
CONFIDENCE FORECAST. A WAVE MOVING ACROSS EASTERN COLORADO AT THIS
TIME IS BRINGING RAIN SHOWERS AND CLOUDS TO NORTHEAST COLORADO. THIS
HAS SLOWED WARMING. A COLD FRONT WILL ENTER NORTHERN COLORADO SOON.
WINDS IN SOUTHERN WYOMING BEHIND THE FRONT ARE GUSTING TO 30 MPH
BEHIND THE FRONT. THIS WILL PUSH THROUGH THE AREA DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS. A SECOND WAVE OVER WYOMING AND
UTAH WILL PROGRESS EASTWARD TODAY AND TRIGGER SHOWERS AND STORMS
OVER THE HIGHER TERRAIN.
TEMPERATURES AT 700MB HAVE DECREASED. THE 12Z SOUNDING INDICATED A
CONVECTIVE TEMPERATURE OF 82 DEGREES. BIGGEST QUESTION IS...WILL THE
URBAN CORRIDOR AND EASTERN PLAINS BE TOO CAPPED FOR CONVECTION.
THE COOLER AIR SLIDING SOUTH MAY KEEP THE AREA FROM REACHING ITS
CONVECTIVE TEMPERATURE. HOWEVER THE FRONT MAY PRODUCE ENOUGH LIFT
TO TRIGGER CONVECTION. NOT SURE HOW THIS WILL PAN OUT AND WILL
KEEP SCATTERED POPS IN THE FORECAST. WILL LOWER TEMPERATURES A FEW
DEGREES BECAUSE OF THE CLOUD COVER AND COLD FRONT APPROACHING FROM
THE NORTH.
&&
.AVIATION...WINDS WILL BECOME NORTHERLY AS A COLD FRONT PUSHES
THROUGH THE AREA AROUND 18Z. WILL BE ANOTHER CHANCE FOR
THUNDERSTORMS THIS AFTERNOON AND EVENING. AN UPPER LEVEL SYSTEM
WILL MOVE OVER THE MOIST AIRMASS IN PLACE AND TRIGGER SCATTERED
THUNDERSTORMS. GUSTY OUTFLOW WINDS AND HEAVY RAIN WILL BE THE
BIGGEST CONCERNS. CHANCE FOR STORMS WILL END DURING THE EARLY
EVENING HOURS...BY 03Z. WINDS WILL SETTLE SOUTHERLY AROUND
MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 335 AM MDT THU JUL 25 2013/
SHORT TERM...A DISTURBANCE IS CURRENTLY OVER THE MTNS EARLY THIS
MORNING AND SHOULD EXIT NERN COLORADO BY LATE MORNING. AS THIS
FEATURE MOVES ACROSS THERE WILL BE A FEW SHOWERS AND POSSIBLY A
TSTM THRU THE MORNING HOURS.
FOR THIS AFTN QUITE A BIT OF SUBTROPICAL MOISTURE WILL REMAIN OVER
THE AREA WITH PRECIPITABLE WATER VALUES AROUND AN INCH. WOULD
EXPECT TSTMS TO REDEVELOP OVER THE HIGHER TERRAIN BY EARLY AFTN.
MEANWHILE OVER NERN CO A COOL FNT WILL BE NR THE WYOMING BORDER
AROUND 18Z AND THEN MOVE ACROSS THE PLAINS THRU THE AFTN. NOT SURE
HOW THINGS ARE GOING TO EVOLVE WITH THIS FNT AS FAR AS TSTM
DEVELOPMENT GOES OVER THE PLAINS. ITS POSSIBLY ACTIVITY COULD END
UP FOCUSING CLOSER TO THE FOOTHILLS AND OVER THE PALMER DIVIDE
WITH LIMITED ACTIVITY OVER THE PLAINS THRU THE AFTN. SHORT RANGE
MODELS ARE NOT MUCH HELP AS FAR AS DEFINING BEST AREAS FOR TSTMS
SO WILL JUST KEEP POPS IN THE CHC CATEGORY. OVERALL INSTABILITY
DOES NOT LOOK AS UNSTABLE AS WED WITH THE MID LVL FLOW SOMEWHAT
WEAKER SO SVR THREAT LOOKS LOW. STORMS WILL BE SLOWER MOVING WHICH
COULD LEAD TO HEAVY RAINFALL IN SOME AREAS. AS FAR AS TEMPS WILL
KEEP HIGHS MAINLY IN THE LOWER TO MID 80S OVER NERN CO.
FOR TONIGHT WITH THE FLOW OF SUBTROPICAL MOISTURE CONTINUING IN
THE MTNS SHOWERS AND A FEW STORMS COULD LINGER OVERNIGHT SO WILL
KEEP IN SOME LOW POPS. OVER NERN CO IT APPEARS TSTM ACTIVITY
SHOULD GRADUALLY END IN THE EARLY EVENING HOURS.
LONG TERM...THE NEXT WEEK CONTINUES TO LOOK ACTIVE AND WET ACROSS
THE FORECAST AREA. AN ELONGATED UPPER LEVEL HIGH PRESSURE RIDGE
WILL EXTEND ACROSS THE SOUTHERN TIER OF THE COUNTRY WITH MONSOONAL
MOISTURE ADVECTING ACROSS ARIZONA AND NEW MEXICO INTO UTAH AND
COLORADO. DAILY PRECIPITATION DISTRIBUTIONS ARE GOING TO DEPEND ON
MESOSCALE FEATURES LIKE STRENGTH OF UPSLOPE FLOW AND THE PRESENCE
OF A DENVER CYCLONE...AS WELL AS THE LOCATION OF PASSING WEAK
UPPER LEVEL JET STREAMS. THE LATEST RUN OF THE ECMWF POINTS TOWARD
SUNDAY AFTERNOON BEING A PARTICULARLY ACTIVE DAY WITH DECENT
SOUTHEASTERLY LOW LEVEL FLOW ACROSS EASTERN COLORADO AND WEAK
WESTERLY FLOW ALOFT. THE FEED OF SUB-TROPICAL MOISTURE LOOKS LIKE
IT WILL REMAIN IN PLACE THROUGH AT LEAST NEXT TUESDAY...SO THE
FORECAST WILL CONTINUE TO MENTION THE CHANCE OF THUNDERSTORMS EACH
DAY. ALONG WITH THE PERSISTENT CHANCES OF PRECIPITATION...
TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL BUT STILL
WARM ENOUGH TO PRODUCE THE INSTABILITY NECESSARY FOR DAILY
CONVECTION TO DEVELOP. PERIODS OF NOCTURNAL SHOWERS CAN ALSO NOT
BE RULED OUT LIKE WE ARE SEEING THIS MORNING.
AVIATION...MAY SEE A FEW -SHRA THIS MORNING AS DISTURBANCE MOVES
ACROSS BUT CEILINGS SHOULD STAY ABV 8000 FT. DO NOT HAVE A GOOD
FEEL FOR WINDS THIS MORNING HOWEVER WILL KEEP WINDS LIGHT NWLY
THRU MID MORNING AND THEN HAVE THEM BECOME MORE NNE BY EARLY AFTN
AS A FNT MOVES ACROSS. THE LATEST HRRR AND RAP INDICATES THERE
WOULD A CHC OF TSTMS IN THE 21Z-00Z TIME PERIOD SO WILL PUT IN A
PROP GROUP FOR -TSRA. FOR THIS EVENING TSTM THREAT SHOULD END BY
01Z WITH WINDS BECOMING DRAINAGE BY MIDNIGHT.
HYDROLOGY...THERE WILL BE SCATTERED THUNDERSTORMS THIS AFTERNOON
WITH SOME LOCALLY HEAVY RAIN POSSIBLE. THE STRONGER STORMS COULD
PRODUCE RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES WHICH COULD
LEAD TO SOME FLOODING ISSUES IF THEY TRACK ACROSS THE BURN SCARS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
335 AM MDT THU JUL 25 2013
.SHORT TERM...A DISTURBANCE IS CURRENTLY OVER THE MTNS EARLY THIS
MORNING AND SHOULD EXIT NERN COLORADO BY LATE MORNING. AS THIS
FEATURE MOVES ACROSS THERE WILL BE A FEW SHOWERS AND POSSIBLY A
TSTM THRU THE MORNING HOURS.
FOR THIS AFTN QUITE A BIT OF SUBTROPICAL MOISTURE WILL REMAIN OVER
THE AREA WITH PRECIPITABLE WATER VALUES AROUND AN INCH. WOULD
EXPECT TSTMS TO REDEVELOP OVER THE HIGHER TERRAIN BY EARLY AFTN.
MEANWHILE OVER NERN CO A COOL FNT WILL BE NR THE WYOMING BORDER
AROUND 18Z AND THEN MOVE ACROSS THE PLAINS THRU THE AFTN. NOT SURE
HOW THINGS ARE GOING TO EVOLVE WITH THIS FNT AS FAR AS TSTM
DEVELOPMENT GOES OVER THE PLAINS. ITS POSSIBLY ACTIVITY COULD END
UP FOCUSING CLOSER TO THE FOOTHILLS AND OVER THE PALMER DIVIDE
WITH LIMITED ACTIVITY OVER THE PLAINS THRU THE AFTN. SHORT RANGE
MODELS ARE NOT MUCH HELP AS FAR AS DEFINING BEST AREAS FOR TSTMS
SO WILL JUST KEEP POPS IN THE CHC CATEGORY. OVERALL INSTABILITY
DOES NOT LOOK AS UNSTABLE AS WED WITH THE MID LVL FLOW SOMEWHAT
WEAKER SO SVR THREAT LOOKS LOW. STORMS WILL BE SLOWER MOVING WHICH
COULD LEAD TO HEAVY RAINFALL IN SOME AREAS. AS FAR AS TEMPS WILL
KEEP HIGHS MAINLY IN THE LOWER TO MID 80S OVER NERN CO.
FOR TONIGHT WITH THE FLOW OF SUBTROPICAL MOISTURE CONTINUING IN
THE MTNS SHOWERS AND A FEW STORMS COULD LINGER OVERNIGHT SO WILL
KEEP IN SOME LOW POPS. OVER NERN CO IT APPEARS TSTM ACTIVITY
SHOULD GRADUALLY END IN THE EARLY EVENING HOURS.
.LONG TERM...THE NEXT WEEK CONTINUES TO LOOK ACTIVE AND WET ACROSS
THE FORECAST AREA. AN ELONGATED UPPER LEVEL HIGH PRESSURE RIDGE
WILL EXTEND ACROSS THE SOUTHERN TIER OF THE COUNTRY WITH MONSOONAL
MOISTURE ADVECTING ACROSS ARIZONA AND NEW MEXICO INTO UTAH AND
COLORADO. DAILY PRECIPITATION DISTRIBUTIONS ARE GOING TO DEPEND ON
MESOSCALE FEATURES LIKE STRENGTH OF UPSLOPE FLOW AND THE PRESENCE
OF A DENVER CYCLONE...AS WELL AS THE LOCATION OF PASSING WEAK
UPPER LEVEL JET STREAMS. THE LATEST RUN OF THE ECMWF POINTS TOWARD
SUNDAY AFTERNOON BEING A PARTICULARLY ACTIVE DAY WITH DECENT
SOUTHEASTERLY LOW LEVEL FLOW ACROSS EASTERN COLORADO AND WEAK
WESTERLY FLOW ALOFT. THE FEED OF SUB-TROPICAL MOISTURE LOOKS LIKE
IT WILL REMAIN IN PLACE THROUGH AT LEAST NEXT TUESDAY...SO THE
FORECAST WILL CONTINUE TO MENTION THE CHANCE OF THUNDERSTORMS EACH
DAY. ALONG WITH THE PERSISTENT CHANCES OF PRECIPITATION...
TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL BUT STILL
WARM ENOUGH TO PRODUCE THE INSTABILITY NECESSARY FOR DAILY
CONVECTION TO DEVELOP. PERIODS OF NOCTURNAL SHOWERS CAN ALSO NOT
BE RULED OUT LIKE WE ARE SEEING THIS MORNING.
&&
.AVIATION...MAY SEE A FEW -SHRA THIS MORNING AS DISTURBANCE MOVES
ACROSS BUT CEILINGS SHOULD STAY ABV 8000 FT. DO NOT HAVE A GOOD
FEEL FOR WINDS THIS MORNING HOWEVER WILL KEEP WINDS LIGHT NWLY
THRU MID MORNING AND THEN HAVE THEM BECOME MORE NNE BY EARLY AFTN
AS A FNT MOVES ACROSS. THE LATEST HRRR AND RAP INDICATES THERE
WOULD A CHC OF TSTMS IN THE 21Z-00Z TIME PERIOD SO WILL PUT IN A
PROP GROUP FOR -TSRA. FOR THIS EVENING TSTM THREAT SHOULD END BY
01Z WITH WINDS BECOMING DRAINAGE BY MIDNIGHT.
&&
.HYDROLOGY...THERE WILL BE SCATTERED THUNDERSTORMS THIS AFTERNOON
WITH SOME LOCALLY HEAVY RAIN POSSIBLE. THE STRONGER STORMS COULD
PRODUCE RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES WHICH COULD
LEAD TO SOME FLOODING ISSUES IF THEY TRACK ACROSS THE BURN SCARS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1032 PM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE EAST OF CAPE COD CONTINUES TO DEPART AS WEAK HIGH
PRESSURE BUILDS INTO THE REGION THROUGH SATURDAY. AN OCCLUDED FRONT
APPROACHES FROM THE WEST ON SATURDAY NIGHT AND SUNDAY...THEN
CROSSES THE TRI-STATE SUNDAY NIGHT AND MONDAY MORNING. HIGH PRESSURE
RETURNS THEREAFTER AND REMAINS IN PLACE THROUGH MID- WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
PER LATEST WATER VAPOR IMAGERY AND TRENDS IN RUC ANALYSIS...DEEP
LAYERED RIDGING BUILDS OVER THE AREA OVERNIGHT...WITH ASSOCIATED
SUBSIDENCE PROMOTING LIGHT WINDS AND MINIMAL...IF ANY CLOUD COVER.
WITH WINDS LIGHT...ADVECTION OF MOISTURE WILL NOT BE ALL THAT
STRONG...SO CONFIDENCE IN PATCHY FOG REDUCING VISIBILITIES TO
UNDER 3 MILES IS LOW. AS A RESULT...HAVE REMOVED PATCHY FOG FROM
THE FORECAST. THIS IS CONSISTENT WITH THE FOG TOOL IN BUFKIT
SHOWING THE ONLY AREA THAT MAY SEE SOME FOG IS AROUND KSWF...BUT
WITH LITTLE IF ANY FORECAST AT KPOU OR KHPN...DID NOT HAVE
CONFIDENCE TO JUST PUT THE PATCHY FOG IN INTERIOR PORTIONS OF THE
LOWER HUDSON VALLEY.
WITH DECENT RADIATIONAL COOLING FORECAST...DID BUMP LOWS DOWN A
DEGREE OR SO OUTSIDE OF URBAN AREAS...CONSISTENT WITH A BLEND OF
18Z MAV AND 12Z MET GUIDANCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS THROUGH THE REGION AND DEPARTS ON SATURDAY
AFTERNOON. MEANWHILE...LOW PRES TRACKING ACROSS THE GREAT LAKES
AND INTO EASTERN CANADA WILL DRAG A COLD FRONT THROUGH THE OHIO
VALLEY DURING THE DAY. AHEAD OF THAT FRONT...A PRE-FRONTAL TROUGH
WILL DEVELOP...PRODUCING SHOWERS AND THUNDERSTORMS ACROSS THE
APPALACHIANS. THE BACKSIDE OF THE NOW OFFSHORE HIGH LOOKS TO KEEP
MOST OF THE STORMS AT BAY FOR MOST OF THE DAY.
12Z NAM AND 12Z GFS KEEP THE PRECIP WEST OF THE LOCAL AREA
THROUGH 00Z SUNDAY. AS A RESULT...WILL ONLY CARRY SLIGHT CHANCE
POPS FOR FAR WESTERN ZONES LATE SATURDAY AFTERNOON. FOR THE REST
OF THE AREA AND THE REST OF SATURDAY...EXPECTING A DRY FORECAST
WITH MODERATING TEMPS. AS THE HIGH CONTINUES TO DEPART AND THE
COLD FRONT CONTINUES ITS APPROACH FROM THE WEST...SHOWERS AND
THUNDERSTORMS WILL DEVELOP FROM WEST TO EAST SATURDAY NIGHT. FOR
NOW...WILL KEEP POPS CAPPED AT CHANCE.
HIGHS ON SATURDAY WILL BE CLOSER TO THE SEASONAL AVERAGE...
GENERALLY TOPPING OFF IN THE LOW TO MID 80S...WITH COOLER TEMPS
NEAR THE SHORES. A MUGGY NIGHT ON TAP SATURDAY NIGHT WITH LOWS
GENERALLY IN THE UPPER 60S TO LOWER 70S.
THERE IS A MODERATE RISK OF RIP CURRENTS AT AREA ATLANTIC BEACHES
FROM SATURDAY INTO SATURDAY EVENING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES THE AREA ON SUNDAY. SHOWERS AND A CHANCE
OF THUNDERSTORM BECOME LIKELY BY DAY`S END FROM ROUGHLY THE CITY
AND POINTS WEST. STILL A DECENT CHANCE FARTHER EAST. HIGH TEMPS
SLIGHTLY BELOW NORMAL. BEST CHANCES OF SHOWERS AND STORMS WILL BE
SUNDAY NIGHT WITH THE PASSAGE OF THE COLD FRONT. PRECIPITABLE
WATERS WILL BE ON THE HIGH SIDE...SO SOME SPOTS WILL PROBABLY SEE
SOME HEAVY DOWNPOURS.
HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT MONDAY
MORNING. SO OUTSIDE OF LINGERING MORNING SHOWERS EAST OF THE
CITY...CLEARING CONDITIONS AND DRY WEATHER ALONG WITH HIGHS A
LITTLE BELOW NORMAL. TUESDAY SHOULD BE SIMILAR TO MONDAY...EXCEPT
COMPLETELY DRY ACROSS THE TRI STATE AREA AND FEWER CLOUDS. HIGH
PRESSURE REMAINS IN CONTROL OF THE WEATHER ON WEDNESDAY. PARTLY
CLOUDY WITH NEAR NORMAL HIGHS.
A STORM SYSTEM APPROACHES FROM THE WEST WEDNESDAY NIGHT WITH A
SLIGHT CHANCE OF SHOWERS. THEN A BETTER CHANCE OF SHOWERS AND
POSSIBLY SOME THUNDERSTORMS THURSDAY AND THURSDAY NIGHT AS THE
SYSTEM PASSES THROUGH. IMPROVING CONDITIONS ON FRIDAY AS HIGH
PRESSURE BUILDS BACK IN. CLOUDS WILL KEEP THURSDAY`S HIGHS A
LITTLE BELOW NORMAL...THEN A RETURN TO NORMAL TEMPERATURES ON
FRIDAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR THROUGH THE PERIOD.
LIGHT AND VARIABLE WIND OVERNIGHT...EXCEPT AT THE NYC TERMINALS
WHERE WIND WILL BE SOUTHWESTERLY AROUND 5 KT. WIND INCREASES TO 5 TO
10 KT SATURDAY MORNING FROM THE SOUTH...INCREASING TO AROUND 10 KT
IN THE AFTERNOON.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT...VFR...POSSIBLY MVFR CEILINGS LATE AS SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOP.
.SUNDAY-SUNDAY NIGHT...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSTMS.
.MONDAY...SHOWERS ENDING WITH CONDITIONS IMPROVING TO VFR.
.TUESDAY-WEDNESDAY...VFR.
&&
.MARINE...
MINOR CHANGES MADE THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
HIGH PRES BUILDS OVER THE WATERS AND DEPARTS ON SATURDAY...WITH
TRANQUIL CONDITIONS FOR THE FIRST HALF OF THE WEEKEND AS A RESULT.
SUB-SCA CONDITIONS CONTINUE THROUGH THE REST OF THE FORECAST
PERIOD AS WINDS REMAIN AROUND 10 KT OR LESS...AND SEAS REMAIN BELOW
5 FT.
&&
.HYDROLOGY...
DRY CONDITIONS...OTHER THAN MAYBE A LINGERING -SHRA OVER FAR
EASTERN AREAS THROUGH 00Z TONIGHT...THROUGH SATURDAY.
HIGH MOISTURE CONTENT WITH PRECIPITABLE WATERS BETWEEN 1.75 AND 2
INCHES SATURDAY NIGHT THROUGH MONDAY WILL LIKELY PRODUCE HEAVY
RAIN AT TIMES...ESPECIALLY IN THUNDERSTORM ACTIVITY. LOCALIZED
URBAN AND SMALL STREAM FLOODING IS A POSSIBILITY...ALTHOUGH WITH
LOW CONFIDENCE AT THIS TIME.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/MALOIT/MPS
NEAR TERM...MALOIT
SHORT TERM...MALOIT/MPS
LONG TERM...JC
AVIATION...MET
MARINE...JC/MALOIT/MPS
HYDROLOGY...JC/MALOIT/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
945 PM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE EAST OF CAPE COD CONTINUES TO DEPART AS WEAK HIGH
PRESSURE BUILDS INTO THE REGION THROUGH SATURDAY. AN OCCLUDED FRONT
APPROACHES FROM THE WEST ON SATURDAY NIGHT AND SUNDAY...THEN
CROSSES THE TRI-STATE SUNDAY NIGHT AND MONDAY MORNING. HIGH PRESSURE
RETURNS THEREAFTER AND REMAINS IN PLACE THROUGH MID- WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
PER LATEST WATER VAPOR IMAGERY AND TRENDS IN RUC ANALYSIS...DEEP
LAYERED RIDGING BUILDS OVER THE AREA OVERNIGHT...WITH ASSOCIATED
SUBSIDENCE PROMOTING LIGHT WINDS AND MINIMAL...IF ANY CLOUD COVER.
WITH WINDS LIGHT...ADVECTION OF MOISTURE WILL NOT BE ALL THAT
STRONG...SO CONFIDENCE IN PATCHY FOG REDUCING VISIBILITIES TO
UNDER 3 MILES IS LOW. AS A RESULT...HAVE REMOVED PATCHY FOG FROM
THE FORECAST. THIS IS CONSISTENT WITH THE FOG TOOL IN BUFKIT
SHOWING THE ONLY AREA THAT MAY SEE SOME FOG IS AROUND KSWF...BUT
WITH LITTLE IF ANY FORECAST AT KPOU OR KHPN...DID NOT HAVE
CONFIDENCE TO JUST PUT THE PATCHY FOG IN INTERIOR PORTIONS OF THE
LOWER HUDSON VALLEY.
WITH DECENT RADIATIONAL COOLING FORECAST...DID BUMP LOWS DOWN A
DEGREE OR SO OUTSIDE OF URBAN AREAS...CONSISTENT WITH A BLEND OF
18Z MAV AND 12Z MET GUIDANCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS THROUGH THE REGION AND DEPARTS ON SATURDAY
AFTERNOON. MEANWHILE...LOW PRES TRACKING ACROSS THE GREAT LAKES
AND INTO EASTERN CANADA WILL DRAG A COLD FRONT THROUGH THE OHIO
VALLEY DURING THE DAY. AHEAD OF THAT FRONT...A PRE-FRONTAL TROUGH
WILL DEVELOP...PRODUCING SHOWERS AND THUNDERSTORMS ACROSS THE
APPALACHIANS. THE BACKSIDE OF THE NOW OFFSHORE HIGH LOOKS TO KEEP
MOST OF THE STORMS AT BAY FOR MOST OF THE DAY.
12Z NAM AND 12Z GFS KEEP THE PRECIP WEST OF THE LOCAL AREA
THROUGH 00Z SUNDAY. AS A RESULT...WILL ONLY CARRY SLIGHT CHANCE
POPS FOR FAR WESTERN ZONES LATE SATURDAY AFTERNOON. FOR THE REST
OF THE AREA AND THE REST OF SATURDAY...EXPECTING A DRY FORECAST
WITH MODERATING TEMPS. AS THE HIGH CONTINUES TO DEPART AND THE
COLD FRONT CONTINUES ITS APPROACH FROM THE WEST...SHOWERS AND
THUNDERSTORMS WILL DEVELOP FROM WEST TO EAST SATURDAY NIGHT. FOR
NOW...WILL KEEP POPS CAPPED AT CHANCE.
HIGHS ON SATURDAY WILL BE CLOSER TO THE SEASONAL AVERAGE...
GENERALLY TOPPING OFF IN THE LOW TO MID 80S...WITH COOLER TEMPS
NEAR THE SHORES. A MUGGY NIGHT ON TAP SATURDAY NIGHT WITH LOWS
GENERALLY IN THE UPPER 60S TO LOWER 70S.
THERE IS A MODERATE RISK OF RIP CURRENTS AT AREA ATLANTIC BEACHES
FROM SATURDAY INTO SATURDAY EVENING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES THE AREA ON SUNDAY. SHOWERS AND A CHANCE
OF THUNDERSTORM BECOME LIKELY BY DAY`S END FROM ROUGHLY THE CITY
AND POINTS WEST. STILL A DECENT CHANCE FARTHER EAST. HIGH TEMPS
SLIGHTLY BELOW NORMAL. BEST CHANCES OF SHOWERS AND STORMS WILL BE
SUNDAY NIGHT WITH THE PASSAGE OF THE COLD FRONT. PRECIPITABLE
WATERS WILL BE ON THE HIGH SIDE...SO SOME SPOTS WILL PROBABLY SEE
SOME HEAVY DOWNPOURS.
HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT MONDAY
MORNING. SO OUTSIDE OF LINGERING MORNING SHOWERS EAST OF THE
CITY...CLEARING CONDITIONS AND DRY WEATHER ALONG WITH HIGHS A
LITTLE BELOW NORMAL. TUESDAY SHOULD BE SIMILAR TO MONDAY...EXCEPT
COMPLETELY DRY ACROSS THE TRI STATE AREA AND FEWER CLOUDS. HIGH
PRESSURE REMAINS IN CONTROL OF THE WEATHER ON WEDNESDAY. PARTLY
CLOUDY WITH NEAR NORMAL HIGHS.
A STORM SYSTEM APPROACHES FROM THE WEST WEDNESDAY NIGHT WITH A
SLIGHT CHANCE OF SHOWERS. THEN A BETTER CHANCE OF SHOWERS AND
POSSIBLY SOME THUNDERSTORMS THURSDAY AND THURSDAY NIGHT AS THE
SYSTEM PASSES THROUGH. IMPROVING CONDITIONS ON FRIDAY AS HIGH
PRESSURE BUILDS BACK IN. CLOUDS WILL KEEP THURSDAY`S HIGHS A
LITTLE BELOW NORMAL...THEN A RETURN TO NORMAL TEMPERATURES ON
FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR THROUGH THE PERIOD.
LIGHT AND VARIABLE WIND OVERNIGHT...EXCEPT COASTAL TERMINALS AS SEA
BREEZE WEAKENS THROUGH 03Z AND SEA BREEZE WIND BECOMES
SOUTHWESTERLY. WIND INCREASES TO 5 TO 10 KT SATURDAY FROM THE
SOUTH...INCREASING TO AROUND 10 KT IN THE AFTERNOON.
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)
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT...VFR...POSSIBLY MVFR CEILINGS LATE AS SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOP.
.SUNDAY-SUNDAY NIGHT...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSTMS.
.MONDAY...SHOWERS ENDING WITH CONDITIONS IMPROVING TO VFR.
.TUESDAY-WEDNESDAY...VFR.
&&
.MARINE...
MINOR CHANGES MADE THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
HIGH PRES BUILDS OVER THE WATERS AND DEPARTS ON SATURDAY...WITH
TRANQUIL CONDITIONS FOR THE FIRST HALF OF THE WEEKEND AS A RESULT.
SUB-SCA CONDITIONS CONTINUE THROUGH THE REST OF THE FORECAST
PERIOD AS WINDS REMAIN AROUND 10 KT OR LESS...AND SEAS REMAIN BELOW
5 FT.
&&
.HYDROLOGY...
DRY CONDITIONS...OTHER THAN MAYBE A LINGERING -SHRA OVER FAR
EASTERN AREAS THROUGH 00Z TONIGHT...THROUGH SATURDAY.
HIGH MOISTURE CONTENT WITH PRECIPITABLE WATERS BETWEEN 1.75 AND 2
INCHES SATURDAY NIGHT THROUGH MONDAY WILL LIKELY PRODUCE HEAVY
RAIN AT TIMES...ESPECIALLY IN THUNDERSTORM ACTIVITY. LOCALIZED
URBAN AND SMALL STREAM FLOODING IS A POSSIBILITY...ALTHOUGH WITH
LOW CONFIDENCE AT THIS TIME.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/MPS
NEAR TERM...MALOIT
SHORT TERM...MPS/MALOIT
LONG TERM...JC
AVIATION...MET
MARINE...MALOIT/MPS/JC
HYDROLOGY...MALOIT/MPS/JC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
745 PM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE TRACKS INTO MAINE AND THE CANADIAN MARITIMES WITH
SHOWERS ENDING THIS EVENING. DRY AND SUMMER LIKE WEATHER RETURNS
FOR SATURDAY WITH AN INCREASING CHANCE FOR SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY. A COMPLEX PATTERN OF FRONTS
SHOULD APPROACH SOUTHERN NEW ENGLAND LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
730 PM UPDATE...
LIGHT RAIN CONTINUES TO LINGER ALONG THE EASTERN MA COAST THIS
EVENING. EXPECTING THIS RAINFALL TO GRADUALYL MOVE OUT TO SEA THIS
EVENING. 26/19Z AND 26/20Z HRRR SEEMED TO HAVE THE BEST HANDLE ON
THIS RAINFALL. AS SUCH USED THAT GUIDANCE AS THE BASIS FOR
UPDATING TIMING RAIN DEPARTURE THIS EVENING.
TWEAKED TEMPERATURES AND DEW POINTS TO BRING THEM BACK IN LINE
WITH OBSERVED TRENDS.
PREVIOUS DISCUSSION...
WEAKENING COLD CONVEYOR CONTINUES OVER THE REGION AS LOW PRES
EXITS THE GULF OF MAINE AND SLIDES INTO MAINE AND THE CANADIAN
MARITIMES. STILL HAVE JUST ENOUGH DEFORMATION IN THIS EXITING
CONVEYOR TO LEAD TO CONTINUED RAIN SHOWERS WHICH WILL LIKELY TAKE
MOST OF THE EVENING TO FULLY DISSIPATE AND SHIFT OUT OF SRN NEW
ENGLAND. AS THE BATCH OF RAIN OVER LONG ISLAND BEGINS TO SHIFT
N...EXPECT THAT IT SHOULD WEAKEN AND BE THE LAST CALL FOR PRECIP
ASSOCIATED WITH THIS ANOMALOUS WARM SEASON STORM. WEAK SMALL
SCALE MID LVL RIDGING WILL BE BUILDING IN FROM THE W LEADING TO
DECENT SUBSIDENCE INVERSION ALOFT...TRAPPING SOME OF THIS LEFTOVER
MOISTURE IN THE NEAR SFC REGION. THEREFORE...LOW AND MID CLOUDS
TOO MAY TAKE THROUGH ABOUT MIDNIGHT TO CLEAR OUT THEMSELVES.
OTHERWISE...EXPECT SOME COOLING TONIGHT WITH MIN TEMPS DIPPING
INTO THE MID 5OS TO LOW 60S TOWARD DAYBREAK AS SKIES ARE ALLOWED
TO CLEAR. THE ONLY FLY IN THE OINTMENT WILL BE THE DEVELOPMENT OF
SOME PATCHY /AND POTENTIALLY DENSE IN SOME LOCALIZED SPOTS/ FOG
GIVEN THE TRAPPED LOW LVL MOISTURE AND MOIST SFCS. NOT CONFIDENT
ENOUGH IN ANY ONE LOCATION TO INITIATE A DENSE FOG ADVISORY BUT
THIS WILL HAVE TO BE WATCHED AS THE NIGHT GOES ON.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
TOMORROW...GENERALLY NICE DAY ACROSS THE REGION WITH SKIES
STARTING OFF PARTLY SUNNY. H85 TEMPS AVERAGE ABOUT +14C AND SHOULD
MIX CLOSE TO THIS LVL DESPITE THE CAPPING SUBSIDENCE OVERHEAD.
THEREFORE...EXPECT SFC MAXES IN THE MID TO EVEN A FEW UPPER 80S
ACROSS THE REGION WITH SOME SUNSHINE. FLOW WILL BE SHIFTING TO THE
S WITH TIME SO EXPECT GRADUALLY INCREASING DWPTS DURING THE DAY.
NOT AS HUMID AS SOME DAYS EARLIER THIS SUMMER...BUT STILL A BIT
MORE HUMID THAN WITH THE COOLER WX WE HAVE BEEN EXPERIENCING OF
LATE.
NOT ANTICIPATING ANY PRECIPITATION EVEN THOUGH JUST UPSTREAM IN
NY/PA A COLD FRONT WILL BE APPROACHING. WARM CAPPING SUBSIDENCE
INVERSION WITH H7 TEMPS NEAR +10C AND LITTLE SOURCE FOR LIFT
SHOULD KEEP SRN NEW ENGLAND MOSTLY DRY.
SAT NIGHT...
THE MOSTLY DRY WX CONTINUES INTO THE EARLY OVERNIGHT HOURS SAT
NIGHT. RETURN FLOW WILL ALLOW FOR COLUMN MOISTURE
INCREASE...INCREASING CLOUDS...AND THEREFORE A MORE MILD AND HUMID
NIGHT IN COMPARISON TO TONIGHT. MIN TEMPS ONLY EXPECTED TO DIP
INTO THE MID TO UPPER 60S.
THE NIGHT MAY NOT BE ENTIRELY DRY HOWEVER...AM NOTING THAT SOME
CONVECTION MAY FORM ALONG A WEAK CONVERGENT BOUNDARY STATIONED
WELL SOUTHEAST OF THE AREA...WITH A MODEST 20-30 KT LLJ ATTENDANT
TO THE CONVECTION. THIS MAY BE ENOUGH TO YIELD SOME LATE
NIGHT/EARLY MORNING SHOWERS AND T-STORMS PARTICULARLY ACROSS THE
SOUTHERN WATERS...AND SOUTH COASTAL LOCATIONS OF RI/SE MASS. THE
PRIMARY THREAT WITH ANY STORMS THE DEVELOP WOULD BE PERIODS OF
HEAVY RAIN. HAVE INCREASING POPS BASED ON LATEST GFS/ECMWF TIMING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* WARMER AND MORE HUMID WEATHER RETURNS THIS WEEKEND
* DRY SAT...BUT WET WEATHER RETURNS SUN AND POSSIBLY INTO MON
* TREND NEXT TUE & WED IS FOR DRIER WEATHER AND NOT AS WARM
SYNOPTIC OVERVIEW...
ENSEMBLES AND DETERMINISTIC GUIDANCE CONTINUE TO INDICATE A NEGATIVE
NAO AND AO ALONG WITH A PNA TRENDING POSITIVE THIS PERIOD. THIS WILL
SUPPORT AN ACTIVE AND SUPPRESSED POLAR JET ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND. THIS FLOW REGIME WILL FAVOR TEMPS AT OR
SLIGHTLY COOLER THAN NORMAL. AS FOR PRECIP...AN ANOMALOUS AND
SUPPRESSED POLAR JET WILL RESULT IN AN ACTIVE WEATHER PATTERN FOR
SOUTHERN NEW ENGLAND WITH POTENTIAL FOR HEAVY RAIN AND CONVECTION
SUN INTO MON.
SENSIBLE WEATHER...
SUNDAY/MONDAY...A FAIRLY DEEP UPPER LOW OVER THE NORTHERN GREAT
LAKES WITH H5 HEIGHTS OF MINUS 2 TO 3 STD FROM CLIMATOLOGY WILL
MOVE NORTHEAST INTO ONTARIO AND QUEBEC. THIS AMPLIFIED FLOW SHOULD
RECAPTURE A TROPICAL PLUME OFF THE EAST COAST AND PULL IT BACK
TOWARD OUR REGION. THIS...COMBINED WITH STRONG JET DYNAMICS...WILL
INCREASE THE RISK OF HEAVY RAINFALL DURING THIS TIME. THERE IS A
LOW RISK OF EMBEDDED THUNDERSTORMS ACROSS WESTERN NEW ENGLAND IN
LOW CAPE/HIGH SHEAR ENVIRONMENT. IT APPEARS THE RAINFALL MAY COME
IN TWO BATCHES. FIRST A ROUND OF SHOWERS/THUNDERSTORMS MOVING OFF
THE OCEAN SOUTH OF NEW ENGLAND INTO RI AND SOUTHEAST MA EARLY
SUNDAY MORNING. THE SECOND ROUND SHOULD BE LATER IN THE DAY
ACROSS WESTERN NEW ENGLAND AS A FRONT APPROACHES.
TUESDAY/WEDNESDAY...BY THE MIDDLE OF NEXT WEEK...THE LOW PRESSURE
OVER QUEBEC MOVES FARTHER NORTHEAST. THE NORTHERN STREAM OF THE
POLAR JET DEAMPLIFIES SOMEWHAT...YIELDING A BROAD LOW AMPLITUDE
TROUGH ACROSS THE GREAT LAKES AND SOUTHEAST CANADA. THIS WILL
FAVOR TEMPERATURES AT OR COOLER THAN NORMAL. AS FOR RAINFALL
CHANCES...TUESDAY LOOKS DRY BEHIND A FRONTAL PASSAGE LATE MONDAY.
DRY WEATHER MAY LINGER INTO WEDNESDAY.
THURSDAY/FRIDAY...A COMPLEX PATTERN OF FRONTS OF A WARM FRONT TO
OUR SOUTH THURSDAY...FOLLOWED BY A COLD FRONT LIKELY ARRIVING LATE
THURSDAY NIGHT INTO FRIDAY...SHOULD LEAD TO ANOTHER ROUND OF
SCATTERED SHOWERS DURING THIS TIME.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...HIGH CONFIDENCE IN OVERALL TRENDS...LOWER CONFIDENCE IN
EXACT TAF TIMING.
EXPECTING GRADUAL IMPROVEMENT FROM THE CURRENT MVFR/IFR MIX ACROSS
THE REGION WITH VFR BECOMING DOMINANT THIS EVENING. SOME
TERMINALS...PARTICULARLY CAPE/ISLAND TERMINALS...MAY TAKE UNTIL
LATE EVENING TO FULLY SCOUR OUT. HOWEVER...FEEL MOST LOCATIONS SEE
AT LEAST A BRIEF PERIOD OF VFR AS WINDS SHIFT MORE TOWARD THE W.
OVERNIGHT...SOME GROUND FOG MAY DEVELOP LATE TONIGHT...
PARTICULARLY AT THOSE AIRPORTS THAT SAW MORE RAIN TODAY.
TYPICALLY PRONE AIRPORTS WILL HAVE THE HIGEST RISK. EXPECTING
SOME MVFR/IFR VSBYS WITH THIS FOG BEGINNING ESPECIALLY AFTER 04Z
AND CONTINUING THROUGH ABOUT 12Z. CONDITIONS IMPROVE TO VFR FOR
SATURDAY.
KBOS TERMINAL...
HIGH CONFIDENCE IN TAF TRENDS...BUT LOWER CONFIDENCE IN TIMING FOR
IMPROVEMENT OVER THE NEXT FEW HOURS. VFR REMAINS DOMINANT INTO
SATURDAY NIGHT.
KBDL TERMINAL...
HIGH CONFIDENCE VFR REMAINS DOMINANT CATEGORY THROUGH SAT NIGHT.
LOW CONFIDENCE IN SOME GROUND FOG WITH PERIOD OF MVFR VSBYS LATE
TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...MVFR POSSIBLE IN SHOWERS/SCT TSTMS. IFR POSSIBLE IN LOW
CLOUDS/FOG EASTERN MA. MODERATE FORECAST CONFIDENCE.
MONDAY...IFR/MVFR IN SHOWERS/FOG TO START BUT TRENDING TOWARD VFR
LATE. MODERATE CONFIDENCE.
TUESDAY AND WEDNESDAY...VFR. MODERATE TO HIGH CONFIDENCE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN EXACT TIMING OF
DIMINISHING SEAS.
WITH LOW PRES SLIDING INTO MAINE AND THE MARITIMES...EXPECTING
GRADUAL IMPROVEMENT OVER THE WATERS THIS EVENING INTO EARLY SAT.
SEAS SHOULD DROP BELOW 5 FT ON THE NEAR COASTAL WATERS DURING
THE EVENING AND OVERNIGHT HOURS...THEN DURING THE MORNING HOURS
FOR THE OCEAN WATERS TOMORROW. WILL ALLOW THE NEAR SHORE WATERS
SMALL CRAFT ADVISORY TO EXPIRE AT 8 PM. IT MAY BE AN HOUR TOO SOON
FOR A FEW SPOTS...BUT THE WITH THE TREND SOLIDLY DOWNWARD DO NOT
THINK IT IS WORTH EXTENDING JUST 1 MORE HOUR.
QUIET BOATING WEATHER THEN PREVAILS INTO SAT NIGHT...SAVE FOR
SOME 20 KT GUSTS NEAR THE CAPE/ISLANDS SAT AFTERNOON AND THE
POSSIBILITY OF SOME EARLY MORNING THUNDERSHOWERS ALONG ESPECIALLY
THE SOUTH COASTAL WATERS SUN MORNING.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...SSW WINDS AHEAD OF APPROACHING FRONT. HEAVY
SHOWERS/ISOLATED TSTMS AND PATCHY FOG IN THE MORNING AND NIGHT.
MONDAY...COLD FRONT EXITS DURING THE AM. WIND SHIFT FROM SSW TO W
DURING THE AFTERNOON. LOW RISK OF SHOWERS AND FOG IN THE AM.
TUESDAY. AND WEDNESDAY...SHAPING UP TO BE A FINE BOATING DAY WITH
WNW WINDS AS HIGH PRES BUILDS IN FROM THE WEST. DRY WEATHER AND
GOOD VSBY SO FAR.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT THIS
EVENING FOR ANZ231>234-251.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM EDT
SATURDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT
SATURDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...DOODY/BELK
NEAR TERM...BELK/DOODY
SHORT TERM...DOODY
LONG TERM...BELK
AVIATION...DOODY/BELK
MARINE...DOODY/BELK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
927 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. THIS LOW
MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT...AND INTO THE CANADIAN
MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO THE
LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER COLD
FRONT WILL BE APPROACHING FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...WITH JUST ISOLATED THUNDER. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO THE NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL
ALLOW FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER
LEVEL CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY
AND SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST
FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY AND
SUNDAY NIGHT. A RETURNING DRYING TREND FOR MONDAY FROM WEST TO
EAST WITH SLIGHT CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
BASED ON THE PREVIOUS HIGH TIDE CYCLE...A LOWERING ASTRONOMICAL
TIDE...AND WIND FORECAST...NOT EXPECTING MINOR COASTAL FLOODING
THIS AFTERNOON AND TONIGHT...BUT WILL NEED TO KEEP AN EYE ON THIS
AS BENCHMARKS PROBABLY WILL NOT BE MISSED BY MUCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
806 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO THE NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL
ALLOW FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER
LEVEL CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY
AND SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST
FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY AND
SUNDAY NIGHT. A RETURNING DRYING TREND FOR MONDAY FROM WEST TO
EAST WITH SLIGHT CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
748 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW
FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL
CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND
SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE
NORTHEAST FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
443 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW
FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL
CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND
SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE
NORTHEAST FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
440 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO
THE CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS
INTO THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE THEREAFTER...BUILDING
IN FROM THE WEST. THIS WILL EVENTUALLY WEAKEN BY MID NEXT
WEEK...WITH WEAK LOW PRESSURE BEGINNING TO APPROACH FROM THE SOUTH.
.LONG TERM...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW FOR
A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL CLOSED
LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND SUNDAY NIGHT.
THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND FLATTEN WITH WITH LESS
AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST FOR EARLY TO MID NEXT
WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
439 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO
THE CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS
INTO THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE THEREAFTER...BUILDING
IN FROM THE WEST. THIS WILL EVENTUALLY WEAKEN BY MID NEXT
WEEK...WITH WEAK LOW PRESSURE BEGINNING TO APPROACH FROM THE SOUTH.
.LONG TERM...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW FOR
A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL CLOSED
LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND SUNDAY NIGHT.
THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND FLATTEN WITH WITH LESS
AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST FOR EARLY TO MID NEXT
WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
931 PM EDT FRI JUL 26 2013
...ANOTHER ACTIVE TSTORM DAY EXPECTED INTERIOR-EAST SATURDAY
AFTERNOON WITH LOCALLY HEAVY RAINFALL POSSIBLE...
.UPDATE...CONVECTION IS FADING AWAY. WILL MAINTAIN LOWERING POPS
NEXT COUPLE OF HOURS WITH JUST A SLIGHT CHANCE EAST COAST
OVERNIGHT.
A TROUGH WILL REMAIN IN THE VICINITY OF THE LAKE REGION
ON SATURDAY WITH PWATS INCREASING TO 2"+ ALONG WITH CONTINUED
INSTABILITY. AS A RESULT, WE EXPECT A STORMY AFTERNOON SATURDAY -
FOCUSED INTERIOR AND EAST COAST. HAVE INCREASED POPS ACROSS THESE
AREAS GIVEN HIGH CONFIDENCE IN THIS EXPECTATION. CONCERN TOMORROW
WILL BE LOCALIZED HIGH RAIN AMOUNTS DUE TO A SLOW STORM MOTION
FROM THE WEST...SO IF STORMS SET UP AND TRAIN OVER THE EAST COAST
METRO AREA, URBAN FLOODING WOULD BECOME A CONCERN. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 753 PM EDT FRI JUL 26 2013/
UPDATE...POPS/WEATHER UPDATED TO REFLECT THE NUMEROUS-WIDESPREAD
ACTIVITY WHICH DEVELOPED INTO BROWARD COUNTY AND NOW MOVING INTO
MIAMI-DADE WHILE WEAKENING. ADDITIONAL CONVECTION IS MOVING SOUTH
INTO THE LAKE OKEECHOBEE REGION FROM CENTRAL FL. HRRR SHOWS THIS
ACTIVITY DIMINISHING WITH LOSS OF HEATING. WILL WATCH THIS
CLOSELY, BUT FOR NOW DO EXPECT ONLY ISOLATED ACTIVITY EAST COAST
OVERNIGHT. /GREGORIA
AVIATION...WITH THE EXCEPTION OF TERMINAL KPBI...REMAINING EAST
COAST TERMINALS ASSIGNED VCTS OR TSRA FOR THE NEXT HOUR OR TWO.
HOWEVER THE LINE OF SHOWERS AND THUNDERSTORMS THAT PROMPTED THIS
IS BEGINNING TO DISSIPATE WITH THE MOST ACTIVE THUNDERSTORMS NOW
OVER THE ADJACENT ATLANTIC WATERS. BUT LINGERING SHOWERS AND/OR A
THUNDERSTORM COULD AFFECT THE AFOREMENTIONED TERMINALS IN THE
SHORT TERM...WITH SUB-VFR CONDITIONS POSSIBLE OR SHORT TERM
PERIODS OF IFR CONDITIONS POSSIBLE THE OVER THE NEXT HOUR.
PREV DISCUSSION... /ISSUED 232 PM EDT FRI JUL 26 2013/
DISCUSSION...
A TIGHT MOISTURE GRADIENT WAS IN PLACE ACROSS THE EAST COAST THIS
AFTERNOON WITH A PWAT AROUND 2 INCHES IN PALM BEACH COUNTY TO 1.5
INCHES ACROSS SOUTHEAST MIAMI-DADE COUNTY. DEEP WEST TO WEST
NORTHWEST FLOW WILL CONTINUE AS A LOW LEVEL TROUGH PUSHES
SOUTHEAST. A BOUNDARY WAS EVIDENT ON SATELLITE IMAGERY FROM THE
GULF WATERS ACROSS MAINLAND MONROE AND MIAMI-DADE COUNTY. THIS
BOUNDARY WAS SLIDING SLOWLY TO THE SOUTH. A COUPLE SHOWERS HAVE
DEVELOPED ALONG IT IN THE GULF. DRY AIR IN THE LOW/MID LEVELS AND
WARM TEMPERATURES ALOFT SHOULD LIMIT OVER THUNDERSTORM ACTIVITY
THIS AFTERNOON. HOWEVER...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE STILL FORECAST FOR THIS AFTERNOON.
SHOWER AND THUNDERSTORM ACTIVITY IS FORECAST TO DIMINISH IN THE
EVENING WITH LOSS OF DAYTIME HEATING. THE LOW LEVEL TROUGH WILL LIFT
NORTHEAST AS AN UPPER TROUGH DIGS INTO THE SOUTHEAST ON SATURDAY.
THE SUBTROPICAL RIDGE WILL BUILD SLOWLY WESTWARD...BUT WILL REMAIN
JUST OFF THE EAST COAST ON SATURDAY. HOWEVER...WINDS NEAR THE
COAST ARE FORECAST TO SHIFT TO THE SOUTH AROUND THE EDGE OF THE
RIDGE...AT THE SURFACE AND ALOFT...AND A WEAK EAST COAST SEA
BREEZE MAY DEVELOP IN THE AFTERNOON. PWATS ARE FORECAST TO
INCREASE TO 1.8-2 INCHES ACROSS THE REGION...SO SCATTERED SHOWERS
AND THUNDERSTORMS ARE FORECAST FOR THE INTERIOR AND EAST.
THE SUBTROPICAL RIDGE WILL THEN BUILD INTO THE REGION ON SUNDAY AND
THE UPPER TROUGH WILL BEGIN TO LIFT TO THE NORTHEAST. SO A MORE
TYPICAL PATTERN OF AFTERNOON SHOWERS AND THUNDERSTORMS ALONG THE SEA
BREEZE BOUNDARIES ARE FORECAST. THE RIDGE WILL CONTINUE TO BUILD
INTO THE REGION ON MONDAY WITH DEEPER EASTERLY FLOW. SO AFTERNOON
SHOWERS AND THUNDERSTORMS WILL CONCENTRATE ACROSS THE INTERIOR AND
TOWARDS THE GULF COAST. THIS PATTERN IS FORECAST TO CONTINUE THROUGH
THE WEEK. TEMPERATURES ARE FORECAST TO REMAIN NEAR NORMAL THROUGH
THE PERIOD.
AS FOR DORIAN...THE OFFICIAL FORECAST FROM THE NATIONAL HURRICANE
CENTER KEEPS THE SYSTEM AS A TROPICAL STORM WITH THE STORM MOVING
TOWARDS CUBA ON DAY 5. IT IS STILL WAY TOO EARLY TO SAY IF THE
STORM WILL HAVE ANY IMPACT ON SOUTH FLORIDA WEATHER. HOWEVER...IT
IS A GOOD TIME TO REVIEW SUPPLIES AND MAKE SURE YOU HAVE A
HURRICANE PLAN IN PLACE...ESPECIALLY AS WE ENTER THE ACTIVE
PERIOD OF THE HURRICANE SEASON OVER THE NEXT FEW WEEKS.
AVIATION...
A WEAK TROUGH OF LOW PRESSURE IS MOVING ACROSS SOUTH FLORIDA THIS
AFTERNOON. THIS HAS CAUSED A FEW WEAK SHOWERS TO DEVELOP. HOWEVER,
THERE IS A LACK OF INSTABILITY IN THE UPPER ATMOSPHERE, SO THEY
HAVE HAD A HARD TIME STAYING TOGETHER. GIVEN THIS, HAVE KEPT ANY
MENTION OF SHRA OR TSRA OUT OF THE TAFS THIS AFTERNOON, ESPECIALLY
SINCE ANY CONVECTION THAT IS ABLE TO DEVELOP WILL MAINLY ISOLATED
IN NATURE. SO, EXPECT MAINLY VFR CONDITIONS ACROSS SOUTH FLORIDA,
WITH BRIEF MVFR POSSIBLE THIS AFTERNOON DUE TO CIGS AROUND 3000FT.
TONIGHT SHOULD SEE SKIES CLEAR ACROSS MOST OF SOUTH FLORIDA. WINDS
WILL REMAIN WESTERLY THIS AFTERNOON, BECOMING MOSTLY LIGHT AND
VARIABLE TONIGHT. TOMORROW, HIGH PRESSURE BEGINS TO BUILD IN FROM
THE EAST. THIS WILL TURN THE WINDS MORE SOUTHERLY AROUND 10 KTS.
MARINE...
THE WINDS WILL SLOWLY SWING TO A SOUTHERLY DIRECTION THIS WEEKEND
WITH SPEEDS DECREASING TO 10 KNOTS OR LESS. THIS WILL KEEP THE
SEAS AT 2 FEET OR LESS IN BOTH THE ATLANTIC AND GULF WATERS
THROUGH THE WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD FOR ALL
SOUTH FLORIDA WATERS THROUGH THIS WEEKEND OUTSIDE OF ANY SHOWERS
AND THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 76 90 / 30 60 20 30
FORT LAUDERDALE 77 89 78 89 / 50 60 20 20
MIAMI 77 90 78 91 / 50 60 20 20
NAPLES 76 89 74 89 / 20 30 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
753 PM EDT FRI JUL 26 2013
.UPDATE...POPS/WEATHER UPDATED TO REFLECT THE NUMEROUS-WIDESPREAD
ACTIVITY WHICH DEVELOPED INTO BROWARD COUNTY AND NOW MOVING INTO
MIAMI-DADE WHILE WEAKENING. ADDITIONAL CONVECTION IS MOVING SOUTH
INTO THE LAKE OKEECHOBEE REGION FROM CENTRAL FL. HRRR SHOWS THIS
ACTIVITY DIMINISHING WITH LOSS OF HEATING. WILL WATCH THIS
CLOSELY, BUT FOR NOW DO EXPECT ONLY ISOLATED ACTIVITY EAST COAST
OVERNIGHT. /GREGORIA
&&
.AVIATION...WITH THE EXCEPTION OF TERMINAL KPBI...REMAINING EAST
COAST TERMINALS ASSIGNED VCTS OR TSRA FOR THE NEXT HOUR OR TWO.
HOWEVER THE LINE OF SHOWERS AND THUNDERSTORMS THAT PROMPTED THIS
IS BEGINNING TO DISSIPATE WITH THE MOST ACTIVE THUNDERSTORMS NOW
OVER THE ADJACENT ATLANTIC WATERS. BUT LINGERING SHOWERS AND/OR A
THUNDERSTORM COULD AFFECT THE AFOREMENTIONED TERMINALS IN THE
SHORT TERM...WITH SUB-VFR CONDITIONS POSSIBLE OR SHORT TERM
PERIODS OF IFR CONDITIONS POSSIBLE THE OVER THE NEXT HOUR.
&&
.PREV DISCUSSION... /ISSUED 232 PM EDT FRI JUL 26 2013/
DISCUSSION...
A TIGHT MOISTURE GRADIENT WAS IN PLACE ACROSS THE EAST COAST THIS
AFTERNOON WITH A PWAT AROUND 2 INCHES IN PALM BEACH COUNTY TO 1.5
INCHES ACROSS SOUTHEAST MIAMI-DADE COUNTY. DEEP WEST TO WEST
NORTHWEST FLOW WILL CONTINUE AS A LOW LEVEL TROUGH PUSHES
SOUTHEAST. A BOUNDARY WAS EVIDENT ON SATELLITE IMAGERY FROM THE
GULF WATERS ACROSS MAINLAND MONROE AND MIAMI-DADE COUNTY. THIS
BOUNDARY WAS SLIDING SLOWLY TO THE SOUTH. A COUPLE SHOWERS HAVE
DEVELOPED ALONG IT IN THE GULF. DRY AIR IN THE LOW/MID LEVELS AND
WARM TEMPERATURES ALOFT SHOULD LIMIT OVER THUNDERSTORM ACTIVITY
THIS AFTERNOON. HOWEVER...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE STILL FORECAST FOR THIS AFTERNOON.
SHOWER AND THUNDERSTORM ACTIVITY IS FORECAST TO DIMINISH IN THE
EVENING WITH LOSS OF DAYTIME HEATING. THE LOW LEVEL TROUGH WILL LIFT
NORTHEAST AS AN UPPER TROUGH DIGS INTO THE SOUTHEAST ON SATURDAY.
THE SUBTROPICAL RIDGE WILL BUILD SLOWLY WESTWARD...BUT WILL REMAIN
JUST OFF THE EAST COAST ON SATURDAY. HOWEVER...WINDS NEAR THE
COAST ARE FORECAST TO SHIFT TO THE SOUTH AROUND THE EDGE OF THE
RIDGE...AT THE SURFACE AND ALOFT...AND A WEAK EAST COAST SEA
BREEZE MAY DEVELOP IN THE AFTERNOON. PWATS ARE FORECAST TO
INCREASE TO 1.8-2 INCHES ACROSS THE REGION...SO SCATTERED SHOWERS
AND THUNDERSTORMS ARE FORECAST FOR THE INTERIOR AND EAST.
THE SUBTROPICAL RIDGE WILL THEN BUILD INTO THE REGION ON SUNDAY AND
THE UPPER TROUGH WILL BEGIN TO LIFT TO THE NORTHEAST. SO A MORE
TYPICAL PATTERN OF AFTERNOON SHOWERS AND THUNDERSTORMS ALONG THE SEA
BREEZE BOUNDARIES ARE FORECAST. THE RIDGE WILL CONTINUE TO BUILD
INTO THE REGION ON MONDAY WITH DEEPER EASTERLY FLOW. SO AFTERNOON
SHOWERS AND THUNDERSTORMS WILL CONCENTRATE ACROSS THE INTERIOR AND
TOWARDS THE GULF COAST. THIS PATTERN IS FORECAST TO CONTINUE THROUGH
THE WEEK. TEMPERATURES ARE FORECAST TO REMAIN NEAR NORMAL THROUGH
THE PERIOD.
AS FOR DORIAN...THE OFFICIAL FORECAST FROM THE NATIONAL HURRICANE
CENTER KEEPS THE SYSTEM AS A TROPICAL STORM WITH THE STORM MOVING
TOWARDS CUBA ON DAY 5. IT IS STILL WAY TOO EARLY TO SAY IF THE
STORM WILL HAVE ANY IMPACT ON SOUTH FLORIDA WEATHER. HOWEVER...IT
IS A GOOD TIME TO REVIEW SUPPLIES AND MAKE SURE YOU HAVE A
HURRICANE PLAN IN PLACE...ESPECIALLY AS WE ENTER THE ACTIVE
PERIOD OF THE HURRICANE SEASON OVER THE NEXT FEW WEEKS.
AVIATION...
A WEAK TROUGH OF LOW PRESSURE IS MOVING ACROSS SOUTH FLORIDA THIS
AFTERNOON. THIS HAS CAUSED A FEW WEAK SHOWERS TO DEVELOP. HOWEVER,
THERE IS A LACK OF INSTABILITY IN THE UPPER ATMOSPHERE, SO THEY
HAVE HAD A HARD TIME STAYING TOGETHER. GIVEN THIS, HAVE KEPT ANY
MENTION OF SHRA OR TSRA OUT OF THE TAFS THIS AFTERNOON, ESPECIALLY
SINCE ANY CONVECTION THAT IS ABLE TO DEVELOP WILL MAINLY ISOLATED
IN NATURE. SO, EXPECT MAINLY VFR CONDITIONS ACROSS SOUTH FLORIDA,
WITH BRIEF MVFR POSSIBLE THIS AFTERNOON DUE TO CIGS AROUND 3000FT.
TONIGHT SHOULD SEE SKIES CLEAR ACROSS MOST OF SOUTH FLORIDA. WINDS
WILL REMAIN WESTERLY THIS AFTERNOON, BECOMING MOSTLY LIGHT AND
VARIABLE TONIGHT. TOMORROW, HIGH PRESSURE BEGINS TO BUILD IN FROM
THE EAST. THIS WILL TURN THE WINDS MORE SOUTHERLY AROUND 10 KTS.
MARINE...
THE WINDS WILL SLOWLY SWING TO A SOUTHERLY DIRECTION THIS WEEKEND
WITH SPEEDS DECREASING TO 10 KNOTS OR LESS. THIS WILL KEEP THE
SEAS AT 2 FEET OR LESS IN BOTH THE ATLANTIC AND GULF WATERS
THROUGH THE WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD FOR ALL
SOUTH FLORIDA WATERS THROUGH THIS WEEKEND OUTSIDE OF ANY SHOWERS
AND THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 76 90 / 50 50 20 30
FORT LAUDERDALE 77 89 78 89 / 80 40 20 20
MIAMI 77 90 78 91 / 50 40 20 20
NAPLES 76 89 74 89 / 20 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
325 AM EDT THU JUL 25 2013
...UPDATED FOR RIP CURRENT STATEMENT AT BOTTOM OF DISCUSSION...
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN UPPER LEVEL
PATTERN OVER THE CONUS DOMINATED BY LARGE SCALE RIDGING OVER THE
WESTERN STATES AND DOWNSTREAM TROUGHING TO THE EAST OF THE MS
VALLEY. OUR FORECAST AREA RESIDES WITHIN A REGION OF DEEP WEST TO
NORTHWEST FLOW TOWARD THE SOUTHERN PERIPHERY OF THIS EASTERN U.S.
TROUGH. OCCASIONAL WEAK IMPULSES CONTINUE TO RIDE THIS FLOW DOWN
INTO THE SOUTHEASTERN STATES AND ENHANCE ROUNDS OF SCT CONVECTION
OFF THE NORTHEAST GULF OF MEXICO. ONE ROUND OF LATE EVENING SHOWERS
CAME ASHORE FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST. NOW
THERE IS IMPRESSIVE MODEL AGREEMENT AMONG PARAMETRIZED AND
CONVECTION ALLOWING MEMBERS ALIKE IN A MORE ROBUST ROUND OF
CONVECTION DEVELOPING AND MOVING ASHORE IN THE VICINITY OF TAMPA BAY
/ I-4 CORRIDOR AND NORTHWARD PASCO/HERNANDO/CITRUS COUNTIES FROM NOW
THROUGH DAWN. WITH A NEW IMPULSE APPROACHING THE NE GULF AND THE
VICINITY FOCUS OF A SURFACE TROUGH NEAR THE FLORIDA BIG BEND...IT IS
HARD TO DISAGREE WITH THIS MODEL CONSENSUS. HAVE RAMPED POPS UP FROM
TAMPA BAY / I-4 CORRIDOR NORTHWARD...ESPECIALLY AFTER 09-10Z. HRRR
AND LOCAL HI-RES WRFARW MEMBERS SHOW THE UPPER SUPPORT ALLOWING THIS
ACTIVITY TO PENETRATE QUICKLY INLAND AND WILL FOLLOW SUIT IN THE
FORECAST GRIDS. THIS IS A BIT DIFFERENT FROM THE CLIMO WESTERLY
NOCTURNAL SHOWERS WHICH ARE FORCED MAINLY FROM LOW LEVEL
INSTABILITY...AND GENERALLY FADE QUICKLY IN THE PRE-DAWN HOURS AFTER
REACHING SHORE.
THIS IS NOT A VERY CLIMATOLOGICAL SITUATION FOR LATE JULY...AND IT
THROWS SOME UNCERTAINTY INTO THE FORECAST. HOWEVER...AS MENTIONED
ABOVE...IT IS DIFFICULT TO IGNORE THE MODEL CONSENSUS...ESPECIALLY
SINCE ALL MEMBERS SEEM TO HAVE INITIALIZED THE MAIN PLAYING
INFLUENCES WELL THIS MORNING. THIS BAND OF HIGHER POPS FROM
HILLSBOROUGH/POLK COUNTIES NORTHWARD WILL CONTINUE THROUGH AT LEAST
MID-MORNING. THEREAFTER THE IMPULSE PASSES AND WE "SHOULD"
TRANSITION TO A MORE SEA-BREEZE/WEST FLOW DOMINATED SHOWER PATTERN
BY EARLY AFTERNOON. HOWEVER THE PRESENCE OF THE EARLY MORNING
SHOWERS/STORMS WILL ALSO INFLUENCE OUR HEATING AND DIURNAL FLOW
PATTERNS...THROWING MORE UNCERTAINLY INTO THE AFTERNOON FORECAST.
WILL DO OUR BEST EARLY THIS MORNING TO SORT ALL THIS OUT.
&&
.SHORT TERM (TODAY THROUGH SATURDAY)...
TODAY...THE MORNING FORECAST IS DETAILED IN THE SYNOPSIS ABOVE AND
WILL NOT REPEAT HERE. THE MORNING CONVECTION WILL DISRUPT THE FLOW
PATTERNS SOMEWHAT...BUT WILL ASSUME WE RECOVER EVENTUALLY AND END UP
WITH A MORE TYPICAL DISTRIBUTION OF MAINLY INLAND SHOWERS/STORMS
ASSOCIATED WITH WESTERLY FLOW FOR THE LATER PORTION OF THE DAY.
FAIRLY TIGHT GRADIENT WILL KEEP A STEADY ONSHORE FLOW AND CHOPPY
BREAKING SURF GOING ALONG OUR COASTS FOR ANOTHER DAY. EXTENDING THE
MODERATE RISK OF RIP CURRENTS THROUGH THIS EVENING FOR
PINELLAS...HILLSBOROUGH...MANATEE...AND SARASOTA COUNTIES.
TONIGHT...UPPER TROUGH AXIS WILL BEGIN TO SHIFT EAST...BUT STILL
KEEP OUR REGION UNDERNEATH AT LEAST A MINIMAL DEGREE OF CYCLONIC
FLOW. POTENTIALLY OF BIGGER INFLUENCE WILL BE A SOUTHWARD SHIFT OF
THE SURFACE TROUGH CURRENTLY NEAR THE I-10 CORRIDOR. THIS SHIFT
SOUTH IS SHOWN BY MANY OF THE ENSEMBLE NWP MEMBERS...BRINGING THE
LOW LEVEL FOCUS/WIND CONVERGENCE AXIS TO NEAR TAMPA BAY / I-4
CORRIDOR BY THE LATE NIGHT HOURS. WITH THIS IN MIND WOULD EXPECT YET
ANOTHER RESURGENCE OF NOCTURNAL SHOWERS (POSSIBLY MORE CONCENTRATED
THAN NORMAL) MOVING ASHORE FROM THE GULF AND MAKING SOME PROGRESS
INLAND. THE AXIS OF BEST RAIN CHANCES LOOKS TO BE FOCUSED A LITTLE
MORE SOUTH THAN THIS MORNING AND WILL SHOW BEST RAIN CHANCES
CENTERED FROM PASCO TO PINELLAS/HILLSBOROUGH AND SOUTH TO MANATEE
COUNTY BETWEEN SAY 09-15Z. THIS FORECAST REPRESENTS A BEST GUESS FOR
THE LOCATION OF THE CONVERGENT AXIS FOR ENHANCED LIFT BASED ON MODEL
CONSENSUS.
FRIDAY/FRIDAY NIGHT...HEIGHTS WILL FINALLY RIDGE NORTHWARD FROM THE
CENTRAL GULF OVER THE FL PENINSULA IN RESPONSE TO A SIGNIFICANT
SHORTWAVE AND ASSOCIATED HEIGHT FALLS DROPPING SOUTHWARD THROUGH THE
MID/LOWER MS VALLEY. AFTER THE MORNING SHOWER ACTIVITY FADES...THERE
IS HIGHER CONFIDENCE IN A MORE TYPICAL SEA-BREEZE INDUCED CONVECTIVE
PATTERN FOR THE SECOND HALF OF THE DAY. THE GRADIENT WILL BE WEAKER
BY THIS TIME...BUT STILL HAVE AT LEAST A MINIMAL WESTERLY SYNOPTIC
PUSH. THEREFORE...BY LATE IN THE AFTERNOON...MUCH OF THE CONVECTION
SHOULD BE PUSHED INLAND FROM THE I-75 CORRIDOR. FRIDAY NIGHT THE LOW
LEVEL GRADIENT LOOKS TO REALLY COLLAPSE...POTENTIALLY ALLOWING FOR A
WEAK LAND-BREEZE TO DEVELOP AFTER MIDNIGHT. EVENING CONVECTION OVER
THE INTERIOR SHOULD FADE BY 03-04Z...AND THEN WILL WATCH SOME
ISOLATED CELLS REDEVELOP JUST OFFSHORE ALONG THE DEVELOPING
LAND-BREEZE AFTER 09Z.
SATURDAY...VERY LIGHT GRADIENT IN PLACE WILL ALLOW DEFINED EAST
COAST AND WEST COAST SEA-BREEZES. WILL LIKELY SEE A SCATTERING OF
SHOWERS ALONG AND INSIDE OF THE I-75 CORRIDOR DURING THE LATE
MORNING AND EARLY AFTERNOON...WITH THE ACTIVITY THEREAFTER PUSHING
INLAND. MODELS ARE IN AGREEMENT IN A CLASSIC EAST AND WEST
SEA-BREEZE COLLISION ALONG THE SPINE OF THE PENINSULA LATE SATURDAY
AFTERNOON. THEREFORE IT MAY BE AN ACTIVE LATE AFTERNOON AND
ESPECIALLY EVENING OVER THE INTERIOR ZONES. ON THE OTHER
HAND...AFTER MIDDAY...MOST OF THE COAST SHOULD SEE RAIN CHANCES
FALL QUICKLY WITH A MOSTLY SUNNY AND QUIET AFTERNOON/EARLY EVENING
CURRENTLY IN THE FORECAST.
&&
.LONG TERM (SUNDAY THROUGH NEXT WEDNESDAY)...
THE PERIOD BEGINS WITH AN UPPER LOW OVER THE GREAT LAKES TROUGHING
SOUTH TO THE GULF COAST AND SE U.S. WHILE DEEP LAYER MEAN RIDGING
FROM THE OPEN ATLANTIC EXTENDS ACROSS THE BAHAMAS AND CUBA. DURING
THE FIRST PART OF NEXT WEEK THE UPPER LOW ROTATES ACROSS THE GREAT
LAKES INTO SE CANADA WITH THE TROUGHING LIFTING NORTH OF THE REGION.
THIS ALLOWS THE DEEP LAYER MEAN RIDGING TO BUILD IN ACROSS THE GULF
AS IT SHIFTS NORTH OVER FL. FOR THE VERY LAST DAY THE 25/00Z GFS HAS
WHAT IS CURRENTLY TROPICAL STORM DORIAN EAST OF THE BAHAMAS. THE
ECMWF FOR 25/00Z HAS A WEAK LOW OVER THE BAHAMAS.
AS THE TROUGHING MOVES AWAY AND THE RIDGE SLIDES ACROSS THE AREA
THERE WILL BE A SLIGHT DRYING TREND...WITH POPS GOING FROM 40-50
PERCENT TO 30-40 PERCENT FOR THE AFTERNOONS. LATE MORNINGS AND EARLY
EVENINGS WILL SEE ISOLATED POPS. WESTERLY LOW LEVEL FLOW GRADUALLY
BACKS THROUGH THE SOUTH TO SOUTHEASTERLY...AND RELAXED ENOUGH TO
PERMIT AFTERNOON SEA BREEZES TO FORM.
&&
.AVIATION...
PREVAILING VFR. A MIXTURE OF SHRA/TSRA IS EXPECTED TO IMPACT THE
NORTHERN TERMINALS/ SRQ NORTHWARD/ DURING THE MORNING HOURS BUT WILL
HOLD THE TAFS AT VCNTY FOR NOW. SOUTHERN TERMINALS...PGD/FMY/RSW
COULD SEE SOME VCSH FORM LATER IN THE MORNING. A CONTINUED WESTERLY
FLOW WILL PUSH ALL CONVECTION EAST OF ALL THE TERMINALS DURING THE
AFTERNOON. THERE COULD BE SOME OCNL BKN CIGS IN THE MVFR RANGE...TOO
LIMITED FOR TAF INCLUSION.
&&
.MARINE...
MODERATE WESTERLY FLOW WILL CONTINUE ACROSS THE EASTERN GULF OF
MEXICO BETWEEN THE SUBTROPICAL RIDGE AXIS TO THE SOUTH OF THE
FLORIDA PENINSULA. WINDS WILL AT TIMES APPROACH CAUTIONARY LEVELS
TODAY...AND THEN BEGIN TO DIMINISH OVERNIGHT AND FRIDAY AS THE
SURFACE TROUGH SINKS SOUTH AND WEAKENS THE LOCAL GRADIENT. THE WEAK
GRADIENT WILL LINGER THROUGH THE WEEKEND KEEPING WINDS AND SEAS LOW
AND ALLOWING THE RETURN OF AFTERNOON SEA-BREEZES. THE SUBTROPICAL
RIDGE AXIS LOOKS TO BUILD NORTH OVER THE EASTERN GULF OF MEXICO
DURING THE EARLY PORTION OF NEXT WEEK KEEPING WINDS AND SEAS LOW
THROUGH THE END OF THE FORECAST PERIOD.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO REMAIN WELL ABOVE CRITICAL
LEVELS THROUGH THE NEXT SEVERAL DAY. HOWEVER...ELEVATED FLOW ALOFT
WILL RESULT IN HIGH DISPERSION INDICES TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 78 92 78 / 50 40 40 10
FMY 91 77 90 77 / 20 20 30 20
GIF 90 75 94 74 / 50 30 50 30
SRQ 89 78 91 78 / 30 40 40 20
BKV 90 72 93 72 / 50 30 40 20
SPG 90 79 91 79 / 50 40 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THIS EVENING FOR HILLSBOROUGH-
MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1235 AM EDT THU JUL 25 2013
...UPDATED TO DISCUSS HIGHER CONVECTIVE POTENTIAL THIS MORNING...
.UPDATE...
OCCASIONAL WEAK IMPULSES CONTINUE TO RIDE THE FLOW DOWN THE BACKSIDE
OF AN EASTERN UNITED STATES UPPER TROUGH INTO THE SOUTHEASTERN
STATES AND ENHANCE ROUNDS OF SCT CONVECTION OFF THE NORTHEAST GULF
OF MEXICO. ONE ROUND OF LATE EVENING SHOWERS CAME ASHORE FROM TAMPA
BAY NORTHWARD ALONG THE NATURE COAST...AND NOW THERE IS IMPRESSIVE
MODEL AGREEMENT AMONG PARAMETRIZED AND CONVECTION ALLOWING MEMBERS
ALIKE IN A MORE ROBUST ROUND OF CONVECTION DEVELOPING AND MOVING
ASHORE IN THE VICINITY OF THE I-4 CORRIDOR AND NORTHWARD LATE NIGHT
TOWARD DAWN. WITH A NEW IMPULSE APPROACHING THE NE GULF IN THE NEXT
SEVERAL HOURS AND THE VICINITY FOCUS OF A SURFACE TROUGH NEAR THE
FLORIDA BIG BEND...IT IS HARD TO DISAGREE WITH THIS MODEL CONSENSUS.
HAVE RAMPED POPS UP FROM TAMPA BAY / I-4 CORRIDOR NORTHWARD...
ESPECIALLY AFTER 09Z. HRRR AND LOCAL HI-RES WRFARW MEMBERS SHOW THE
UPPER SUPPORT ALLOWING THIS ACTIVITY TO PENETRATE QUICKLY INLAND AND
WILL FOLLOW SUIT IN THE FORECAST GRIDS. THIS IS A BIT DIFFERENT FROM
THE CLIMO WESTERLY NOCTURNAL SHOWERS WHICH ARE FORCED MAINLY FROM
LOW LEVEL INSTABILITY...AND GENERALLY FADE QUICKLY IN THE PRE-DAWN
HOURS AFTER REACHING SHORE.
THIS IS NOT A VERY CLIMATOLOGICAL SITUATION FOR LATE JULY...AND IT
THROWS SOME UNCERTAINTY INTO THE FORECAST. HOWEVER...AS MENTIONED
ABOVE...IT IS DIFFICULT TO IGNORE THE MODEL CONSENSUS...ESPECIALLY
SINCE ALL MEMBERS SEEM TO HAVE INITIALIZED THE MAIN PLAYING
INFLUENCES WELL THIS MORNING. THIS BAND OF HIGHER POPS FROM
HILLSBOROUGH/POLK COUNTIES NORTHWARD WILL CONTINUE THROUGH AT LEAST
MID-MORNING. THEREAFTER THE IMPULSE PASSES AND WE "SHOULD"
TRANSITION TO A MORE SEA-BREEZE/WEST FLOW DOMINATED SHOWER
PATTERN...HOWEVER THE PRESENCE OF THE EARLY MORNING SHOWERS/STORMS
WILL ALSO INFLUENCE OUR HEATING AND DIURNAL FLOW PATTERNS...THROWING
MORE UNCERTAINLY INTO THE AFTERNOON FORECAST. WILL DO OUR BEST EARLY
THIS MORNING TO SORT ALL THIS OUT.
&&
.AVIATION...
GENERALLY VFR CONDITIONS EXPECTED...BUT CAN/T RULE OUT A SHRA
DRIFTING ONSHORE FROM KSRQ NORTHWARD THIS EVENING. BETTER CHANCES
FOR SHRA LATER TONIGHT 08/09Z AND WILL INCLUDE VCSH TO ACCOUNT
FOR THIS. SOUTH OF KSRQ...VFR CONDITIONS ARE EXPECTED THROUGH THE
OVERNIGHT HOURS. BEST CHANCE OF TSRA WILL BE EAST OF ALL TERMINALS
THURSDAY...SO WILL NOT MENTION VCTS AT ANY OF THE TAF SITES. HAVE
INCLUDED VCSH AT MOST PROBABLE TIMES AT ALL TAF SITES...BUT HIGHEST
RAIN CHANCES WILL CONTINUE TO BE FROM KSRQ NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 89 79 91 / 50 50 20 20
FMY 78 91 78 91 / 20 20 10 20
GIF 75 91 75 93 / 40 50 10 40
SRQ 80 89 79 89 / 30 30 10 20
BKV 74 90 73 93 / 50 50 20 20
SPG 81 88 82 90 / 40 40 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 6 AM EDT THURSDAY FOR HILLSBOROUGH-
MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JELSEMA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
245 PM EDT THU JUL 25 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH OVER THE EASTERN US WILL REMAIN ACROSS THE
REGION THROUGH THE WEEKEND. THIS WILL INTERACT WITH A WEAK FRONTAL
BOUNDARY TO CONTINUE THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH REMAINS OVER THE E CONUS. VORT MAX PUSHING TO OUR
EAST WITH NVA OVER THE FA CURRENTLY. QUITE DRY AIR ALOFT OVER THE
REGION AS WELL. COMBINATION OF DRY AIR ALOFT AND NVA MAY LIMIT
AREAL COVERAGE OF CONVECTION TODAY. FORECAST SOUNDINGS ALSO
INDICATE SOME LOW LEVEL CAPPING EARLY THIS AFTERNOON...BUT
INDICATE THIS COULD BE OVERCOME WITH ENOUGH HEATING AND
CONVERGENCE ALONG ANY BOUNDARIES...SUCH AS SURFACE TROUGH/SEA
BREEZE/OUTFLOWS ETC. NVA IS EXPECTED TO DIMINISH LATE TODAY. ARRAY
OF HIGH RESOLUTION MODEL OUTPUT INCONSISTENT. LATEST HRRR AND RAP
SUGGESTING MINIMAL CONVECTIVE ACTIVITY...WHILE LOCAL WRF AND 12Z
SPC WRF MORE BULLISH ON CONVECTIVE PROSPECTS. NOTHING ON RADAR AT
1730Z...BUT STILL THINK THERE IS THE PREMISE FOR AT LEAST SLIGHT
CHANCE POPS LATE TODAY AND THIS EVENING. ANY THUNDERSTORMS THAT DO
FORM WILL HAVE A HAIL OR WIND GUST THREAT DUE TO DRY AIR ALOFT AND
MODERATE INSTABILITIES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS WILL BE OFF THE COAST TONIGHT WITH A GRADUAL
DRYING TREND AS PRECIPITABLE WATER VALUES FALL DOWN TO BETWEEN
1.25 AND 1.50 INCHES. SUBSIDENCE IN THE WAKE OF THE DEPARTING
UPPER TROUGH ALONG WITH LESS MOISTURE SHOULD PREVENT MUCH IN THE
WAY OF NOCTURNAL CONVECTION. ONLY ISOLATED TO SCATTERED STORMS ON
FRIDAY WITH THE FORECAST AREA FALLING BETWEEN SYSTEMS.
SHORTWAVE ENERGY DIVING SOUTHWARD THROUGH THE GREAT LAKES INTO THE
WESTERN OHIO VALLEY ON SATURDAY WILL CAUSE THE 500MB FLOW TO BACK
MORE SOUTHWESTERLY ACROSS THE SOUTHEAST AND TENNESSEE VALLEY...
RESULTING IN MOISTURE INCREASING AGAIN ACROSS THE REGION.
CONVECTIVE COVERAGE WILL SHOULD BE A BIT BETTER SATURDAY AS WEAK
DISTURBANCES IN THE UPPER FLOW COULD TRIGGER CONVECTION ALTHOUGH
THE MAIN ENERGY WILL REMAIN TO THE NORTHWEST. THE INCREASED
ATMOSPHERIC MOISTURE WILL LEAD TO A BIT MORE DIURNALLY UNSTABLE
AIRMASS AND WILL CARRY HIGHER CHANCE POPS ON SATURDAY AFTERNOON
THAN FRIDAY...WITH A HIGHER POPS ACROSS THE WESTERN COUNTIES.
TEMPERATURES DURING THIS PERIOD WILL BE NEAR NORMAL WITH HIGHS IN
THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE APPEARS TO BE IN REASONABLE AGREEMENT WITH
THE OVERALL PATTERN SHOWING A GENERAL UPPER TROUGH AXIS REMAINING
JUST WEST OF THE FORECAST AREA SUN/MON WITH A SURFACE FRONTAL
BOUNDARY PUSHING INTO OR CLOSE TO THE FORECAST AREA. PRECIPITABLE
WATER VALUES RISE BACK UP TO NEAR 2 INCHES IN VICINITY OF THE
FRONTAL BOUNDARY WHICH WILL STALL OUT OVER THE AREA. THE ECMWF
BACKS THE MID LEVEL FLOW MORE ZONAL THROUGH MIDWEEK WHILE THE GFS
KEEPS A BIT OF A RESIDUAL UPPER TROUGH OVER THE FORECAST AREA.
WILL GO CLOSER TO THE ECMWF FORECAST WITH HIGH CHANCE TO LIKELY
POPS SUN/MON. ALTHOUGH UPPER FLOW BACKS MORE WESTERLY BY MID
WEEK...SHORTWAVE ENERGY MOVING THROUGH THE UPPER FLOW IS EXPECTED
TO MOVE OVER THE AREA AND SPARK DIURNAL CONVECTION WHICH MAY
LINGER INTO THE OVERNIGHT HOURS TUE THROUGH THU. TEMPERATURES
THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR DAYTIME
HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THIS AFTERNOON...WITH SCT TO BKN CU WITH
VFR BASES. SLIGHT CHANCE OF LATE DAY/EVENING CONVECTION...BUT
CHANCES TOO LOW TO INCLUDE TS MENTION IN THE TAFS AT THIS TIME.
SOME RESTRICTIONS POSSIBLE LATE TON/EARLY MON...BUT CONFIDENCE
LOW.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
139 PM EDT THU JUL 25 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH OVER THE EASTERN US WILL REMAIN ACROSS THE
REGION THROUGH THE WEEKEND. THIS WILL INTERACT WITH A WEAK FRONTAL
BOUNDARY TO CONTINUE THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPPER TROUGH REMAINS OVER THE E CONUS. VORT MAX PUSHING TO OUR
EAST WITH NVA OVER THE FA CURRENTLY. QUITE DRY AIR ALOFT OVER THE
REGION AS WELL. COMBINATION OF DRY AIR ALOFT AND NVA MAY LIMIT
AREAL COVERAGE OF CONVECTION TODAY. FORECAST SOUNDINGS ALSO
INDICATE SOME LOW LEVEL CAPPING EARLY THIS AFTERNOON...BUT
INDICATE THIS COULD BE OVERCOME WITH ENOUGH HEATING AND
CONVERGENCE ALONG ANY BOUNDARIES...SUCH AS SURFACE TROUGH/SEA
BREEZE/OUTFLOWS ETC. NVA IS EXPECTED TO DIMINISH LATE TODAY. ARRAY
OF HIGH RESOLUTION MODEL OUTPUT INCONSISTENT. LATEST HRRR AND RAP
SUGGESTING MINIMAL CONVECTIVE ACTIVITY...WHILE LOCAL WRF AND 12Z
SPC WRF MORE BULLISH ON CONVECTIVE PROSPECTS. NOTHING ON RADAR AT
1730Z...BUT STILL THINK THERE IS THE PREMISE FOR AT LEAST SLIGHT
CHANCE POPS LATE TODAY AND THIS EVENING. ANY THUNDERSTORMS THAT DO
FORM WILL HAVE A HAIL OR WIND GUST THREAT DUE TO DRY AIR ALOFT AND
MODERATE INSTABILITIES.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS EXPECTED TO BE EAST OF THE FORECAST AREA BY
TONIGHT WITH A GRADUAL DRYING TREND AS PRECIPITABLE WATER VALUES
FALL DOWN TO BETWEEN 1.25 AND 1.50 INCHES. SUBSIDENCE IN THE WAKE
OF THE DEPARTING UPPER TROUGH ALONG WITH LESS MOISTURE SHOULD
PREVENT MUCH NOCTURNAL CONVECTION AND ONLY ISOLATED TO SCATTERED
STORMS ON FRIDAY WITH THE FORECAST AREA FALLING BETWEEN SYSTEMS.
SHORTWAVE ENERGY DIVING SOUTHWARD THROUGH THE GREAT LAKES INTO THE
WESTERN OHIO VALLEY ON SATURDAY WILL CAUSE THE 500MB FLOW TO BACK
MORE SOUTHWESTERLY ACROSS THE SOUTHEAST AND TENNESSEE
VALLEY...RESULTING IN MOISTURE INCREASING AGAIN ACROSS THE REGION.
CONVECTIVE COVERAGE WILL SHOULD BE A BIT BETTER SATURDAY AS WEAK
DISTURBANCES IN THE UPPER FLOW COULD TRIGGER CONVECTION ALTHOUGH
THE MAIN ENERGY WILL REMAIN TO THE NORTHWEST. THE INCREASED
ATMOSPHERIC MOISTURE WILL LEAD TO A BIT MORE DIURNALLY UNSTABLE
AIRMASS AND WILL CARRY HIGHER CHANCE POPS ON SATURDAY AFTERNOON
THAN FRIDAY...ALSO HAVING A GRADIENT FROM WEST TO EAST.
TEMPERATURES DURING THIS PERIOD WILL BE NEAR NORMAL WITH HIGHS IN
THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LITTLE CHANGE MADE DURING THIS PERIOD.
MEDIUM RANGE GUIDANCE APPEARS TO BE IN REASONABLE AGREEMENT WITH
THE OVERALL PATTERN SHOWING A GENERAL UPPER TROUGH AXIS REMAINING
JUST WEST OF THE FORECAST AREA SUN/MON WITH A SURFACE FRONTAL
BOUNDARY PUSHING INTO OR CLOSE TO THE FORECAST AREA. PRECIPITABLE
WATER VALUES RISE BACK UP TO NEAR 2 INCHES IN VICINITY OF THE
FRONTAL BOUNDARY WHICH WILL STALL OUT OVER THE AREA. THE ECMWF
BACKS THE MID LEVEL FLOW MORE ZONAL THROUGH MIDWEEK WHILE THE GFS
KEEPS A BIT OF A RESIDUAL UPPER TROUGH OVER THE FORECAST AREA.
WILL CONTINUE WITH PREVIOUS FORECAST OF HIGH CHANCE TO LIKELY POPS
SUN/MON. ALTHOUGH UPPER FLOW BACKS MORE WESTERLY BY MID
WEEK...SHORTWAVE ENERGY MOVING THROUGH THE UPPER FLOW IS EXPECTED
TO MOVE OVER THE AREA AND SPARK DIURNAL CONVECTION WHICH MAY
LINGER INTO THE OVERNIGHT HOURS TUE/WED. TEMPERATURES THROUGH THE
LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR DAYTIME HIGHS WITH
OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THIS AFTERNOON...WITH SCT TO BKN CU WITH
VFR BASES. SLIGHT CHANCE OF LATE DAY/EVENING CONVECTION...BUT
CHANCES TOO LOW TO INCLUDE TS MENTION IN THE TAFS AT THIS TIME.
SOME RESTRICTIONS POSSIBLE LATE TON/EARLY MON...BUT CONFIDENCE
LOW.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
212 PM MDT THU JUL 25 2013
.DISCUSSION...EASTERN IDAHO REMAINS IN NOSE OF UPPER RIDGE OVER
GREAT BASIN TODAY. RADAR/SAT SHOW CONVECTION BUBBLING OVER HIGHER
ELEVATION AREAS PARTICULARLY CENTRAL MOUNTAINS AND SOUTHERN
HIGHLANDS IN WEAKLY UNSTABLE AREAS. HRRR PLACES BEST THREAT OF
CONVECTION OVER CENTRAL MOUNTAINS AND ALONG DIVIDE 21-03Z THOUGH
RADAR SHOWS CURRENT RETURNS OVER SOUTHERN HIGHLANDS. AIRMASS
AGAIN DESTABILIZES AGAIN ON FRIDAY WHILE UPPER LOW OVER BC CANADA
CONTINUES TO DROP TOWARD THE PACNW STATES. MOISTURE PULLED NORTH
FROM NEVADA FRIDAY INTO SATURDAY AHEAD OF FRONTAL BOUNDARY
DEVELOPING ACROSS THE REGION. BOTH GFS AND NAM HINTING AT
CONVECTION CONTINUING OVERNIGHT FRIDAY NIGHT SO MAINTAINED POPS
HIGH ENOUGH TO GET ISOLATED MENTION. UNSTABLE AIRMASS AHEAD OF
FRONTAL BOUNDARY IN PLACE SATURDAY WITH NAM SHOWING LIFTEDS OF -2
TO -4 AND MUCAPE CLOSE TO 1000 J/KG. FRONTAL BOUNDARY SHIFTS
SLIGHTLY EAST FOR SUNDAY WITH DRIER AIR PUSHING BACK INTO THE
CENTRAL MOUNTAINS. THUS EASTERN/SOUTHERN HIGHLANDS WOULD BE BEST
THREAT LOCATION FOR CONTINUED CONVECTION INTO SUNDAY. UPPER RIDGE
TRIES TO NOSE BACK INTO THE REGION MONDAY THRUOGH REMAINDER OF
FCST PERIOD. CANT COMPLETELY RULE OUT CONVECTION DAY TO DAY UNDER
INFLUENCE OF SOUTHWEST FLOW WITH RIDGE AXIS TO THE EAST AND TROUGH
TO THE WEST. THUS MAINTAINED WEAK POPS MAINLY HIGHER ELEVATIONS
FOR EACH DAY. DMH
&&
.AVIATION...VFR CONDITIONS LIKELY TO CONTINUE TODAY/FRIDAY. AREA OF
CONVECTION CURRENTLY DEVELOPING NORTH OF KSUN AND ALSO ACROSS THE
SRN HIGHLANDS. CLOUD DRIFT INDICATES THAT KSUN MY SEE A TSTM IMPACT
LATER THIS EVE SO HAVE CONTINUED MENTION OF VCTS THIS EVENING. WILL
LIKELY SEE SIMILAR ACTIVITY FRIDAY AFTERNOON. HUSTON
&&
.FIRE WEATHER...UPPER RIDGE REMAINS POSITIONED OVER THE GREAT BASIN
WITH LIMITED UPPER MOISTURE STREAMING THROUGH IDAHO. VISIBLE
SATELLITE IMAGERY WAS SHOWING THINGS DESTABILIZING MODESTLY THIS
AFTERNOON WITH EXPECTATION THAT ISOLATED CONVECTION WILL DEVELOP
OVER THE CNTRL AND SRN MOUNTAINS LATE THIS AFTN/EVE THEN DISSIPATE
OVERNIGHT. UPPER TROUGH OFF THE NW BRITISH COLUMBIA COAST WILL
MIGRATE EAST FRIDAY THROUGH SUNDAY. EXPECT ENOUGH MOISTURE AND
INSTABILITY ACROSS THE CNTRL MOUNTAINS TO SUPPORT THUNDERSTORM
ACTIVITY ONCE AGAIN FRIDAY ALTHOUGH GFS/NAM AT ODDS IN THIS REGARD.
SURFACE FRONT ASSOCIATED WITH ADVANCING TROUGH WILL BLEED INTO THE
CNTRL MOUNTAINS SATURDAY AFTERNOON PRODUCING GUSTY WINDS. AFTER
COORD WITH LOCAL DISPATCH AGENCIES...WILL HOIST A FIRE WEATHER WATCH
FOR THE CNTRL IDAHO MOUNTAIN ZONES 422/475/476 FOR GUSTY WINDS AND
LOW RH SATURDAY AFTERNOON/EVE. FRONT GATHERS ITSELF SATURDAY NIGHT
ALONG A LINE FROM DUBOIS-ARCO-JEROME AND THEN MAKES A FINAL PUSH
THROUGH THE SNAKE PLAIN/SE HIGHLANDS SOMETIME SUNDAY. MAY NEED TO
ISSUE HEADLINES FOR EASTERN MAGIC VALLEY/SNAKE PLAIN WITH INITIAL
PUSH SATURDAY AFTERNOON CONTINUING INTO SUNDAY...BUT CONFIDENCE
AT THIS TIME A BIT LOW SO WILL HOLD OFF. A GOOD PORTION OF THE
UPPER LOW CONTINUES ITS EWRD TREK ACROSS CANADA SUNDAY/MONDAY
WHILE A PORTION OF THE SRN EXTENT BREAKS AWAY AND DRIFTS INTO A
POSITION OFF THE NW COAST TUESDAY. THUS ANTICIPATE SLOWLY
DECREASING WINDS SUNDAY/MONDAY ACROSS THE REGION AS RIDGE REBOUNDS
ACROSS THE GREAT BASIN. LOOKS AS IF WE COULD BE BACK INTO THE
STRONG SW FLOW ALOFT AND POTENTIAL THUNDERSTORM ACTIVITY AS EARLY
AS WEDNESDAY AS THE GFS IS SHOWING THE TROUGH EDGING INLAND ACROSS
WASHINGTON STATE. COMING WEEK LOOKS TO BE ACTIVE. STAY TUNED.
HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
835 PM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 834 PM CDT FRI JUL 26 2013
WEAKENING LINE OF CONVECTION HAS PROGRESSED ABOUT A THIRD OF THE
WAY ACROSS THE CWA...EXTENDING FROM LINCOLN TO WINCHESTER AT 830
PM. HAVE HAD SEVERAL REPORTS OF A QUICK HALF TO 1 INCH OF RAIN
WITH THIS BAND. FURTHER EAST...HAVE HAD SCATTERED SHOWERS MUCH OF
THE EVENING. NOT MUCH IN THE WAY OF INSTABILITY ACROSS THE EASTERN
HALF OF THE CWA...SO THE CURRENT LINE SHOULD CONTINUE TO SLOWLY
WEAKEN. HAVE UPDATED THE GRIDS ACROSS THE EAST TO MENTION ONLY
ISOLATED THUNDER WITH SCATTERED SHOWERS PREVAILING.
FRONTAL BOUNDARY WAS APPROACHING THE ILLINOIS RIVER AND SKIES
WERE QUICKLY CLEARING BEHIND IT...ALTHOUGH SOME COLD-AIR
STRATOCUMULUS CONTINUES TO DROP SOUTHWARD THROUGH IOWA. DRIER AIR
IS NOT TOO FAR BEHIND THE FRONT WITH DEW POINTS DOWN TO THE UPPER
40S IN PORTIONS OF CENTRAL IOWA. WITH THIS TYPE OF DRIER AIR
ADVECTING IN...CURRENT LOW TEMPERATURE FORECAST STILL LOOKS
REASONABLE...ALTHOUGH SOME UPDATES WERE DONE TO THE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 624 PM CDT FRI JUL 26 2013
LINE OF THUNDERSTORMS MOVING THROUGH KPIA NOW...AND SHOULD BE
CROSSING THE REMAINDER OF THE CENTRAL ILLINOIS TAF SITES IN THE
01-03Z TIME FRAME. MVFR CEILINGS HAVE BEEN ON THE INCREASE AHEAD
OF THIS LINE...WITH SOME PATCHES OF IFR ALONG AND IMMEDIATELY
BEHIND THE STORMS. THE LINE OF STORMS IS ALONG A COLD
FRONT...WHICH WILL BE THROUGH THE TAF SITES BY 06Z. SKIES EXPECTED
TO CLEAR SOME BEHIND IT...BUT HAVE LINGERED MVFR CEILINGS AT KCMI
THROUGH THE NIGHT AS THE FRONT STARTS TO SLOW DOWN A BIT.
DURING THE DAY ON SATURDAY...A STRONG UPPER LOW FOR THIS TIME OF
YEAR WILL BE DIGGING SOUTHWARD INTO NORTHERN ILLINOIS AND INDIANA.
THIS IS EXPECTED TO BRING EXTENSIVE DIURNAL CUMULUS AND PERHAPS
SOME LIGHT SHOWERS. FORECAST SOUNDINGS SHOWING THAT CEILINGS
SHOULD BE ABOVE 4000 FEET WITH THESE CLOUDS.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT FRI JUL 26 2013
SHOWERS AND STORMS WILL BE POSSIBLE THROUGH TONIGHT ALONG A COLD
FRONT...THEN AN UNSEASONABLY COOL AIR MASS WILL SETTLE INTO
ILLINOIS FOR SATURDAY AND SUNDAY. A WARMING TREND WILL BEGIN ON
MONDAY AS UPPER FLOW BECOMES MORE ZONAL FROM WEST TO EAST. ONE LOW
PRESSURE SYSTEM IS EXPECTED TO EJECT FROM THE SOUTHERN PLAINS
ACROSS SOUTHERN ILLINOIS MONDAY NIGHT AND TUESDAY. A WEAKER UPPER
TROUGH WILL SWING ACROSS NORTHERN ILLINOIS ON THURSDAY...SETTING
UP NORTHWEST FLOW ALOFT THROUGH FRIDAY.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
19Z SURFACE ANALYSIS SHOWS THE COLD FRONT APPROACHING THE
IOWA/ILLINOIS BORDER. RADAR SHOWS A NARROW LINE OF SHOWERS AND
STORMS ALONG THE FRONT IN IOWA...AND FARTHER SOUTHEAST AHEAD OF
THE FRONT IN EASTERN MISSOURI AND FAR WESTERN ILLINOIS. A BROAD
COVERAGE OF LIGHT RAIN SHOWERS EXTENDED ACROSS MUCH OF CENTRAL
ILLINOIS AND INTO WEST CENTRAL INDIANA. MOST AREAS IN CENTRAL
ILLINOIS WERE SEEING LESS THAN 0.10" OF RAIN OUT AHEAD OF THE
FRONT.
4KM NCEP AND HRRR OUTPUT INDICATE THE LINE WILL MAINTAIN SOME
INTENSITY DURING THE DAYLIGHT HOURS...BUT WEAKEN WITH SUNSET AS
THE LINE OF STORMS REACHES THE I-55 CORRIDOR. TIMING BASED ON
RADAR AND HRRR HAS THE LINE OF STORMS GENERALLY INTO INDIANA BY
08Z/3 AM. THE GFS/NAM/ECMWF/GEM ARE NOT FAR OFF FROM THAT
ASSESSMENT...SO WE HAVE UPDATED THE POPS LIKEWISE. BASICALLY,
SCATTERED COVERAGE IS EXPECTED ALONG AND AHEAD OF THE FRONT, SO
CHANCE POPS WERE USED /30-50 PCT/. SOME AREAS MAY SEE A STRONGER
UPDRAFT AND RECEIVED 0.25" RAIN IN A SHORT TIME, WHILE NEARBY
AREAS SEE LITTLE TO NO RAIN.
SATURDAY WILL FEATURE THE ARRIVAL OF A CHILLY CANADIAN AIR MASS AS
AIRFLOW BECOMES NORTH-NORTHWEST THROUGH A DEEP LAYER OF THE
ATMOSPHERE. 850MB TEMPS WILL DROP TO +6C IN OUR NORTH WITH 9-10C IN
THE SOUTH. ANY DAYTIME HEATING WILL CREATE STEEP LOW LEVEL LAPSE
RATES...WHICH WILL WORK TOGETHER WITH INCREASING BULK SHEAR AND
POSITIVE VORTICITY ADVECTION TO KICK OFF A FEW SHOWERS SATURDAY
AFTERNOON. MOST AREAS WILL PROBABLY REMAIN DRY...AND ANY RAIN THAT
DOES DEVELOP WILL NOT ADD UP TO 0.01"...SO WE WENT WITH SCATTERED
SPRINKLES FOR OUR NORTHERN COUNTIES SAT AFTN.
CLOUD COVER WILL DEVELOP QUICKLY IF ANY SUNSHINE BREAKS THROUGH
FOR ANY LENGTH OF TIME...WHICH WILL HELP TO KEEP HIGHS IN THE
70-73 DEG RANGE. WOULD NOT BE SURPRISED IF SOME LOCATIONS DO NOT
REACH 70 IF THE 6C LINE AT 850MB DOES REACH OUR COUNTIES. DRY
ADIABATIC MIXING OF 6C FROM 850MB WOULD ONLY PRODUCE A HIGH OF
66F. ANY SHOWERS WILL QUICKLY DISSIPATE WITH THE APPROACH OF
SUNSET.
RECORD OR NEAR RECORD LOWS ARE FORECAST FOR SATURDAY NIGHT.
CLEARING SKIES WILL BE A KEY COMPONENT OF THAT HAPPENING...BUT ALL
INDICATIONS ARE THAT CLOUDS WILL BE DIURNALLY DRIVEN AND SHOULD
DISSIPATE SAT EVE. LOW 50S WILL BE COMMON ACROSS THE FORECAST
AREA. RECORD LOW FOR PIA AND SPI SAT NIGHT IS 53.
SUNDAY MAY BE A CARBON COPY OF SATURDAY...WITH THE UPPER TROUGH
LINGERING ACROSS THE WESTERN GREAT LAKES AND INTO EASTERN
ILLINOIS, AND LITTLE CHANGE IN THE AIR MASS. SPOTTY SHOWERS AND
SPRINKLES WILL BE POSSIBLE...MAINLY IN THE NORTH CLOSER TO THE
COLDER AIR.
MONDAY WILL START A WARMING TREND AS THE UPPER TROUGH AXIS DEPARTS
TO THE EAST AND WESTERLY FLOW DEVELOP. THAT WILL SET THE STAGE FOR
A PROGRESSIVE LOW TO MOVE FROM THE PLAINS ACROSS SOUTHERN MISSOURI
AND SOUTHERN IL. SOME LOCALLY HEAVY RAIN WILL BE POSSIBLE LATER
MONDAY NIGHT AS THE LOW APPROACHES AND A WARM FRONT DEVELOPS
NEAR OUR SOUTHERN COUNTIES. THE MODELS HAVE TRENDED FARTHER SOUTH
WITH THE TRACK OF THE LOW THE LAST 2 MODEL RUNS...SO IT IS NOT OUT
OF THE QUESTION THAT LATER RUNS TAKE IT EVEN FARTHER SOUTH. WE
REDUCED LIKELY POPS TO CHANCE MONDAY NIGHT TO TREND DOWN...BUT
ADDED SOME LIKELY TO TUES IN OUR FAR SOUTHERN COUNTIES AS
GFS/ECMWF AGREE ON DECENT COVERAGE OF SHOWERS/STORMS DURING THE
DAY IN SOUTHERN IL RIGHT NOW. PRECIP WILL DIMINISH TUESDAY NIGHT
AS THE BULK OF THE FORCING FOR PRECIP DEPARTS TO THE EAST WITH THE
LOW.
WARMING WILL DEVELOP AHEAD OF THE LOW...AND DEWPOINTS WILL CLIMB
BACK INTO THE 60S WITH THE SYSTEM. LOCALLY HEAVY RAIN MAY DEVELOP
IN THE STRONGER STORMS...WITH RAINFALL RATES OF 1-2 INCHES PER
HOUR.
LONG TERM...WEDNESDAY THROUGH FRIDAY.
WEDNESDAY LOOKS MAINLY DRY AT THIS POINT, ALTHOUGH SOME ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE AS NORTHWEST FLOW RETURNS AND
500MB SHORTWAVES MOVE INTO THE AREA. DEWPOINTS WILL CLIMB INTO THE
UPPER 60S BY WEDNESDAY...SO MUGGY FEELING AIR WILL RETURN AS HIGHS
CLIMB INTO THE LOWER 80S. SOME MID 80S FOR HIGHS WILL BE POSSIBLE
ON THURSDAY AND FRIDAY AS 850MB TEMPS CLIMB BACK TO 14-16C. RAIN
CHANCES INCREASE MORE DRAMATICALLY ON FRIDAY PER THE GFS...WITH A
STRONGER SYSTEM DROPPING SOUTHEAST FROM THE NORTHERN PLAINS. THE
ECMWF LAGS THE GFS BY 24 HRS WITH THAT FEATURE.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
624 PM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 300 PM CDT FRI JUL 26 2013
SHOWERS AND STORMS WILL BE POSSIBLE THROUGH TONIGHT ALONG A COLD
FRONT...THEN AN UNSEASONABLY COOL AIR MASS WILL SETTLE INTO
ILLINOIS FOR SATURDAY AND SUNDAY. A WARMING TREND WILL BEGIN ON
MONDAY AS UPPER FLOW BECOMES MORE ZONAL FROM WEST TO EAST. ONE LOW
PRESSURE SYSTEM IS EXPECTED TO EJECT FROM THE SOUTHERN PLAINS
ACROSS SOUTHERN ILLINOIS MONDAY NIGHT AND TUESDAY. A WEAKER UPPER
TROUGH WILL SWING ACROSS NORTHERN ILLINOIS ON THURSDAY...SETTING
UP NORTHWEST FLOW ALOFT THROUGH FRIDAY.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
19Z SURFACE ANALYSIS SHOWS THE COLD FRONT APPROACHING THE
IOWA/ILLINOIS BORDER. RADAR SHOWS A NARROW LINE OF SHOWERS AND
STORMS ALONG THE FRONT IN IOWA...AND FARTHER SOUTHEAST AHEAD OF
THE FRONT IN EASTERN MISSOURI AND FAR WESTERN ILLINOIS. A BROAD
COVERAGE OF LIGHT RAIN SHOWERS EXTENDED ACROSS MUCH OF CENTRAL
ILLINOIS AND INTO WEST CENTRAL INDIANA. MOST AREAS IN CENTRAL
ILLINOIS WERE SEEING LESS THAN 0.10" OF RAIN OUT AHEAD OF THE
FRONT.
4KM NCEP AND HRRR OUTPUT INDICATE THE LINE WILL MAINTAIN SOME
INTENSITY DURING THE DAYLIGHT HOURS...BUT WEAKEN WITH SUNSET AS
THE LINE OF STORMS REACHES THE I-55 CORRIDOR. TIMING BASED ON
RADAR AND HRRR HAS THE LINE OF STORMS GENERALLY INTO INDIANA BY
08Z/3 AM. THE GFS/NAM/ECMWF/GEM ARE NOT FAR OFF FROM THAT
ASSESSMENT...SO WE HAVE UPDATED THE POPS LIKEWISE. BASICALLY,
SCATTERED COVERAGE IS EXPECTED ALONG AND AHEAD OF THE FRONT, SO
CHANCE POPS WERE USED /30-50 PCT/. SOME AREAS MAY SEE A STRONGER
UPDRAFT AND RECEIVED 0.25" RAIN IN A SHORT TIME, WHILE NEARBY
AREAS SEE LITTLE TO NO RAIN.
SATURDAY WILL FEATURE THE ARRIVAL OF A CHILLY CANADIAN AIR MASS AS
AIRFLOW BECOMES NORTH-NORTHWEST THROUGH A DEEP LAYER OF THE
ATMOSPHERE. 850MB TEMPS WILL DROP TO +6C IN OUR NORTH WITH 9-10C IN
THE SOUTH. ANY DAYTIME HEATING WILL CREATE STEEP LOW LEVEL LAPSE
RATES...WHICH WILL WORK TOGETHER WITH INCREASING BULK SHEAR AND
POSITIVE VORTICITY ADVECTION TO KICK OFF A FEW SHOWERS SATURDAY
AFTERNOON. MOST AREAS WILL PROBABLY REMAIN DRY...AND ANY RAIN THAT
DOES DEVELOP WILL NOT ADD UP TO 0.01"...SO WE WENT WITH SCATTERED
SPRINKLES FOR OUR NORTHERN COUNTIES SAT AFTN.
CLOUD COVER WILL DEVELOP QUICKLY IF ANY SUNSHINE BREAKS THROUGH
FOR ANY LENGTH OF TIME...WHICH WILL HELP TO KEEP HIGHS IN THE
70-73 DEG RANGE. WOULD NOT BE SURPRISED IF SOME LOCATIONS DO NOT
REACH 70 IF THE 6C LINE AT 850MB DOES REACH OUR COUNTIES. DRY
ADIABATIC MIXING OF 6C FROM 850MB WOULD ONLY PRODUCE A HIGH OF
66F. ANY SHOWERS WILL QUICKLY DISSIPATE WITH THE APPROACH OF
SUNSET.
RECORD OR NEAR RECORD LOWS ARE FORECAST FOR SATURDAY NIGHT.
CLEARING SKIES WILL BE A KEY COMPONENT OF THAT HAPPENING...BUT ALL
INDICATIONS ARE THAT CLOUDS WILL BE DIURNALLY DRIVEN AND SHOULD
DISSIPATE SAT EVE. LOW 50S WILL BE COMMON ACROSS THE FORECAST
AREA. RECORD LOW FOR PIA AND SPI SAT NIGHT IS 53.
SUNDAY MAY BE A CARBON COPY OF SATURDAY...WITH THE UPPER TROUGH
LINGERING ACROSS THE WESTERN GREAT LAKES AND INTO EASTERN
ILLINOIS, AND LITTLE CHANGE IN THE AIR MASS. SPOTTY SHOWERS AND
SPRINKLES WILL BE POSSIBLE...MAINLY IN THE NORTH CLOSER TO THE
COLDER AIR.
MONDAY WILL START A WARMING TREND AS THE UPPER TROUGH AXIS DEPARTS
TO THE EAST AND WESTERLY FLOW DEVELOP. THAT WILL SET THE STAGE FOR
A PROGRESSIVE LOW TO MOVE FROM THE PLAINS ACROSS SOUTHERN MISSOURI
AND SOUTHERN IL. SOME LOCALLY HEAVY RAIN WILL BE POSSIBLE LATER
MONDAY NIGHT AS THE LOW APPROACHES AND A WARM FRONT DEVELOPS
NEAR OUR SOUTHERN COUNTIES. THE MODELS HAVE TRENDED FARTHER SOUTH
WITH THE TRACK OF THE LOW THE LAST 2 MODEL RUNS...SO IT IS NOT OUT
OF THE QUESTION THAT LATER RUNS TAKE IT EVEN FARTHER SOUTH. WE
REDUCED LIKELY POPS TO CHANCE MONDAY NIGHT TO TREND DOWN...BUT
ADDED SOME LIKELY TO TUES IN OUR FAR SOUTHERN COUNTIES AS
GFS/ECMWF AGREE ON DECENT COVERAGE OF SHOWERS/STORMS DURING THE
DAY IN SOUTHERN IL RIGHT NOW. PRECIP WILL DIMINISH TUESDAY NIGHT
AS THE BULK OF THE FORCING FOR PRECIP DEPARTS TO THE EAST WITH THE
LOW.
WARMING WILL DEVELOP AHEAD OF THE LOW...AND DEWPOINTS WILL CLIMB
BACK INTO THE 60S WITH THE SYSTEM. LOCALLY HEAVY RAIN MAY DEVELOP
IN THE STRONGER STORMS...WITH RAINFALL RATES OF 1-2 INCHES PER
HOUR.
LONG TERM...WEDNESDAY THROUGH FRIDAY.
WEDNESDAY LOOKS MAINLY DRY AT THIS POINT, ALTHOUGH SOME ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE AS NORTHWEST FLOW RETURNS AND
500MB SHORTWAVES MOVE INTO THE AREA. DEWPOINTS WILL CLIMB INTO THE
UPPER 60S BY WEDNESDAY...SO MUGGY FEELING AIR WILL RETURN AS HIGHS
CLIMB INTO THE LOWER 80S. SOME MID 80S FOR HIGHS WILL BE POSSIBLE
ON THURSDAY AND FRIDAY AS 850MB TEMPS CLIMB BACK TO 14-16C. RAIN
CHANCES INCREASE MORE DRAMATICALLY ON FRIDAY PER THE GFS...WITH A
STRONGER SYSTEM DROPPING SOUTHEAST FROM THE NORTHERN PLAINS. THE
ECMWF LAGS THE GFS BY 24 HRS WITH THAT FEATURE.
SHIMON
&&
.AVIATION...
ISSUED 624 PM CDT FRI JUL 26 2013
LINE OF THUNDERSTORMS MOVING THROUGH KPIA NOW...AND SHOULD BE
CROSSING THE REMAINDER OF THE CENTRAL ILLINOIS TAF SITES IN THE
01-03Z TIME FRAME. MVFR CEILINGS HAVE BEEN ON THE INCREASE AHEAD
OF THIS LINE...WITH SOME PATCHES OF IFR ALONG AND IMMEDIATELY
BEHIND THE STORMS. THE LINE OF STORMS IS ALONG A COLD
FRONT...WHICH WILL BE THROUGH THE TAF SITES BY 06Z. SKIES EXPECTED
TO CLEAR SOME BEHIND IT...BUT HAVE LINGERED MVFR CEILINGS AT KCMI
THROUGH THE NIGHT AS THE FRONT STARTS TO SLOW DOWN A BIT.
DURING THE DAY ON SATURDAY...A STRONG UPPER LOW FOR THIS TIME OF
YEAR WILL BE DIGGING SOUTHWARD INTO NORTHERN ILLINOIS AND INDIANA.
THIS IS EXPECTED TO BRING EXTENSIVE DIURNAL CUMULUS AND PERHAPS
SOME LIGHT SHOWERS. FORECAST SOUNDINGS SHOWING THAT CEILINGS
SHOULD BE ABOVE 4000 FEET WITH THESE CLOUDS.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
314 PM CDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 311 PM CDT THU JUL 25 2013
12Z UA ANALYSIS HAS AN 850MB LOW NORTHWEST OF LAKE SUPERIOR AND
ANOTHER IN WESTERN NEBRASKA. A WARM FRONT RAN FROM THE NEBRASKA
850MB LOW INTO NORTHWEST IOWA BEFORE TURNING SOUTH. MOISTURE WAS
POOLED IN THE NORTHERN AND CENTRAL PLAINS NEAR THE 850MB LOW AND
WARM FRONT FROM NOCTURNAL STORMS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW NEW CONVECTION HAS
DEVELOPED FROM SOUTHERN MINNESOTA INTO WESTERN WISCONSIN ALONG WITH
A PERSISTENT CLUSTER OF STORMS FROM NEBRASKA INTO NORTHEAST KANSAS.
18Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHWEST MINNESOTA INTO
SOUTHERN SOUTH DAKOTA WITH A SLIGHTLY STRONGER LOW IN EASTERN
COLORADO. A WARM FRONT RAN FROM NORTHWEST KANSAS INTO LOUISIANA. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S FROM
WISCONSIN INTO THE PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
SATELLITE AND RADAR TRENDS SHOW CONVECTION NORTH OF THE CWFA AND
WELL SOUTHWEST OF THE CWFA. THE RAP TRENDS AND OTHER MODELS OF A
POSSIBLE SCENARIO OF CONVECTION NORTHEAST AND SOUTHWEST OF THE CWFA
TONIGHT MAY BE STARTING TO PLAY OUT. HOWEVER...RADAR DOES SHOW WEAK
CONVECTION DEVELOPING ACROSS NORTHERN IOWA AND ALONG THE MISSOURI
RIVER NEAR KOMA. THE MCS TOOL SUGGESTS ISOLATED TO SCATTERED
CONVECTION MOVING/DEVELOPING ACROSS THE NORTHWEST CWFA DURING THE
EVENING AND POSSIBLY BECOMING LOOSELY ORGANIZED LATE TONIGHT.
THE SIGNAL FOR A SUBSTANTIAL MCS DEVELOPING IN THE PLAINS AND
DROPPING SOUTHEAST OVERNIGHT IS STILL THERE IN ALL THE MODELS. IF
CORRECT...THIS MCS WOULD INTERCEPT THE MOISTURE INFLOW INTO THE AREA
AND THUS LIMIT THE POTENTIAL FOR RAIN. THOSE AREAS THAT DO SEE RAIN
OVERNIGHT MAY SEE AMOUNTS RANGING FROM 0.25 TO 0.50 INCHES.
CONVECTION THAT DEVELOPS TONIGHT WILL BE ACROSS THE AREA FRIDAY
MORNING WITH THE BETTER CHANCES OVER THE NORTHEAST CWFA WHERE BETTER
FORCING EXISTS. THE RAIN WILL END FROM WEST TO EAST DURING THE DAY
AS THE FRONT MOVES THROUGH WITH LINGERING CONVECTION OVER THE
SOUTHEAST HALF OF THE CWFA BY LATE AFTERNOON. CLOUD COVER MAY
INITIALLY SUPPRESS TEMPERATURES DURING THE DAY BUT CLEARING IN THE
AFTERNOON SHOULD PUSH TEMPERATURES INTO THE 75 TO 80 DEGREE
RANGE. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
A CLOSED UPPER LOW WILL REMAIN OVER THE WESTERN GREAT LAKES THROUGH
LATE SATURDAY THEN MOVES SLOWLY EAST REACHING NORTHERN MICHIGAN BY
SUNDAY EVENING. THE COLD FRONT ASSOCIATED WITH THE UPPER LOW SHOULD BE
NEAR THE MISSISSIPPI RIVER BY 00Z SATURDAY AND EAST OF THE FORECAST
AREA BY 06Z SATURDAY WITH BEST MID/UPPER FORCING AHEAD OF THE UPPER
TROF SHIFTING EAST OF THE FORECAST AREA BY 06Z. THIS SUPPORTS
THE GOING FORECAST OF SLIGHT CHANCE POPS EAST FRIDAY EVENING THEN
DRY AFTER MIDNIGHT. THE REST OF THE WEEKEND LOOKS DRY WITH NORTH TO
NORTHWEST FLOW DOMINATING THE REGION. SATURDAY AFTERNOON/EVENING
WILL HAVE TO WATCH THE NORTHEASTERN CWFA FOR POTENTIAL DIURNAL SHRA
AS THE H5 COLD POOL MOVES THROUGH. NEAR RECORD TEMPS FOR SATURDAY
AND SUNDAY MORNING STILL LOOK ON TRACK. KEPT SATURDAYS LOWS ON THE
WARM SIDE OF GUIDANCE WITH THE POTENTIAL FOR SOME COLD AIR SC MOVING
THE THROUGH FRIDAY NIGHT. FORECAST MINS FOR SATURDAY STAY JUST ABOVE
THE RECORDS. SUNDAY LIGHTER SURFACE WINDS AND LESS OF THREAT OF
SIGNIFICANT CLOUD COVER SUPPORTS COOLER MINS THAN SATURDAY AND A
BETTER POTENTIAL OF REACHING RECORD MINS. THE COOL AIRMASS WILL
KEEP HIGHS SATURDAY AND SUNDAY IN THE LOW TO MID 70S. NORMALS HIGHS
FOR LATE JULY ARE IN THE LOW TO MID 80S.
THE GREAT LAKES REGION UPPER LOW WILL DRIFT NORTHEAST INTO EASTERN
CANADA BY MID TO LATE WEEK AS WESTERLY MID LEVEL FLOW SPREADS EAST
INTO THE CENTRAL U.S. A S/W ON THE LEADING EDGE OF THE WESTERLY
FLOW REGIME IS PROGGED TO MOVE THROUGH THE CENTRAL U.S. MONDAY AND
TUESDAY. MODELS ARE IN GOOD AGREEMENT DEVELOPING A PLAINS MCS IN
THE RETURN FLOW AHEAD OF THE S/W AND MOVING THE MCS EAST INTO THE
MID MISSISSIPPI VALLEY LATE MONDAY NIGHT OR TUESDAY. THE 12Z
GFS/GEM BROUGHT THE BULK OF THE PRECIP WITH THIS SYSTEM THROUGH IA
AND NORTHERN ILLINOIS WHILE THE 12Z ECMWF WAS A TAD SOUTH FOCUSING
MORE ON NORTHERN MO AND SOUTHERN IA INTO CENTRAL AND SOUTHERN IL.
WITH ALL OF THE MODELS HITTING SOME PART OF THE FORECAST AREA HAVE
UPPED POPS TO HIGH CHANCE OR LIKELY WITH THE HIGHEST POPS MONDAY
NIGHT. THE GFS/ECMWF SUGGEST ANOTHER S/W MOVING THROUGH BY THURSDAY
BUT THE FEATURES LOOK WEAK AT THIS TIME SO SLIGHT CHANCE OR LOW
CHANCE POPS ARE MENTIONED FOR NOW. TEMPERATURES WILL BE ON A
GRADUAL WARMING TREND THROUGH THE WEEK AND SHOULD BE BACK TO NEAR
NORMAL FOR EARLY AUGUST BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU JUL 25 2013
VFR WX WILL BE SEEN THROUGH 00Z/26 AS HIGH PRESSURE CONTINUES
MOVING EAST THROUGH THE GREAT LAKES. AFT 00Z/26 CONVECTION WILL
DEVELOP AHEAD OF AN APPROACHING COLD FRONT AND MAY EVOLVE INTO A
WEAKLY ORGANIZED SYSTEM. INITIALLY THE PROBABILITY OF A SHRA OR
TSRA HITTING A TAF SITE WILL BE LOW. AFT 03Z/26 THE CHANCES WILL
BE ON THE INCREASE. AFT 03Z/26 VFR CONDITIONS ARE FCST FOR ALL TAF
SITES BUT THE POSSIBILITY DOES EXIST FOR MVFR OR IFR CONDITIONS IF
A TSRA AFFECTS A TAF SITE. ..08..
&&
.CLIMATE...
ISSUED AT 311 PM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
CLIMATE...14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
100 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1249 PM CDT THU JUL 25 2013
SATELLITE SHOWS SOME VERY WEAK DIURNAL CU HAS DEVELOPED IN THE
PAST HOUR INDICATING THE TRIGGER TEMPERATURE FOR THERMALS HAS BEEN
ACHIEVED. TRENDS WITH THE RAP CONTINUE TO SHOW THE CONVECTIVE
TEMPERATURE CLIMBING INTO THE MID AND UPPER 80S DURING THE
AFTERNOON WHICH IS HIGHER THAN THE FCST MAX TEMPERATURES.
AN APPROACHING MCV MAY BE THE TRIGGER TO HELP INITIATE ISOLATED TO
SCATTERED CONVECTION BY LATE AFTERNOON. HOWEVER...MOST OF THE AREA
IS EXPECTED TO REMAIN DRY THROUGH SUNSET.
THE MCS AND LIFT TOOLS ARE SUGGESTING CONVECTION THAT DEVELOPS
MAY TRY TO ORGANIZE INTO A VERY WEAK MCS. IF THIS OCCURS THEN
THERE WOULD BE UPSCALE GROWTH OF THE PRECIPITATION SHIELD FOR THE
AREA. A CONCERN IS THAT THE BETTER DYNAMICS ARE NORTHEAST OF THE
AREA AND THE BETTER THERMODYNAMICS ARE ACROSS THE CENTRAL AND
SOUTHERN PLAINS. THE MCS TOOL DOES INDICATE A WELL ORGANIZED MCS
DEVELOPING IN THE PLAINS AND DROPPING SOUTH OVERNIGHT WHICH COULD
ROB NEEDED MOISTURE FOR CONVECTION OVER THE CWFA. ..08..
UPDATE ISSUED AT 1013 AM CDT THU JUL 25 2013
THERE ARE QUESTIONS ON WHETHER OR NOT CONVECTION WILL BE SEEN IN
THE CWFA PRIOR TO EVENING. THE 12Z SOUNDING HAS A CONVECTIVE
TEMPERATURE IN THE UPPER 70S. HOWEVER...RAP AND OTHER MODEL TRENDS
SHOW THIS CLIMBING INTO THE 80S AS THE DAY PROGRESSES. THE LACK OF
ANY DIURNAL CU AT THIS POINT IN THE DAY INDICATES THAT THE TRIGGER
TEMPERATURE TO GENERATE THERMALS HAS YET TO BE ACHIEVED.
THE LATE MORNING AND EARLY AFTERNOON HOURS WILL REMAIN DRY ACROSS
THE AREA. THE QUESTION BECOMES LATE AFTERNOON DURING PEAK HEATING.
THE MCS AND LIFT TOOLS FROM THE ECMWF/UKMET/GEM INDICATE DRY
CONDITIONS LATE THIS AFTERNOON AND THROUGH SUNSET. THE WRF/GFS
HAVE CONVECTION INTO THE NORTHERN/WESTERN PARTS OF THE CWFA BY
LATE AFTERNOON AND OVER MOST OF THE AREA BY SUNSET. THE RAP KEEPS
MOST OF THE AREA DRY THROUGH LATE AFTERNOON BUT BRINGS IN
CONVECTION INTO THE WESTERN PARTS OF THE CWFA JUST PRIOR TO
EVENING.
SO...WILL GO WITH THE IDEA OF KEEPING NEARLY ALL OF THE CWFA DRY
THROUGH LATE AFTERNOON WITH POSSIBLY SOME CONVECTION NORTH OF HWY
20 BETWEEN KDBQ AND KALO JUST BEFORE EVENING. DURING THE EVENING
WILL GO WITH CONVECTION DEVELOPING/SPREADING SOUTH AND EAST ACROSS
THE CWFA. ..08..
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUL 25 2013
COOL AND QUIET CONDITIONS WERE FOUND ACROSS THE AREA EARLY THIS
MORNING AS HIGH PRESSURE...REACHING FROM THE GREAT LAKES
SOUTHEAST ACROSS IL AND MO...REMAINS IN CONTROL. TEMPERATURES WERE
IN THE 50S TO LOWER 60S WITH DEWPOINTS MAINLY IN THE LOWER 50S
UNDER MOSTLY CLEAR SKIES. MORE ACTIVE WEATHER WAS FOUND ACROSS THE
PLAINS...WHERE SHORTWAVES IN THE NW FLOW WERE INTERACTING WITH
GULF MOISTURE RETURN...RESULTING IN SEVERAL THUNDERSTORM
CLUSTERS. THE LOCAL FOCUS IS ON A SHORTWAVE EVIDENT ON WV IMAGES
JUST NW OF LAKE WINNIPEG THAT IS PROGGED TO TRAVEL SOUTHEAST INTO
THE EASTERN U.S. TROUGH...DIGGING INTO A CLOSED UPPER LOW OVER THE
GREAT LAKES BY FRIDAY. IN THE PROCESS...IT WILL SWEEP A COLD FRONT
THROUGH THE FORECAST AREA EARLY FRIDAY TRIGGERING WIDESPREAD
SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
MAIN FOCUS IS ON THUNDERSTORM CHANCES LATER TODAY THROUGH FRIDAY.
TODAY...THE SURFACE HIGH WILL CONTINUE TO MIGRATE EAST...ALLOWING A
LOW LEVEL RETURN FLOW AND WARM ADVECTION. THE GFS AND WRF/NAM APPEAR
TOO AGGRESSIVE WITH THIS LOW LEVEL MOISTURE RETURN...RESULTING IN
DEWPOINTS SHOWN REACHING THE UPPER 60S TO MID 70S BY AFTERNOON
OVER EASTERN IA. THIS THEN LEADS TO HIGHER CAPES AND A FASTER
ONSET OF THUNDERSTORMS INTO EASTERN IA WELL OUT AHEAD OF THE
SURFACE COLD FRONT THIS AFTERNOON. THE MORE REASONABLE ECMWF AND
GEM LOW LEVEL MOISTURE FIELDS KEEP THE THUNDERSTORMS WELL WEST
AND NW OF THE FORECAST AREA DURING THE DAY. WITH LIGHT WINDS AND
POSSIBLE OUTFLOW BOUNDARIES UNDER A DEVELOPING SLIGHTLY DIFLUENT
FLOW ALOFT AHEAD OF THE APPROACHING SHORTWAVE...CANNOT COMPLETELY RULE
OUT SHOWERS AND THUNDERSTORMS REACHING THE FAR NW BY LATE AFTERNOON
AND WILL CARRY LOW CHANCE POPS. WITH LIGHT SOUTH TO SOUTHEAST
WINDS AND WARM ADVECTION...HAVE KEPT HIGHS IN THE UPPER 70S TO
LOWER 80S. WILL ANTICIPATE INCREASING MID AND HIGH CLOUDS FROM
UPSTREAM CONVECTION TO PREVENT EVEN WARMER TEMPERATURES.
TONIGHT INTO FRIDAY...THE PRIMARY AXIS OF GULF MOISTURE AT 850 MB SPREADS
INTO THE FORECAST AREA UNDER AN INCREASINGLY DIFLUENT FLOW ALOFT.
MODELS CONTINUE TO DEPICT THE STRONGEST UPPER FORCING AHEAD OF THE
DEVELOPING UPPER LOW TO THE NORTH ACROSS MN INTO WI...BUT DECENT
QG FORCING IS SHOWN DEVELOPING INTO THE FORECAST AREA ALONG WITH
MODEST THETAE CONVERGENCE...ESPECIALLY FROM 12Z TO 18Z COINCIDING
WITH THE ADVANCING SURFACE COLD FRONT. THERE REMAINS SOME CONCERN
IN HOW A SEPARATE STRONG SHORTWAVE IN THE PLAINS AND RESULTING
MCS MAY AFFECT THE MOISTURE FEED FURTHER NORTH AND NORTHEAST...
WHICH MAY LIMIT THE STRENGTH AND SIZE OF THE PREFRONTAL MCS THAT
WILL BE FAVORED TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT
INTO FRIDAY MORNING. WILL THUS KEEP QPF AMOUNTS OF A FEW TENTHS TO
NEAR A HALF INCH OVER THE AREA WITH LIKELY POPS CENTERED FROM LATE
TONIGHT THROUGH FRIDAY MORNING. THIS TIMING WILL NOT BE FAVORABLE
FOR SEVERE WEATHER BEYOND SOME SUB-SEVERE WIND GUSTS WITH THE
STRONGEST STORMS. MODELS ARE IN GENERAL AGREEMENT WITH THE SURFACE
FRONT CROSSING EAST OF THE MS RIVER AROUND NOON FRIDAY AND HAVE
LIMITED AFTERNOON POPS TO SLIGHT OR LOW END CHANCE POPS TO THE
WEST...WITH HIGHER CHANCES TO THE EAST THROUGH THE AFTERNOON.
CLOUDS AND HIGHER DEWPOINTS WILL HOLD TEMPERATURES IN THE 60S FOR
LOWS TONIGHT. WITH GRADUAL CLEARING FROM WEST TO EAST FRIDAY
AFTERNOON AND DEVELOPING POST-FRONTAL COOL ADVECTION W-NW
WINDS...HAVE HIGHS LIMITED TO THE LOWER TO MID 70S...WITH SOME UPPER
70S POSSIBLE IN THE SOUTH AND EAST WHERE THE FROPA WILL BE LATEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
FRIDAY NIGHT... WALKED OUT PCPN CHANCES DURING THE EVENING HOURS...
WITH THE ENTIRE CWFA PCPN-FREE BY 03Z. CANADIAN HIGH PRESSURE THEN
USHERS IN COOL AND DRY CONDITIONS ON A LIGHT NNW BREEZE...WITH 850MB
TEMPS OF 6-8C COMING DOWN ACROSS THE AREA. NEAR RECORD OR RECORD COLD
TEMPERATURES ARE POSSIBLE BOTH EARLY SATURDAY MORNING AND AGAIN
SUNDAY MORNING...WITH SUNDAY HAVING THE BETTER POTENTIAL. LOWS BOTH
MORNINGS WILL BE IN THE UPPER 40S TO MID 50S. DAYTIME HIGHS ON
SATURDAY WILL STRUGGLE TO REACH THE UPPER 60S TO NEAR 70 ALONG
HIGHWAY 20...WHILE TO THE SOUTH THEY WILL INCH UPWARDS INTO THE
LOWER TO MIDDLE 70S. WITH NNW WINDS AT 10-15 MPH SAT PM...IT WILL
FEEL QUITE FALL-LIKE. SUNDAY WILL BE SLIGHTLY WARMER WITH HIGHS IN
THE LOWER 70S NORTH TO UPPER 70S SOUTH ALONG WITH LIGHTER WINDS.
MONDAY THROUGH WEDNESDAY TEMPERATURES WILL MAINLY BE IN THE MID 70S
TO LOW 80S...BUT STILL BELOW NORMAL. MODELS CONTINUE TO INDICATE
THAT THE UPPER LEVEL RIDGE WILL BREAK DOWN/MOVE EAST/ ALLOWING A
SHORT WAVE TO MOVE ACROSS THE CENTRAL PLAINS INTO MO MONDAY INTO
TUESDAY...POSSIBLY BRINGING AN MCS GENERALLY EASTWARD ALONG THE
IA/MO BORDER. THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS STILL
LOOK TO BE DURING THE MONDAY NIGHT AND TUESDAY TIME FRAME. MODEL
CONSENSUS HAS POPS FOR MON NIGHT AT 40-50 WITH 30 POP FOR
TUESDAY...WITH GENERALLY SLIGHT CHANCES BEFORE AND AFTER. AT THIS
TIME...IT APPEARS AREAS SOUTH OF I 80 HAVE THE BEST CHANCE AT SEEING
THIS ACTIVITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU JUL 25 2013
VFR WX WILL BE SEEN THROUGH 00Z/26 AS HIGH PRESSURE CONTINUES
MOVING EAST THROUGH THE GREAT LAKES. AFT 00Z/26 CONVECTION WILL
DEVELOP AHEAD OF AN APPROACHING COLD FRONT AND MAY EVOLVE INTO A
WEAKLY ORGANIZED SYSTEM. INITIALLY THE PROBABILITY OF A SHRA OR
TSRA HITTING A TAF SITE WILL BE LOW. AFT 03Z/26 THE CHANCES WILL
BE ON THE INCREASE. AFT 03Z/26 VFR CONDITIONS ARE FCST FOR ALL TAF
SITES BUT THE POSSIBILITY DOES EXIST FOR MVFR OR IFR CONDITIONS IF
A TSRA AFFECTS A TAF SITE. ..08..
&&
.CLIMATE...
ISSUED AT 335 AM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...08
CLIMATE...14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1023 AM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1013 AM CDT THU JUL 25 2013
THERE ARE QUESTIONS ON WHETHER OR NOT CONVECTION WILL BE SEEN IN
THE CWFA PRIOR TO EVENING. THE 12Z SOUNDING HAS A CONVECTIVE
TEMPERATURE IN THE UPPER 70S. HOWEVER...RAP AND OTHER MODEL TRENDS
SHOW THIS CLIMBING INTO THE 80S AS THE DAY PROGRESSES. THE LACK OF
ANY DIURNAL CU AT THIS POINT IN THE DAY INDICATES THAT THE TRIGGER
TEMPERATURE TO GENERATE THERMALS HAS YET TO BE ACHIEVED.
THE LATE MORNING AND EARLY AFTERNOON HOURS WILL REMAIN DRY ACROSS
THE AREA. THE QUESTION BECOMES LATE AFTERNOON DURING PEAK HEATING.
THE MCS AND LIFT TOOLS FROM THE ECMWF/UKMET/GEM INDICATE DRY
CONDITIONS LATE THIS AFTERNOON AND THROUGH SUNSET. THE WRF/GFS
HAVE CONVECTION INTO THE NORTHERN/WESTERN PARTS OF THE CWFA BY
LATE AFTERNOON AND OVER MOST OF THE AREA BY SUNSET. THE RAP KEEPS
MOST OF THE AREA DRY THROUGH LATE AFTERNOON BUT BRINGS IN
CONVECTION INTO THE WESTERN PARTS OF THE CWFA JUST PRIOR TO
EVENING.
SO...WILL GO WITH THE IDEA OF KEEPING NEARLY ALL OF THE CWFA DRY
THROUGH LATE AFTERNOON WITH POSSIBLY SOME CONVECTION NORTH OF HWY
20 BETWEEN KDBQ AND KALO JUST BEFORE EVENING. DURING THE EVENING
WILL GO WITH CONVECTION DEVELOPING/SPREADING SOUTH AND EAST ACROSS
THE CWFA. ..08..
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUL 25 2013
COOL AND QUIET CONDITIONS WERE FOUND ACROSS THE AREA EARLY THIS
MORNING AS HIGH PRESSURE...REACHING FROM THE GREAT LAKES
SOUTHEAST ACROSS IL AND MO...REMAINS IN CONTROL. TEMPERATURES WERE
IN THE 50S TO LOWER 60S WITH DEWPOINTS MAINLY IN THE LOWER 50S
UNDER MOSTLY CLEAR SKIES. MORE ACTIVE WEATHER WAS FOUND ACROSS THE
PLAINS...WHERE SHORTWAVES IN THE NW FLOW WERE INTERACTING WITH
GULF MOISTURE RETURN...RESULTING IN SEVERAL THUNDERSTORM
CLUSTERS. THE LOCAL FOCUS IS ON A SHORTWAVE EVIDENT ON WV IMAGES
JUST NW OF LAKE WINNIPEG THAT IS PROGGED TO TRAVEL SOUTHEAST INTO
THE EASTERN U.S. TROUGH...DIGGING INTO A CLOSED UPPER LOW OVER THE
GREAT LAKES BY FRIDAY. IN THE PROCESS...IT WILL SWEEP A COLD FRONT
THROUGH THE FORECAST AREA EARLY FRIDAY TRIGGERING WIDESPREAD
SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
MAIN FOCUS IS ON THUNDERSTORM CHANCES LATER TODAY THROUGH FRIDAY.
TODAY...THE SURFACE HIGH WILL CONTINUE TO MIGRATE EAST...ALLOWING A
LOW LEVEL RETURN FLOW AND WARM ADVECTION. THE GFS AND WRF/NAM APPEAR
TOO AGGRESSIVE WITH THIS LOW LEVEL MOISTURE RETURN...RESULTING IN
DEWPOINTS SHOWN REACHING THE UPPER 60S TO MID 70S BY AFTERNOON
OVER EASTERN IA. THIS THEN LEADS TO HIGHER CAPES AND A FASTER
ONSET OF THUNDERSTORMS INTO EASTERN IA WELL OUT AHEAD OF THE
SURFACE COLD FRONT THIS AFTERNOON. THE MORE REASONABLE ECMWF AND
GEM LOW LEVEL MOISTURE FIELDS KEEP THE THUNDERSTORMS WELL WEST
AND NW OF THE FORECAST AREA DURING THE DAY. WITH LIGHT WINDS AND
POSSIBLE OUTFLOW BOUNDARIES UNDER A DEVELOPING SLIGHTLY DIFLUENT
FLOW ALOFT AHEAD OF THE APPROACHING SHORTWAVE...CANNOT COMPLETELY RULE
OUT SHOWERS AND THUNDERSTORMS REACHING THE FAR NW BY LATE AFTERNOON
AND WILL CARRY LOW CHANCE POPS. WITH LIGHT SOUTH TO SOUTHEAST
WINDS AND WARM ADVECTION...HAVE KEPT HIGHS IN THE UPPER 70S TO
LOWER 80S. WILL ANTICIPATE INCREASING MID AND HIGH CLOUDS FROM
UPSTREAM CONVECTION TO PREVENT EVEN WARMER TEMPERATURES.
TONIGHT INTO FRIDAY...THE PRIMARY AXIS OF GULF MOISTURE AT 850 MB SPREADS
INTO THE FORECAST AREA UNDER AN INCREASINGLY DIFLUENT FLOW ALOFT.
MODELS CONTINUE TO DEPICT THE STRONGEST UPPER FORCING AHEAD OF THE
DEVELOPING UPPER LOW TO THE NORTH ACROSS MN INTO WI...BUT DECENT
QG FORCING IS SHOWN DEVELOPING INTO THE FORECAST AREA ALONG WITH
MODEST THETAE CONVERGENCE...ESPECIALLY FROM 12Z TO 18Z COINCIDING
WITH THE ADVANCING SURFACE COLD FRONT. THERE REMAINS SOME CONCERN
IN HOW A SEPARATE STRONG SHORTWAVE IN THE PLAINS AND RESULTING
MCS MAY AFFECT THE MOISTURE FEED FURTHER NORTH AND NORTHEAST...
WHICH MAY LIMIT THE STRENGTH AND SIZE OF THE PREFRONTAL MCS THAT
WILL BE FAVORED TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT
INTO FRIDAY MORNING. WILL THUS KEEP QPF AMOUNTS OF A FEW TENTHS TO
NEAR A HALF INCH OVER THE AREA WITH LIKELY POPS CENTERED FROM LATE
TONIGHT THROUGH FRIDAY MORNING. THIS TIMING WILL NOT BE FAVORABLE
FOR SEVERE WEATHER BEYOND SOME SUB-SEVERE WIND GUSTS WITH THE
STRONGEST STORMS. MODELS ARE IN GENERAL AGREEMENT WITH THE SURFACE
FRONT CROSSING EAST OF THE MS RIVER AROUND NOON FRIDAY AND HAVE
LIMITED AFTERNOON POPS TO SLIGHT OR LOW END CHANCE POPS TO THE
WEST...WITH HIGHER CHANCES TO THE EAST THROUGH THE AFTERNOON.
CLOUDS AND HIGHER DEWPOINTS WILL HOLD TEMPERATURES IN THE 60S FOR
LOWS TONIGHT. WITH GRADUAL CLEARING FROM WEST TO EAST FRIDAY
AFTERNOON AND DEVELOPING POST-FRONTAL COOL ADVECTION W-NW
WINDS...HAVE HIGHS LIMITED TO THE LOWER TO MID 70S...WITH SOME UPPER
70S POSSIBLE IN THE SOUTH AND EAST WHERE THE FROPA WILL BE LATEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
FRIDAY NIGHT... WALKED OUT PCPN CHANCES DURING THE EVENING HOURS...
WITH THE ENTIRE CWFA PCPN-FREE BY 03Z. CANADIAN HIGH PRESSURE THEN
USHERS IN COOL AND DRY CONDITIONS ON A LIGHT NNW BREEZE...WITH 850MB
TEMPS OF 6-8C COMING DOWN ACROSS THE AREA. NEAR RECORD OR RECORD COLD
TEMPERATURES ARE POSSIBLE BOTH EARLY SATURDAY MORNING AND AGAIN
SUNDAY MORNING...WITH SUNDAY HAVING THE BETTER POTENTIAL. LOWS BOTH
MORNINGS WILL BE IN THE UPPER 40S TO MID 50S. DAYTIME HIGHS ON
SATURDAY WILL STRUGGLE TO REACH THE UPPER 60S TO NEAR 70 ALONG
HIGHWAY 20...WHILE TO THE SOUTH THEY WILL INCH UPWARDS INTO THE
LOWER TO MIDDLE 70S. WITH NNW WINDS AT 10-15 MPH SAT PM...IT WILL
FEEL QUITE FALL-LIKE. SUNDAY WILL BE SLIGHTLY WARMER WITH HIGHS IN
THE LOWER 70S NORTH TO UPPER 70S SOUTH ALONG WITH LIGHTER WINDS.
MONDAY THROUGH WEDNESDAY TEMPERATURES WILL MAINLY BE IN THE MID 70S
TO LOW 80S...BUT STILL BELOW NORMAL. MODELS CONTINUE TO INDICATE
THAT THE UPPER LEVEL RIDGE WILL BREAK DOWN/MOVE EAST/ ALLOWING A
SHORT WAVE TO MOVE ACROSS THE CENTRAL PLAINS INTO MO MONDAY INTO
TUESDAY...POSSIBLY BRINGING AN MCS GENERALLY EASTWARD ALONG THE
IA/MO BORDER. THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS STILL
LOOK TO BE DURING THE MONDAY NIGHT AND TUESDAY TIME FRAME. MODEL
CONSENSUS HAS POPS FOR MON NIGHT AT 40-50 WITH 30 POP FOR
TUESDAY...WITH GENERALLY SLIGHT CHANCES BEFORE AND AFTER. AT THIS
TIME...IT APPEARS AREAS SOUTH OF I 80 HAVE THE BEST CHANCE AT SEEING
THIS ACTIVITY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 613 AM CDT THU JUL 25 2013
LIGHT AND VARIABLE WINDS WILL TURN TO THE SOUTH BY AFTERNOON AS
HIGH PRESSURE SHIFTS EAST OF THE REGION. CONDITIONS WILL REMAIN
VFR WITH PERIODS OF MID AND HIGH LEVEL CLOUDS THROUGH THE DAY.
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AND POSSIBLY MOVE
INTO EASTERN IA THIS EVENING...THEN LIKELY BECOME MORE WIDESPREAD
AFTER MIDNIGHT INTO FRIDAY MORNING AS A COLD FRONT MOVES THROUGH
THE REGION. THE LATEST FORECASTS HAVE THIS HANDLED WITH PROB30
GROUPS IN THE EVENING...THEN PREVAILING SHOWER AND THUNDERSTORM
COVERAGE WITH MVFR VISIBILITIES AFTER MIDNIGHT AT CID...DBQ AND
MLI. THE POTENTIAL FOR THUNDERSTORMS REACHING THE BRL SITE IS LESS
CERTAIN THUS ONLY A PROB30 GROUP IS INCLUDED TOWARD SUNRISE.
&&
.CLIMATE...
ISSUED AT 335 AM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...SHEETS
CLIMATE...14
AREA FORECAST DISCUSSION
NWS TOPEKA KS
557 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 557 PM CDT THU JUL 25 2013
BASED ON 22Z OBS AND OBJECTIVE STREAM LINE ANALYSIS..IT APPEARS AS
THOUGH THE DEEP MOIST CONVECTION IS OCCURRING WITHIN THE AREAS OF
LOW LEVEL CONVERGENCE. FOR THE IMMEDIATE FUTURE...THIS WOULD FAVOR
CONVECTION STAYING GENERALLY SOUTH OF I-70. THE NAM AND RAP SHOW A
LOW LEVEL JET PERSISTING FROM THE SOUTH AND SOUTHWEST AHEAD OF THE
SYNOPTIC COLD FRONT WITH SOME ISENTROPIC UPGLIDE. SO WHILE THE
BETTER SHORTWAVE FORCING MAY END UP SKIRTING THE SOUTHWESTERN
PORTIONS OF THE FORECAST AREA...THINK STORMS THAT FILL IN THE GAP
ALONG THE FRONT IN NEB FROM THE MO RIVER TO NORTHWEST KS SHOULD
PERSIST AND MOVE THROUGH MUCH OF NORTHEAST KS. WILL MONITOR TRENDS
FOR A LITTLE WHILE TO SEE IF IN FACT THIS IS THE CASE...BUT MAY
NEED TO ADJUST POPS UP A LITTLE FOR THE OVERNIGHT HOURS. CHANCES
FOR SEVERE WEATHER LOOK TO BE THE HIGHEST THIS EVENING WITH
REASONABLE MID LEVEL LAPSE RATES SUGGESTING SOME ELEVATED
INSTABILITY AND DEEP LAYER SHEAR AROUND 30 KTS SUPPORTIVE OF SOME
ORGANIZATIONS. HOWEVER MODELS TEND TO SHALLOW UP THE LAPSE RATES
AFTER MIDNIGHT. HOPEFULLY THIS MEANS WE WILL JUST GET SOME
BENEFICIAL RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
SEVERAL FORCING MECHANISMS COMING INTO PLAY FOR HIGH PRECIPITATION
CHANCES THROUGH EARLY FRIDAY. UPPER LEVEL JET WAS ROTATING
ANTICYCLONICALLY AROUND THE GREAT BASING RIDGE AND INTO CENTRAL
COLORADO AT 12Z WITH 40-50M HEIGHT FALLS /HIGH FOR JULY/ AT THE
WESTERN NEBRASKA VICINITY RAOBS. WEAK RIDGING AT 700MB AND 850MB
OVER THE CENTRAL PLAINS LEADING TO MODEST WARM AIR ADVECTION WITH
INCREASING MOISTURE LEADING TO SCATTERED TO WIDESPREAD BUT MOSTLY
MODEST CONVECTION IN NORTHEASTERN KANSAS TODAY. 20Z OBSERVATIONS AND
PRESSURE CHANGES SUGGEST A COLD FROM FROM EAST CENTRAL COLORADO TO
NORTHEAST NEBRASKA...WITH VEERING UPPER LEVEL WINDS ON THE
PLATTEVILLE COLORADO WIND PROFILER. MIXED LAYER CAPE REMAINS RATHER
LIMITED WITH VALUES IN THE 1000 J/KG RANGE.
WARM AIR ADVECTION TO GRADUALLY SHIFT TO SHORTWAVE AND FINALLY
FRONTAL FORCING THROUGH FRIDAY MORNING AS PRECIPITABLE WATER LEVELS
RISE. SOME QUESTIONS REMAIN IF STRONGER LOW LEVEL FORCING AND
INSTABILITY IN SOUTHWEST KANSAS WILL KEEP THE BULK OF WIDESPREAD
PRECIP TO THE SOUTH SO KEPT SOME UNCERTAINTY IN THE PRECIPITATION
CHANCES. SEVERE CHANCES SEEM SOMEWHAT LOW GIVEN MARGINAL INSTABILITY
AND ONGOING COVERAGE OF CONVECTION LIMITING FURTHER INSOLATION.
PRECIP SHOULD END BY EARLY AFTERNOON FOR THE AREA AS THE FRONT
SHIFTS SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
FRIDAY NIGHT HIGH PRESSURE WILL BUILD INTO EASTERN KANSAS AND WILL
LOWER HUMIDITY AND YIELD LOWS IN THE 50S. SATURDAY LOOKS TO REMAIN
DRY FOR THE MOST PART, BUT WITH THE APPROACH OF A MID LEVEL WAVE
DEVELOPING CONVECTION IN NEBRASKA MAY SEE SOME SHOWERS OR
THUNDERSTORMS IN NORTH CENTRAL KANSAS. HIGHS SATURDAY WILL BE BELOW
NORMAL WITH READINGS IN THE UPPER 70S TO LOWER 80S.
SATURDAY NIGHT THUNDERSTORMS DEVELOPING IN THE HIGH PLAINS WILL MOVE
SOUTHEAST IN NORTHWEST FLOW ALOFT AND MAY CLIP THE WESTERN SECTIONS
OF THE CWA AFTER 09Z SUNDAY. PRECIPITATION CHANCES WILL INCREASE
SUNDAY AS A MID LEVEL WAVE MOVES EAST OUT OF THE ROCKIES AND
CONTINUES EASTWARD IN ZONAL FLOW ACROSS THE CENTRAL PLAINS. BEST
CHANCES WILL BE FROM THE AFTERNOON SUNDAY THROUGH SUNDAY NIGHT.
ANOTHER WAVE WILL MOVE ACROSS THE STATE ON MONDAY. GOOD MOISTURE
TRANSPORT EXPECTED SUNDAY NIGHT AND MONDAY EAST OF A SURFACE TROUGH
IN THE WESTERN HIGH PLAINS. THIS MAY LEAD TO SOME LOCALLY HEAVY
RAINFALL ESPECIALLY IN EAST CENTRAL KANSAS WHERE PRECIPITABLE WATER
WILL BE THE HIGHEST. LOW LEVEL JET WILL INTERACT WITH A FRONTAL
BOUNDARY MONDAY NIGHT AND TUESDAY MORNING. BY TUESDAY AFTERNOON THE
FORCING AND MOISTURE WILL MOVE OFF TO THE SOUTHEAST AND EAST WITH
THE FRONT SO WILL KEEP MORNING SHOWERS BEFORE DRYING OUT AGAIN.
NEXT WEDNESDAY SOME WEAK FORCING MAY BRING A SMALL CHANCE OF
THUNDERSTORMS TO THE AREA AS THEY ADVECT IN FROM THE WEST IN A NEARLY
ZONAL FLOW ALOFT. BETTER CHANCES COME NEXT THURSDAY AS MOISTURE
RETURNS AHEAD OF A DEVELOPING SURFACE TROUGH IN THE HIGH PLAINS WITH
AN MCS DEVELOPING IN THE HIGH PLAINS AND MOVING INTO EASTERN KANSAS.
TEMPERATURES WILL WARM FROM THE 80S TO LOWER TO MID 90S FROM MONDAY
THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 557 PM CDT THU JUL 25 2013
NO REAL CHANGE IN FORECAST THINKING AS HIRES MODELS CONTINUE TO
SHOW THE BEST TIMING FOR CONVECTION TO MOVE THROUGH THE TERMINALS
BETWEEN 07Z AND 13Z. NAM AND RAP CONTINUE TO SHOW THE POTENTIAL
FOR MVFR CIGS WITH THE CONVECTION. ONE MINOR CHANGES WAS TO HANG
ONTO THE MVFR CIGS A LITTLE LONGER INTO THE MORNING UNTIL THE LOW
LEVEL DRY AIR PUSHES THE RH SOUTH.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...65
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
955 PM EDT FRI JUL 26 2013
.SYNOPSIS...
ISSUED AT 415 PM EDT FRI JUL 26 2013
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY ADVANCE
THROUGH THE STATE...TODAY THROUGH SATURDAY. THIS SYSTEM WILL PRODUCE
A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT...WITH THE
BULK OF THE RAINFALL OCCURRING LATE THIS AFTERNOON AND THIS EVENING.
RAIN MAY BE HEAVY AT TIMES...PARTICULARLY OVER THE EASTERN UPPER
PENINSULA.
BEHIND THE FRONT...SUBSTANTIALLY COOLER AIR WILL SETTLE INTO THE
GREAT LAKES FOR THE UPCOMING WEEKEND KNOCKING TEMPERATURES DOWN TO
WELL BELOW NORMAL READINGS FOR LATE JULY. THIS WILL LEAD TO
ADDITIONAL SHOWERS DEVELOPING ON SATURDAY AND PERSISTING THROUGH
SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 949 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: CONTINUE TO REFINE NEAR TERM POPS/WX AS DEEP
MOISTURE PLUME AND ASSOCIATED HEAVIEST RAINFALL EXITS STAGE RIGHT.
IN IT/S WAKE...WE CONTINUE TO BE AHEAD OF THE SURFACE BOUNDARY
THAT IS NOW REACHING GREEN BAY WITH IT/S SIGHTS ON NORTHERN
MICHIGAN OVERNIGHT. BETWEEN THESE TWO FEATURES...HAVE SEEN A FEW
SHOWERS BUBBLE UP...AND EXPECT THAT THIS WILL REMAIN THE CASE
UNTIL FROPA...SO WILL TREND POPS TO SCATTERED THROUGH
MIDNIGHT...BUT LINGER THEM THROUGH MUCH OF THE NIGHT /PARTICULARLY
OVER MY SOUTHEASTERN ZONES.
WILL ADD FOG TO THE GOING FORECAST AFTER MIDNIGHT AS WELL AS
UPSTREAM FOG PRODUCT IMAGERY SUGGESTS THE POTENTIAL FOR AT LEAST A
TEMPORARY THINNING/BREAK IN THE CLOUDINESS...WHICH WITH THIS
EVENING/S RAIN AND CURRENT 0-2F SURFACE DEWPOINT DEPRESSIONS...
WILL LIKELY ALLOW SOME FOG TO GET GOING...BUT LIKELY NOT GET TOO
OUT OF HAND GIVEN LOW STRATUS THAT LOOKS TO ARRIVE SHORTLY BEHIND
THE SURFACE COLD FRONT.
TEMPERATURE TRENDS HAVE BEEN ADJUSTED...BUT INHERITED LOWS RANGING
FROM THE LOWER 50S OVER EASTERN UPPER...TO THE LOWER 60S OVER
NORTHEAST LOWER STILL LOOK RIGHT ON TRACK.
UPDATE ISSUED AT 616 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: GOING FORECAST DOING JUST FINE AS OF THIS
WRITING...WITH SOME COSMETIC ADJUSTMENTS TO POPS/WEATHER AS RAIN
HAS JUST ABOUT REACHED THE ENTIRE FORECAST AREA. TEMPS HAVE FALLEN
NICELY WITH ARRIVAL OF RAINFALL..SO HAVE TRENDED NEAR TERM
TEMPERATURES DOWN AS WELL.
SEVERE THREAT HAS PRETTY MUCH ENDED WITH MUCAPES DROPPING CWA-WIDE
OVER THE PAST 3 HOURS. LIGHTNING STRIKES ARE FOLLOWING SUIT AS OF
THIS WRITING...BUT SOME EMBEDDED THUNDER CERTAINLY LIKELY THROUGH
THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
SHOWERS AND STORMS ON THE UPSWING THIS AFTERNOON ACROSS THE NORTH
WOODS. WATER VAPOR DEFINITELY HELPS EXPLAIN PART OF THE REASON...WITH
AN UNSEASONABLY STRONG SHORTWAVE TROUGH GOING NEGATIVE TILT BACK
ACROSS THE WESTERN LAKES. NICE MID LEVEL SPEED MAX ALSO NOTED...WITH
CORE OF 50+ KNOT H5 WINDS ROUNDING BASE OF TROUGH INTO SOUTHWEST
WISCONSIN. DEEP LAYER DYNAMICS INTERACTING WITH IN-PLACE RESPECTABLY
MOIST AIRMASS (PWAT VALUES PER RAP GUIDANCE NEAR 1.5 INCHES) HELPING
INDUCE CONVECTIVE DEVELOPMENT. MAIN LINE OF STORMS TIED TO
WISCONSIN/CENTRAL UPPER MICHIGAN COLD FRONT/FRONTAL WAVE WHERE LOW
LEVEL CONVERGENCE/DEEP LAYER DYNAMICS ARE BETTER JUXTAPOSED. MORE
SCATTERED SHOWERS AND STORMS BREAKING OUT ACROSS NORTHERN MICHIGAN
AS SUFFICIENT ML CAPE DEVELOPMENT (UPWARDS OF 500 J/KG) AND OBVIOUS
COOLING OF EARLIER H8-H7 WARM NOSE HAS TIPPED THE SCALE TO MOIST
CONVECTIVE DEVELOPMENT. SO FAR...THINGS HAVE BEEN BEHAVING
THEMSELVES...WITH JUST SOME LOCALLY HEAVY RAIN UNDER THE HEAVIER
CELLS. APPEARS A MUCH NEEDED WIDESPREAD RAIN IS IN THE OFFING THIS
EVENING AS ABOVE DYNAMICS/MOISTURE AXIS SPREAD EAST. FORECAST
CONCERNS CENTER ON SUCH...SPECIFICALLY TIMING OF SHOWERS AND STORMS
AND SEVERE WEATHER POTENTIAL.
UPSCALE GROWTH WILL CONTINUE WITH SHOWERS/STORMS AS DEEP LAYER
DYNAMICS ONLY INCREASE HEADING INTO LATER THIS AFTERNOON AND
EVENING. COLD FRONT EXPECTED TO GET THE BOOT EAST AS MID LEVEL
SUPPORT DOES THE SAME...AND WILL SIMPLY FOLLOW IT AND BEST UPWARD QG
SUPPORT FOR SHOWER/STORM TIMING. EXPECT ALL AREAS TO GET WET...WITH
THE HEAVIEST RAINS EXPECTED ACROSS FAR NORTHWEST LOWER AND EASTERN
UPPER (LOCAL AMOUNTS IN EXCESS OF AN INCH). MAIN LINE OF ACTIVITY
EXPECTED TO SWEEP EAST THIS EVENING...EXITING OFF THE SUNRISE SIDE
DURING THE EARLY MORNING. TEMPORAL DETAIL ACCOUNTS FOR SUCH...USING
CATEGORICAL COVERAGE FOR SPATIAL PURPOSES. NOT OVERLY ENTHUSED ABOUT
SEVERE POTENTIAL...WITH ML CAPE SOMEWHAT ON THE LEAN SIDE...AND
SHOULD CONTINUE TO REMAIN SO. DEEP LAYER EFFECTIVE SHEAR INCREASES
TO OVER 30 KNOTS...WITH 40 KNOT CORE SLIDING ACROSS EASTERN UPPER
LATE THIS AFTERNOON. CANNOT RULE OUT AN ISOLATED SEVERE WIND
GUST/MARGINALLY SEVERE HAILER WITH THE STRONGEST ACTIVITY...BUT A
WIDESPREAD SEVERE EVENT IS NOT EXPECTED. INTERESTINGLY...BACKED LAKE
INDUCED FLOW ACROSS THE TIP THE MITT/NORTHEAST LOWER/EASTERN UPPER
HAS RESULTED IN A TOUCH BETTER STORM ORGANIZATION WITH EVEN SOME
HINTS OF LOW-TOPPED SUPERCELLS. SPOTTER REPORTS NEGATIVE...
HOWEVER...WITH JUST LOCALLY HEAVY RAIN REPORTED WITH THESE CELLS.
WILL DEFINITELY CONTINUE TO MONITOR. POST-FRONTAL LOW LEVEL MOISTURE
SHOULD KEEP RATHER CLOUDY CONDITIONS THROUGH THE EARLY MORNING.
INITIAL SHOT OF CAA NOT OVERLY IMPRESSIVE...WITH LOWS BY SUN-UP
RANGING FROM THE 50S WEST...TO LOWER 60S ALONG NORTHEAST LOWER
COASTLINE.
DRY SLOT CONTINUES INTO SATURDAY MORNING AS MID LEVEL LOW PRESSURE
PINWHEELS INTO NORTHERN WISCONSIN. OFF THE DECK PROFILES REMAIN
RATHER DRY RIGHT THROUGH THE DAY...WITH DEEPER MOISTURE AXIS REMAIN
TO OUR WEST. CAA DROPS H8 TEMPERATURES INTO THE MID SINGLE
DIGITS...MORE THAN COLD ENOUGH TO ENTICE A LAKE RESPONSE (GULP!).
THAT SAID...NOT REALLY ENTHUSED ABOUT LAKE POTENTIAL...WITH DEEP
MOISTURE REMAINING UPSTREAM AND RATHER WEAK/DISORGANIZED LOW LEVEL
WIND FIELDS. MAY SEE SOME POP-UP ACTIVITY DURING THE AFTERNOON WITH
LAND MASS DESTABILIZATION...ESPECIALLY IF THE MORE AGGRESSIVE
NAM-WRF DEPICTIONS ARE REALIZED. HAVE TRENDED FORECAST HEAVILY IN
THIS DIRECTION...FOCUSING "BEST" SHOWER POTENTIAL TO
CLIMATOLOGICALLY FAVORED NORTHEAST LOWER WHERE LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED. THUNDER THREAT NOT INCLUDED...DISCOUNTING THE NAM
AT THIS TIME. LESS SHOWER ACTIVITY LIKELY TO RESULT IN SLIGHTLY WARMER
TEMPERATURES. HAVE NUDGED READINGS UP A FEW DEGREES ACROSS THE
BOARD...BUT NO DOUBT TEMPERATURES WILL BE SEVERAL DEGREES BELOW LATE
JULY NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
A RATHER BLOCKED LOOK REMAINS TO THE OVERALL HEMISPHERIC
PATTERN...WITH REX BLOCKING FOUND OVER THE NORTH CENTRAL
PACIFIC...AND A LARGE RIDGE OF HIGH PRESSURE FOUND AROUND IN THE
NORTH ATLANTIC /40W/. IN BETWEEN WE ARE LEFT WITH MEAN TROUGHING
OVER THE GREAT LAKES...WITH A VIGOROUS SHORTWAVE SEEN ON WATER VAPOR
IMAGERY DROPPING INTO THE UPPER MISSISSIPPI VALLEY THAT WILL HAVE
IMPLICATIONS FOR OUR WEEKEND WEATHER. LOOKING AHEAD...THE PATTERN
APPEARS TO BE VERY SLOW TO BREAK DOWN OVER THE NEXT SEVERAL
DAYS...WITH NORTH ATLANTIC HIGH PROGGED TO ACTUALLY RETROGRADE A BIT
BY EARLY NEXT WEEK...BEFORE SLOWLY BREAKING DOWN AND BECOMING
INCREASINGLY PROGRESSIVE LATER NEXT WEEK. THIS IDEA IS REFLECTED IN
THE LATEST NAO ENSEMBLE FORECASTS...MAINTAINING AN OVERALL NEGATIVE
PHASE/BLOCKED/COOLISH PATTERN UNTIL THE BEGINNING OF AUGUST BEFORE
TRENDING MORE NEUTRAL.
SATURDAY NIGHT INTO SUNDAY...MIGHT AS WELL RIP THE JULY AND AUGUST
PAGE RIGHT OFF THE CALENDAR...AS PATTERN FOR THE WEEKEND WILL BE
NOTHING SHORT OF FALL-LIKE. FIRST OFF..APPROACHING SHORT WAVE IS
SCHEDULED TO DROP INTO THE GREAT LAKES AND BECOME CLOSED OFF BY
SUNDAY AS A 555 DM LOW /YIKES!/. THE 500 MB HEIGHT ANOMALY IS AROUND
3 SD BELOW NORMAL FOR THIS TIME OF YEAR PER GEFS STANDARDIZED
ANOMALIES. CORE OF COLDEST AIR LOOKS TO PASS DIRECTLY OVER THE
CWA...WITH H85 TEMPS FALLING AOB 5C DURING THE DAY SUNDAY. BASED
ON PATTERN RECOGNITION AND ABUNDANCE OF H85-H7 MOISTURE PRESENT
DURING THE DAY ON SUNDAY...LOOKING LIKE A PRIME SETUP FOR SOME
INSTABILITY SHOWERS...ESPECIALLY DURING THE AFTERNOON IF WE CAN GET
JUST ENOUGH INSOLATION...DESPITE OVERALL CLOUDY LOOK TO THE
FORECAST. IN ADDITION...ANY SUBTLE VORT MAX ROUNDING MAIN LOW WILL
ALSO CREATE A THREAT FOR SHOWERS. REMOVED THUNDER FROM THE FORECAST
FOR INLAND SPOTS AS I AM NOT CONFIDENT THAT WE WILL HAVE SUFFICIENT
LAPSE RATES AND INSOLATION TO PRODUCE ANY APPRECIABLE CAPE AND
CONVECTIVE DEPTH TO PRODUCE THUNDER. COULD FORESEE SOME GRAUPEL
BEING MIXED GIVEN THE AMOUNT OF COLD AIR ALOFT...BUT TOO SOON TO
INCLUDE SUCH SMALL/MESOSCALE DETAILS IN THE FORECAST ATTM. HIGH
TEMPS ON SUNDAY WILL STRUGGLE TO BREAK THE 60 DEGREE MARK BASED ON
THIS VERY COOL PATTERN...AN KNOCKED OFF A DEGREE OR TWO FROM THE
INHERITED HIGH TEMPERATURES.
OF BIGGER CONCERN IS THE LAKE EFFECT RAIN POTENTIAL /YES...LAKE
EFFECT/...LAKE TEMPS IN THE MID TO UPPER 60S AND AFOREMENTIONED H85
TEMPS WILL CREATE DELTA T`S AROUND 13 TO 18C. THERE IS A DISCREPANCY
BETWEEN THE GUIDANCE OF THE MAIN 1000-850 MB FLOW SUNDAY
NIGHT...WITH THE GFS SUGGESTING MORE OF A SOUTHERLY FLOW FOR NW
LOWER...BUT THE CONSENSUS OFF THE NAM/GEM/ECMWF IS FOR A WEST TO
NORTHWEST ONSHORE WIND DIRECTION...ALBEIT FAIRLY LIGHT. WOULD NOT BE
SURPRISED TO SEE SOME LAKE EFFECT THUNDER WITH LAKE-INDUCED CAPE
VALUES HOVERING AROUND 750 J/KG BASED OFF NAM AND SREF BUFKIT
SOUNDINGS...AND LEFT SLT CHC THUNDER FOR LAKE EFFECT REGIONS THROUGH
SUNDAY. GIVEN THE STRONG INSTABILITY OVER THE LAKES WITH THE UPPER
LOW...ALSO LOOKING LAKE A GOOD SETUP FOR WATERSPOUTS OVER ALL OF THE
GREAT LAKES THROUGH SUNDAY.
SUNDAY NIGHT INTO MONDAY...THE UPPER LOW WILL BE SLOW TO MOVE OFF TO
THE EAST...ALONG WITH THE CORE OF DEEPEST MOISTURE AND BEST FORCING.
DELTA T`S WILL STILL REMAIN FAVORABLE FOR SOME LAKE EFFECT RAIN
SHOWERS FOR NORTHWEST LOWER...ALONG WITH WATERSPOUTS FOR THE GREAT
LAKES THROUGH SUNDAY NIGHT. DRIER MID LEVEL AIR WILL FILTER IN LATE
SUNDAY NIGHT INTO MONDAY...ALONG WITH WEAK SURFACE HIGH PRESSURE
SETTLING INTO THE WESTERN GREAT LAKES. SKIES WILL GRADUALLY CLEAR
FROM WEST TO EAST MONDAY...WITH HIGH TEMPERATURES EXPECTED TO
REBOUND INTO THE MIDDLE 60S TO NEAR 70...ASSUMING SUFFICIENT
SUNSHINE BY AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...CUTOFF LOW PROGGED TO BE CLEAR OF THE
REGION BY MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN THE GREAT
LAKES THROUGH TUESDAY NIGHT. SHORT WAVE RIDGING IS EXPECTED TO
SETTLE IN OVERHEAD UNDER A WEST NORTHWEST UPPER LEVEL FLOW REGIME.
THE REGION SHOULD SEE A GOOD DEAL OF SUNSHINE...WITH NEAR TO
SLIGHTLY BELOW NORMAL READINGS FOR TUESDAY ALONG WITH SOME COOL
NIGHTS EXPECTED MONDAY AND TUESDAY NIGHT. THE NEXT SHORTWAVE IN THE
WNW FLOW REGIME DROPS INTO THE GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY...AND THE ASSOCIATED LOW MOVING THROUGH SOUTHERN ONTARIO
WILL DRAG A COLD FRONT THROUGH THE CWA DURING THIS TIMEFRAME. THIS
WILL PROVIDE THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
REGION. A SECONDARY STRONGER SHORT WAVE LOOKS TO FOLLOW QUICK ON ITS
HEELS BY FRIDAY. ECMWF/GFS DIFFER ON THE TIMING AND PLACEMENT OF THE
SECOND WAVE...WITH THE NEW 12Z ECMWF SLOWER AND FURTHER NORTH WITH
THE WAVE. WILL HOLD OFF ADDING POPS FOR FRIDAY FOR NOW...AS I DON`T
WANT TO CLUTTER UP THE EXTENDED TOO MUCH WITH AN ALREADY FAIRLY BUSY
WEATHER PATTERN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 731 PM EDT FRI JUL 26 2013
SUMMARY: RAIN SHOWERS WILL CONTINUE AHEAD OF AN APPROACHING COLD
FRONT THIS EVENING BEFORE TAPERING OFF OVERNIGHT. LOW PRESSURE
WILL REMAIN OVER MICHIGAN THROUGH THE DAY ON SATURDAY...BRINGING
AN EXTENDED PERIOD OF POOR FLYING CONDITIONS.
RESTRICTIONS: SHOWERS BRINGING OCCASIONAL IFR VSBYS ATTM AND THIS
WILL CONTINUE OVER THE NEXT 1-3 HOURS...BEFORE THE SHOWERS BEGIN
TO PULL EAST AND WE BEGIN TO SEE MORE WIDESPREAD MVFR RESTRICTIONS
DUE TO CIGS...WITH PERHAPS SOME RESIDUAL LIGHT /MVFR/ FOG. TOWARDS
DAYBREAK...A PERIOD OF IFR CIGS LOOKS LIKE AT MBL/TVC/PLN BEFORE
GRADUAL IMPROVEMENT DURING THE DAY SATURDAY. THE EXCEPTION TO THIS
MAY BE APN WITH ANOTHER WAVE OF LOW PRESSURE TRACKING INTO LAKE
HURON IN THE AFTERNOON...WHICH MAY SPREAD RAIN BACK TOWARDS APN
DURING THE AFTERNOON. WILL KEEP THE TAF DRY IN THIS PACKAGE...BUT
MAINTAIN LOWER MVFR CIGS.
THUNDER: LIGHTNING STRIKES HAVE JUST ABOUT CEASED OVER THE PAST
HOUR...AND WHILE A FEW EMBEDDED RUMBLES ARE STILL POSSIBLE...
COVERAGE NOT HIGH ENOUGH TO WARRANT MENTION IN THIS TAF PACKAGE.
WINDS: CONVECTIVE OUTFLOW BOUNDARY AHEAD OF ARRIVING FRONT HAS
CAUSED SOME SHIFTING WINDS ALONG THE COAST OF NW LOWER...AND THIS
MAY BRING WINDS AT TVC/PLN TO NORTHWESTERLY FOR A TIME IN THE NEAR
TERM BEFORE WE AWAIT THE ACTUAL FRONTAL PASSAGE LATER THIS
EVENING. OUTSIDE OF THIS...EXPECT SOUTHWESTERLY WINDS TO GRADUALLY
VEER WESTERLY 5-10KTS OVERNIGHT AND THEN NORTHWESTERLY AROUND
10KTS BY SATURDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 415 PM EDT FRI JUL 26 2013
MARINE...GUSTY PRE-FRONTAL SOUTHWEST WINDS TO CONTINUE THROUGH THIS
AFTERNOON...MAINLY IMPACTING NORTHERN LAKE MICHIGAN. PRESSURE
GRADIENT SLACKENS OVERNIGHT...DESPITE COLD FRONTAL PASSAGE. GUSTY
THUNDERSTORM WINDS EXPECTED ALONG THIS FRONT...ESPECIALLY THIS
EVENING. MAINLY LIGHT WEST WINDS EXPECTED THROUGH THIS WEEKEND.
WATERSPOUT POTENTIAL WILL BE ON THE INCREASE THIS WEEKEND AS
UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE SLOWLY ROTATES ACROSS
THE NORTHERN LAKES. PERIODIC SHOWERS ALSO EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...NS
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
739 PM EDT FRI JUL 26 2013
.SYNOPSIS...
ISSUED AT 415 PM EDT FRI JUL 26 2013
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY ADVANCE
THROUGH THE STATE...TODAY THROUGH SATURDAY. THIS SYSTEM WILL PRODUCE
A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT...WITH THE
BULK OF THE RAINFALL OCCURRING LATE THIS AFTERNOON AND THIS EVENING.
RAIN MAY BE HEAVY AT TIMES...PARTICULARLY OVER THE EASTERN UPPER
PENINSULA.
BEHIND THE FRONT...SUBSTANTIALLY COOLER AIR WILL SETTLE INTO THE
GREAT LAKES FOR THE UPCOMING WEEKEND KNOCKING TEMPERATURES DOWN TO
WELL BELOW NORMAL READINGS FOR LATE JULY. THIS WILL LEAD TO
ADDITIONAL SHOWERS DEVELOPING ON SATURDAY AND PERSISTING THROUGH
SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 616 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: GOING FORECAST DOING JUST FINE AS OF THIS
WRITING...WITH SOME COSMETIC ADJUSTMENTS TO POPS/WEATHER AS RAIN
HAS JUST ABOUT REACHED THE ENTIRE FORECAST AREA. TEMPS HAVE FALLEN
NICELY WITH ARRIVAL OF RAINFALL..SO HAVE TRENDED NEAR TERM
TEMPERATURES DOWN AS WELL.
SEVERE THREAT HAS PRETTY MUCH ENDED WITH MUCAPES DROPPING CWA-WIDE
OVER THE PAST 3 HOURS. LIGHTNING STRIKES ARE FOLLOWING SUIT AS OF
THIS WRITING...BUT SOME EMBEDDED THUNDER CERTAINLY LIKELY THROUGH
THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
SHOWERS AND STORMS ON THE UPSWING THIS AFTERNOON ACROSS THE NORTH
WOODS. WATER VAPOR DEFINITELY HELPS EXPLAIN PART OF THE REASON...WITH
AN UNSEASONABLY STRONG SHORTWAVE TROUGH GOING NEGATIVE TILT BACK
ACROSS THE WESTERN LAKES. NICE MID LEVEL SPEED MAX ALSO NOTED...WITH
CORE OF 50+ KNOT H5 WINDS ROUNDING BASE OF TROUGH INTO SOUTHWEST
WISCONSIN. DEEP LAYER DYNAMICS INTERACTING WITH IN-PLACE RESPECTABLY
MOIST AIRMASS (PWAT VALUES PER RAP GUIDANCE NEAR 1.5 INCHES) HELPING
INDUCE CONVECTIVE DEVELOPMENT. MAIN LINE OF STORMS TIED TO
WISCONSIN/CENTRAL UPPER MICHIGAN COLD FRONT/FRONTAL WAVE WHERE LOW
LEVEL CONVERGENCE/DEEP LAYER DYNAMICS ARE BETTER JUXTAPOSED. MORE
SCATTERED SHOWERS AND STORMS BREAKING OUT ACROSS NORTHERN MICHIGAN
AS SUFFICIENT ML CAPE DEVELOPMENT (UPWARDS OF 500 J/KG) AND OBVIOUS
COOLING OF EARLIER H8-H7 WARM NOSE HAS TIPPED THE SCALE TO MOIST
CONVECTIVE DEVELOPMENT. SO FAR...THINGS HAVE BEEN BEHAVING
THEMSELVES...WITH JUST SOME LOCALLY HEAVY RAIN UNDER THE HEAVIER
CELLS. APPEARS A MUCH NEEDED WIDESPREAD RAIN IS IN THE OFFING THIS
EVENING AS ABOVE DYNAMICS/MOISTURE AXIS SPREAD EAST. FORECAST
CONCERNS CENTER ON SUCH...SPECIFICALLY TIMING OF SHOWERS AND STORMS
AND SEVERE WEATHER POTENTIAL.
UPSCALE GROWTH WILL CONTINUE WITH SHOWERS/STORMS AS DEEP LAYER
DYNAMICS ONLY INCREASE HEADING INTO LATER THIS AFTERNOON AND
EVENING. COLD FRONT EXPECTED TO GET THE BOOT EAST AS MID LEVEL
SUPPORT DOES THE SAME...AND WILL SIMPLY FOLLOW IT AND BEST UPWARD QG
SUPPORT FOR SHOWER/STORM TIMING. EXPECT ALL AREAS TO GET WET...WITH
THE HEAVIEST RAINS EXPECTED ACROSS FAR NORTHWEST LOWER AND EASTERN
UPPER (LOCAL AMOUNTS IN EXCESS OF AN INCH). MAIN LINE OF ACTIVITY
EXPECTED TO SWEEP EAST THIS EVENING...EXITING OFF THE SUNRISE SIDE
DURING THE EARLY MORNING. TEMPORAL DETAIL ACCOUNTS FOR SUCH...USING
CATEGORICAL COVERAGE FOR SPATIAL PURPOSES. NOT OVERLY ENTHUSED ABOUT
SEVERE POTENTIAL...WITH ML CAPE SOMEWHAT ON THE LEAN SIDE...AND
SHOULD CONTINUE TO REMAIN SO. DEEP LAYER EFFECTIVE SHEAR INCREASES
TO OVER 30 KNOTS...WITH 40 KNOT CORE SLIDING ACROSS EASTERN UPPER
LATE THIS AFTERNOON. CANNOT RULE OUT AN ISOLATED SEVERE WIND
GUST/MARGINALLY SEVERE HAILER WITH THE STRONGEST ACTIVITY...BUT A
WIDESPREAD SEVERE EVENT IS NOT EXPECTED. INTERESTINGLY...BACKED LAKE
INDUCED FLOW ACROSS THE TIP THE MITT/NORTHEAST LOWER/EASTERN UPPER
HAS RESULTED IN A TOUCH BETTER STORM ORGANIZATION WITH EVEN SOME
HINTS OF LOW-TOPPED SUPERCELLS. SPOTTER REPORTS NEGATIVE...
HOWEVER...WITH JUST LOCALLY HEAVY RAIN REPORTED WITH THESE CELLS.
WILL DEFINITELY CONTINUE TO MONITOR. POST-FRONTAL LOW LEVEL MOISTURE
SHOULD KEEP RATHER CLOUDY CONDITIONS THROUGH THE EARLY MORNING.
INITIAL SHOT OF CAA NOT OVERLY IMPRESSIVE...WITH LOWS BY SUN-UP
RANGING FROM THE 50S WEST...TO LOWER 60S ALONG NORTHEAST LOWER
COASTLINE.
DRY SLOT CONTINUES INTO SATURDAY MORNING AS MID LEVEL LOW PRESSURE
PINWHEELS INTO NORTHERN WISCONSIN. OFF THE DECK PROFILES REMAIN
RATHER DRY RIGHT THROUGH THE DAY...WITH DEEPER MOISTURE AXIS REMAIN
TO OUR WEST. CAA DROPS H8 TEMPERATURES INTO THE MID SINGLE
DIGITS...MORE THAN COLD ENOUGH TO ENTICE A LAKE RESPONSE (GULP!).
THAT SAID...NOT REALLY ENTHUSED ABOUT LAKE POTENTIAL...WITH DEEP
MOISTURE REMAINING UPSTREAM AND RATHER WEAK/DISORGANIZED LOW LEVEL
WIND FIELDS. MAY SEE SOME POP-UP ACTIVITY DURING THE AFTERNOON WITH
LAND MASS DESTABILIZATION...ESPECIALLY IF THE MORE AGGRESSIVE
NAM-WRF DEPICTIONS ARE REALIZED. HAVE TRENDED FORECAST HEAVILY IN
THIS DIRECTION...FOCUSING "BEST" SHOWER POTENTIAL TO
CLIMATOLOGICALLY FAVORED NORTHEAST LOWER WHERE LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED. THUNDER THREAT NOT INCLUDED...DISCOUNTING THE NAM
AT THIS TIME. LESS SHOWER ACTIVITY LIKELY TO RESULT IN SLIGHTLY WARMER
TEMPERATURES. HAVE NUDGED READINGS UP A FEW DEGREES ACROSS THE
BOARD...BUT NO DOUBT TEMPERATURES WILL BE SEVERAL DEGREES BELOW LATE
JULY NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
A RATHER BLOCKED LOOK REMAINS TO THE OVERALL HEMISPHERIC
PATTERN...WITH REX BLOCKING FOUND OVER THE NORTH CENTRAL
PACIFIC...AND A LARGE RIDGE OF HIGH PRESSURE FOUND AROUND IN THE
NORTH ATLANTIC /40W/. IN BETWEEN WE ARE LEFT WITH MEAN TROUGHING
OVER THE GREAT LAKES...WITH A VIGOROUS SHORTWAVE SEEN ON WATER VAPOR
IMAGERY DROPPING INTO THE UPPER MISSISSIPPI VALLEY THAT WILL HAVE
IMPLICATIONS FOR OUR WEEKEND WEATHER. LOOKING AHEAD...THE PATTERN
APPEARS TO BE VERY SLOW TO BREAK DOWN OVER THE NEXT SEVERAL
DAYS...WITH NORTH ATLANTIC HIGH PROGGED TO ACTUALLY RETROGRADE A BIT
BY EARLY NEXT WEEK...BEFORE SLOWLY BREAKING DOWN AND BECOMING
INCREASINGLY PROGRESSIVE LATER NEXT WEEK. THIS IDEA IS REFLECTED IN
THE LATEST NAO ENSEMBLE FORECASTS...MAINTAINING AN OVERALL NEGATIVE
PHASE/BLOCKED/COOLISH PATTERN UNTIL THE BEGINNING OF AUGUST BEFORE
TRENDING MORE NEUTRAL.
SATURDAY NIGHT INTO SUNDAY...MIGHT AS WELL RIP THE JULY AND AUGUST
PAGE RIGHT OFF THE CALENDAR...AS PATTERN FOR THE WEEKEND WILL BE
NOTHING SHORT OF FALL-LIKE. FIRST OFF..APPROACHING SHORT WAVE IS
SCHEDULED TO DROP INTO THE GREAT LAKES AND BECOME CLOSED OFF BY
SUNDAY AS A 555 DM LOW /YIKES!/. THE 500 MB HEIGHT ANOMALY IS AROUND
3 SD BELOW NORMAL FOR THIS TIME OF YEAR PER GEFS STANDARDIZED
ANOMALIES. CORE OF COLDEST AIR LOOKS TO PASS DIRECTLY OVER THE
CWA...WITH H85 TEMPS FALLING AOB 5C DURING THE DAY SUNDAY. BASED
ON PATTERN RECOGNITION AND ABUNDANCE OF H85-H7 MOISTURE PRESENT
DURING THE DAY ON SUNDAY...LOOKING LIKE A PRIME SETUP FOR SOME
INSTABILITY SHOWERS...ESPECIALLY DURING THE AFTERNOON IF WE CAN GET
JUST ENOUGH INSOLATION...DESPITE OVERALL CLOUDY LOOK TO THE
FORECAST. IN ADDITION...ANY SUBTLE VORT MAX ROUNDING MAIN LOW WILL
ALSO CREATE A THREAT FOR SHOWERS. REMOVED THUNDER FROM THE FORECAST
FOR INLAND SPOTS AS I AM NOT CONFIDENT THAT WE WILL HAVE SUFFICIENT
LAPSE RATES AND INSOLATION TO PRODUCE ANY APPRECIABLE CAPE AND
CONVECTIVE DEPTH TO PRODUCE THUNDER. COULD FORESEE SOME GRAUPEL
BEING MIXED GIVEN THE AMOUNT OF COLD AIR ALOFT...BUT TOO SOON TO
INCLUDE SUCH SMALL/MESOSCALE DETAILS IN THE FORECAST ATTM. HIGH
TEMPS ON SUNDAY WILL STRUGGLE TO BREAK THE 60 DEGREE MARK BASED ON
THIS VERY COOL PATTERN...AN KNOCKED OFF A DEGREE OR TWO FROM THE
INHERITED HIGH TEMPERATURES.
OF BIGGER CONCERN IS THE LAKE EFFECT RAIN POTENTIAL /YES...LAKE
EFFECT/...LAKE TEMPS IN THE MID TO UPPER 60S AND AFOREMENTIONED H85
TEMPS WILL CREATE DELTA T`S AROUND 13 TO 18C. THERE IS A DISCREPANCY
BETWEEN THE GUIDANCE OF THE MAIN 1000-850 MB FLOW SUNDAY
NIGHT...WITH THE GFS SUGGESTING MORE OF A SOUTHERLY FLOW FOR NW
LOWER...BUT THE CONSENSUS OFF THE NAM/GEM/ECMWF IS FOR A WEST TO
NORTHWEST ONSHORE WIND DIRECTION...ALBEIT FAIRLY LIGHT. WOULD NOT BE
SURPRISED TO SEE SOME LAKE EFFECT THUNDER WITH LAKE-INDUCED CAPE
VALUES HOVERING AROUND 750 J/KG BASED OFF NAM AND SREF BUFKIT
SOUNDINGS...AND LEFT SLT CHC THUNDER FOR LAKE EFFECT REGIONS THROUGH
SUNDAY. GIVEN THE STRONG INSTABILITY OVER THE LAKES WITH THE UPPER
LOW...ALSO LOOKING LAKE A GOOD SETUP FOR WATERSPOUTS OVER ALL OF THE
GREAT LAKES THROUGH SUNDAY.
SUNDAY NIGHT INTO MONDAY...THE UPPER LOW WILL BE SLOW TO MOVE OFF TO
THE EAST...ALONG WITH THE CORE OF DEEPEST MOISTURE AND BEST FORCING.
DELTA T`S WILL STILL REMAIN FAVORABLE FOR SOME LAKE EFFECT RAIN
SHOWERS FOR NORTHWEST LOWER...ALONG WITH WATERSPOUTS FOR THE GREAT
LAKES THROUGH SUNDAY NIGHT. DRIER MID LEVEL AIR WILL FILTER IN LATE
SUNDAY NIGHT INTO MONDAY...ALONG WITH WEAK SURFACE HIGH PRESSURE
SETTLING INTO THE WESTERN GREAT LAKES. SKIES WILL GRADUALLY CLEAR
FROM WEST TO EAST MONDAY...WITH HIGH TEMPERATURES EXPECTED TO
REBOUND INTO THE MIDDLE 60S TO NEAR 70...ASSUMING SUFFICIENT
SUNSHINE BY AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...CUTOFF LOW PROGGED TO BE CLEAR OF THE
REGION BY MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN THE GREAT
LAKES THROUGH TUESDAY NIGHT. SHORT WAVE RIDGING IS EXPECTED TO
SETTLE IN OVERHEAD UNDER A WEST NORTHWEST UPPER LEVEL FLOW REGIME.
THE REGION SHOULD SEE A GOOD DEAL OF SUNSHINE...WITH NEAR TO
SLIGHTLY BELOW NORMAL READINGS FOR TUESDAY ALONG WITH SOME COOL
NIGHTS EXPECTED MONDAY AND TUESDAY NIGHT. THE NEXT SHORTWAVE IN THE
WNW FLOW REGIME DROPS INTO THE GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY...AND THE ASSOCIATED LOW MOVING THROUGH SOUTHERN ONTARIO
WILL DRAG A COLD FRONT THROUGH THE CWA DURING THIS TIMEFRAME. THIS
WILL PROVIDE THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
REGION. A SECONDARY STRONGER SHORT WAVE LOOKS TO FOLLOW QUICK ON ITS
HEELS BY FRIDAY. ECMWF/GFS DIFFER ON THE TIMING AND PLACEMENT OF THE
SECOND WAVE...WITH THE NEW 12Z ECMWF SLOWER AND FURTHER NORTH WITH
THE WAVE. WILL HOLD OFF ADDING POPS FOR FRIDAY FOR NOW...AS I DON`T
WANT TO CLUTTER UP THE EXTENDED TOO MUCH WITH AN ALREADY FAIRLY BUSY
WEATHER PATTERN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 731 PM EDT FRI JUL 26 2013
SUMMARY: RAIN SHOWERS WILL CONTINUE AHEAD OF AN APPROACHING COLD
FRONT THIS EVENING BEFORE TAPERING OFF OVERNIGHT. LOW PRESSURE
WILL REMAIN OVER MICHIGAN THROUGH THE DAY ON SATURDAY...BRINGING
AN EXTENDED PERIOD OF POOR FLYING CONDITIONS.
RESTRICTIONS: SHOWERS BRINGING OCCASIONAL IFR VSBYS ATTM AND THIS
WILL CONTINUE OVER THE NEXT 1-3 HOURS...BEFORE THE SHOWERS BEGIN
TO PULL EAST AND WE BEGIN TO SEE MORE WIDESPREAD MVFR RESTRICTIONS
DUE TO CIGS...WITH PERHAPS SOME RESIDUAL LIGHT /MVFR/ FOG. TOWARDS
DAYBREAK...A PERIOD OF IFR CIGS LOOKS LIKE AT MBL/TVC/PLN BEFORE
GRADUAL IMPROVEMENT DURING THE DAY SATURDAY. THE EXCEPTION TO THIS
MAY BE APN WITH ANOTHER WAVE OF LOW PRESSURE TRACKING INTO LAKE
HURON IN THE AFTERNOON...WHICH MAY SPREAD RAIN BACK TOWARDS APN
DURING THE AFTERNOON. WILL KEEP THE TAF DRY IN THIS PACKAGE...BUT
MAINTAIN LOWER MVFR CIGS.
THUNDER: LIGHTNING STRIKES HAVE JUST ABOUT CEASED OVER THE PAST
HOUR...AND WHILE A FEW EMBEDDED RUMBLES ARE STILL POSSIBLE...
COVERAGE NOT HIGH ENOUGH TO WARRANT MENTION IN THIS TAF PACKAGE.
WINDS: CONVECTIVE OUTFLOW BOUNDARY AHEAD OF ARRIVING FRONT HAS
CAUSED SOME SHIFTING WINDS ALONG THE COAST OF NW LOWER...AND THIS
MAY BRING WINDS AT TVC/PLN TO NORTHWESTERLY FOR A TIME IN THE NEAR
TERM BEFORE WE AWAIT THE ACTUAL FRONTAL PASSAGE LATER THIS
EVENING. OUTSIDE OF THIS...EXPECT SOUTHWESTERLY WINDS TO GRADUALLY
VEER WESTERLY 5-10KTS OVERNIGHT AND THEN NORTHWESTERLY AROUND
10KTS BY SATURDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 415 PM EDT FRI JUL 26 2013
MARINE...GUSTY PRE-FRONTAL SOUTHWEST WINDS TO CONTINUE THROUGH THIS
AFTERNOON...MAINLY IMPACTING NORTHERN LAKE MICHIGAN. PRESSURE
GRADIENT SLACKENS OVERNIGHT...DESPITE COLD FRONTAL PASSAGE. GUSTY
THUNDERSTORM WINDS EXPECTED ALONG THIS FRONT...ESPECIALLY THIS
EVENING. MAINLY LIGHT WEST WINDS EXPECTED THROUGH THIS WEEKEND.
WATERSPOUT POTENTIAL WILL BE ON THE INCREASE THIS WEEKEND AS
UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE SLOWLY ROTATES ACROSS
THE NORTHERN LAKES. PERIODIC SHOWERS ALSO EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...NS
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EDT THU JUL 25 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW NW FLOW INTO THE UPPER
GREAT LAKES...RESULTING FROM A RIDGE OVER WRN N AMERICA AND A TROF
OVER ERN NAMERICA. WEAK REMNANT OF SHORTWAVE THAT WAS OVER CNTRL
SASKATCHEWAN 24HRS AGO IS NOW PASSING OVER THE UPPER GREAT LAKES.
12Z KINL SOUNDING SHOWED A CAP AROUND 12.5KFT MSL...AND LATEST SPC
ANALYSIS SHOWS MUCAPE ONLY 100-200J/KG. BOTH DO NOT SUPPORT MUCH OF
A SHRA POTENTIAL. KMQT RADAR IS OUT OF SERVICE UNTIL LATE THU
MORNING/EARLY AFTN WHILE PARTS ARE IN TRANSIT...SO NOT CERTAIN IF
THERE HAS BEEN ANY SHRA OVER W OR CNTRL UPPER MI THIS AFTN. HOWEVER...
KGRB/KDLH RADARS HAVE INDICATED A FEW RETURNS...SO THERE MIGHT BE A
FEW SPRINKLES OR PERHAPS A -SHRA OUT THERE. UPSTREAM...ISOLD/SCT
CONVECTION IS NOTED NW AND N OF LAKE SUPERIOR...TYPICAL FOR
SUMMERTIME NW FLOW. FARTHER UPSTREAM...A LARGER SCALE TROF EXTENDING
FROM WRN HUDSON BAY TO NRN ALBERTA IS DROPPING S. THIS FEATURE WILL
BE THE PLAYER IN THE WEATHER HERE THU THRU SAT.
WITH LOSS OF DAYTIME HEATING...ANY ONGOING ISOLD SHRA/SPRINKLES
WILL DISSIPATE THIS EVENING. HOWEVER...ANOTHER SUBTLE SHORTWAVE IS
NOTED OVER SRN MANITOBA...AND IT IS SUPPORTING MUCH OF THE ISOLD/SCT
SHRA/TSRA ACTIVITY OVER SE MANITOBA INTO ADJACENT NRN ONTARIO/NRN
MN. THIS WAVE COMBINED WITH WAA REGIME COULD HELP MAINTAIN A FEW
SHRA/POSSIBLE TSRA THRU THE NIGHTTIME HRS AS IT CONTINUES TO THE SE.
SO...WILL INCLUDE SCHC POPS OVER THE W LATE IN THE NIGHT.
ON THU...AFOREMENTIONED LARGER SCALE TROF WILL PIVOT SE INTO NRN
ONTARIO AND SRN MANITOBA/SRN SASKATCHEWAN. ASSOCIATED BROAD...BUT
ORGANIZING SFC LOW WILL REACH VCNTY OF WRN LAKE SUPERIOR LATE IN THE
DAY. THERE MAY BE A FEW SHRA/PERHAPS TSRA DURING THE MORNING HRS
WITHIN WAA REGIME. OTHERWISE...BUILDING INSTABILITY IN THE AFTN AND
APPROACHING HEIGHT FALLS AS LARGER SCALE TROF SWINGS CLOSER WILL
LIKELY RESULT IN INCREASING COVERAGE OF SHRA/TSRA DURING THE DAY.
WITH NAM/GFS MLCAPE INCREASING TO UPWARDS OF 1000J/KG AND DEEP LAYER
SHEAR PROGGED AT 30-40KT...EXPECT SOME STORM ORGANIZATION...LEADING
TO THE POSSIBILITY OF A FEW STRONGER STORMS. IF THERE IS SUFFICIENT
DAYTIME HEATING TO RAISE CAPE TO THE MODEL VALUES...THEN THERE WILL
BE THE POTENTIAL FOR ISOLD SVR STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
A LINE OF SHOWERS AND THUNDERSTORMS WILL BE MOVING ACROSS THE AREA
AT THE START OF THE LONG TERM PERIOD. THIS IS DUE TO A TROUGH
DIGGING SOUTHEAST INTO NORTHERN MINNESOTA AND PRODUCING A
BROAD/WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. THE GENERAL
TREND OVER THE LAST COUPLE OF DAYS IS FOR THE SHORTWAVE AND LOW
TRACK TO BE FARTHER SOUTH...WHICH INFLUENCES THE WEATHER FOR THE
WEEKEND. BEFORE THAT...THE SHOWERS AND THUNDERSTORMS WILL BE MOVING
EAST ACROSS CENTRAL AND EASTERN UPPER MICHIGAN DURING THE EVENING
AND INTO THE OVERNIGHT HOURS. WITH LIMITED INSTABILITY AND LOSS
OF DIURNAL HEATING...THINK THE SEVERE POTENTIAL IS MARGINAL EVEN
THOUGH 0-6KM SHEAR VALUES ARE IN THE 35-40KT RANGE. AS THE FIRST
WAVE OF PRECIPITATION MOVES EAST...THINK THERE WILL BE LINGERING
CLOUDS AND A FEW RAIN SHOWERS OVER THE WEST THROUGH THE NIGHT WITH
THE BROAD/WEAK LOW MOVING OVER THE WESTERN U.P.
SECOND SHORTWAVE WILL ARRIVE ON FRIDAY (WEST MORNING AND EAST
AFTERNOON) AND KICK OFF ANOTHER PERIOD OF NUMEROUS SHOWERS. SINCE
THE LOW WILL HAVE SHIFTED TOWARDS CENTRAL UPPER MICHIGAN...ANY
INSTABILITY (MUCAPE VALUES UNDER 750 J/KG) WILL BE ALIGNED ALONG AND
EAST OF THAT LOCATIONS...SO WILL CONFINE THE BEST THUNDER CHANCES
THERE. SINCE 0-6KM SHEAR VALUES ARE ONLY 15-20KTS...HEAVY RAIN
WOULD BE THE MAIN THREAT.
THIS SECOND SHORTWAVE WILL ALSO CAUSE THE TROUGH TO WRAP UP INTO A
CLOSED LOW OVER THE UPPER GREAT LAKES ON FRIDAY NIGHT AND REMAIN
IN THE AREA INTO SUNDAY MORNING. THIS WILL LEAD TO WEATHER MORE
LIKE LATE SEPTEMBER INSTEAD OF LATE JULY. DURING THAT
TIME...EMBEDDED WAVES AND INCREASED MOISTURE WILL LEAD TO CLOUDY
CONDITIONS...PERIODS OF RAIN (ESPECIALLY OVER THE NORTH
HALF)...GUSTY NORTHWEST WINDS (FRIDAY NIGHT INTO
SATURDAY EVENING)...AND TEMPERATURES WELL BELOW NORMAL (50S AND
LOW 60S SATURDAY). TEMPERATURES ON SATURDAY MAY BE SOMETHING TO
KEEP AN EYE ON...SINCE SOME OF THE RAW MODELS ARE INDICATING HIGHS
IN THE UPPER 40S OR LOW 50S OVER THE NORTHWEST HALF OF THE U.P.
LOOKING AT SOME PAST HIGHS...THE RECORD COLDEST JULY HIGH
TEMPERATURES FOR MANY SITES ARE IN THAT RANGE (NWS MQT 51 IN
2004/1992...CMX 49 IN 1992...IRONWOOD 52 IN 2009/1997).
MOST LIKELY PERIOD FOR DRIER WEATHER WILL BE SUNDAY AFTERNOON INTO
MONDAY AFTERNOON...AS THE UPPER LOW SHIFTS NORTHEAST INTO QUEBEC
AND WEAK HIGH PRESSURE SLIDES ACROSS THE AREA. MODELS CONTINUES TO
STRUGGLE ON THAT TIMING WITH THE SPEED OF THE UPPER LOW
EXITING...WHICH IS USUALLY THE CASE. ONCE THE LOW SHIFTS
NORTHEAST...A SERIES OF SHORTWAVES LOOK TO MOVE ACROSS THE UPPER
GREAT LAKES MONDAY NIGHT INTO TUESDAY NIGHT. WILL CONTINUE TO
MENTION LOW END CHANCE POPS FOR THESE SHORTWAVES MOVING THROUGH.
AFTER THE COOL WEEKEND...TEMPERATURES SHOULD REBOUND TO MORE NORMAL
VALUES FOR THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1210 AM EDT THU JUL 25 2013
EXPECT VFR CONDITIONS/DRY WX EARLY THIS MRNG BEFORE THE APPROACH OF
A LO PRES TROF BRINGS THE THREAT OF SOME SHRA AT THE WESTERN SITES
TOWARD SUNRISE. A BETTER CHC FOR THE SHRA AND SOME TS WL BE AFT
18Z...WHEN DAYTIME HEATING WL INCRS INSTABILITY. THE BEST
OPPORTUNITY FOR THE TS WL BE AT SAW...WHERE LLVL MSTR SURGE IS IN
BETTER SYNC WITH THE DYNAMIC SUPPORT AND DAYTIME HEATING. WITH MORE
OPPORTUNITY FOR SOME COOLING OFF LK SUP...THE CHC FOR TS IS LOWEST
AT CMX. SINCE THE LLVLS WL BE FAIRLY DRY...VFR CONDITIONS SHOULD
PREVAIL THRU THE DAY...BUT LOWER CONDITIONS COULD OCCUR UNDER THE
HEAVIER SHRA/TS. SOME LO CLDS COULD IMPACT CMX IN THE EVNG FOLLOWING
THE LOSS OF DAYTIME HEATING AND WITH AN INFLUX OF SOME LK COOLED AIR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT WED JUL 24 2013
WITH HIGH PRES DEPARTING TO THE E AND LOW PRES APPROACHING FROM THE
NW...S WINDS WILL BE THE RULE TONIGHT AND THU...THOUGH SPEEDS SHOULD
REMAIN UNDER 20KT. IF THERE ARE ANY STRONGER WINDS...THEY WILL OCCUR
OVER ERN LAKE SUPERIOR THU AFTN/EVENING. ONCE THE LOW MOVES E OF
LAKE SUPERIOR...WINDS WILL SHIFT AROUND TO THE N TO NW FRI. GIVEN
THE INCOMING CHILLY AIR MASS FOR THIS TIME OF YEAR...IT LOOKS LIKE
THERE WILL BE A PERIOD OF 15-25KT WINDS OVER MAINLY CNTRL LAKE
SUPERIOR FRI NIGHT INTO SAT. HOWEVER...IT`S NOT OUT OF THE QUESTION
THAT WINDS COULD BE HIGHER DUE TO THE UNSEASONABLY COOL AIR MASS
PUSHING OVER THE AREA. WINDS WILL DIMINISH SUN/MON AS HIGH PRES
BUILDS INTO THE WRN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1142 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIME-FRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEW-POINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1127 AM CDT THU JUL 25 2013
MAIN AVIATION CONCERN IS COVERAGE OF THE SHRA/TSRA THIS AFTN ONCE
THE CAP BREAKS AND AN AREA OF SHRA/TSRA BETWEEN TWO SYSTEMS ACROSS
SD/WC MN BEGIN TO MERGE. INITIALLY...IT SEEMS THAT THE BEST
MOISTURE CONVERGENCE WILL BE SOUTH OF THE MAIN MPX TAF
TERMINALS...WITH THE EXCEPTION OF RWF/EAU WHERE DAYTIME HEATING
AND A MORE SW FLOW WILL AID IS BETTER TSRA ACTIVITY AND COVERAGE.
ELSEWHERE...ESPECIALLY NORTH OF MSP TO RNH...ACTIVITY WILL LIKELY
BE ISOLATED IN TERMS OF TSRA WITH MORE SHRA DURING THE FIRST 3-6
HRS. ONCE THE MAIN CAA BEGINS THIS AFTN ACROSS WC MN...THE
SHRA/TSRA ACTIVITY SHOULD MOVE SOUTH ACROSS MOST OF MPX AIRPORT
TERMINALS. WILL CONTINUE WITH A TEMPORARY PERIOD OF 4-6SM SHRA
WITH VCTS AT RWF BETWEEN 18-20Z. THIS IS SIMILAR TO EAU BUT A BIT
LATER. AFT 06Z...MOST OF THE SHRA SHOULD BE SOUTH OF MN...BUT DO
HAVE SOME CONCERNS WITH REDEVELOPMENT OF -SHRA ALONG THE LEADING
EDGE OF THE STRONGEST CAA THIS EVENING. LATER SHIFTS WILL NEED TO
MONITOR ACTIVITY ACROSS NW MN AND WHETHER THIS WILL HOLD ON DURING
THE AFTN/EVENING. WINDS WILL INCREASE BY FRIDAY MORNING FROM THE
NW/NNW AND BECOME GUSTY BY 15-18Z. MVFR CIGS ARE ALSO LIKELY BY
9-15Z ACROSS AXN/STC/RNH.
KMSP...
THE NEXT 6 HRS FORECAST IS BASED ON ACTIVITY ACROSS WC MN AND
WHETHER THIS ACTIVITY WILL INTENSIFY...OR REDEVELOP FURTHER TO
THE SOUTH AND KEEP THE BULK OF THE HEAVIER TSRA SOUTH OF MSP
TERMINAL. THERE IS ENOUGH CERTAINTY THAT VCTS WILL OCCUR AT MSP.
TIMING AND HOW STRONG REMAINS THE PROBLEM. WILL CONTINUE WITH VCTS
BUT TEMPORARY OF 5-6SM SHRA AND CIGS DROPPING TO LOW END VFR. SOME
CONCERNS OF REDEVELOPMENT OF VCSH AFT 00Z WITH THE MAIN CAA
STARTS. BUT WILL LEAVE THIS ALONE FOR THE SHORT TERM. GUSTY WINDS
WILL LIKELY DEVELOP BY MID/LATE FRIDAY MORNING AS MUCH COOLER AIR
USHERS IN FOR LATE JULY. SOME MVFR CIGS ARE POSSIBLE DURING THE
MORNING...BUT NOT ENOUGH CONFIDENCE TO BEGIN WITH MVFR CIGS...BUT
KEEP SCT020 CIGS OF 3.5K REMAINING IN THE TAF.
/OUTLOOK FOR KMSP/
FRI EVENING...VFR. WINDS NW 15G25 KTS.
SAT...VFR. WINDS NW 10G20 KTS.
SUN...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
619 AM CDT THU JUL 25 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIMEFRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEWPOINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 619 AM CDT THU JUL 25 2013
STILL RATHER LOW CONFIDENCE IN TSRA FORECAST THIS AFTERNOON THANKS
TO COLD FRONT SLIPPING THROUGH BEING RATHER ILL-DEFINED. SEEING
QUITE A BIT OF VARIABILITY FROM HOUR TO HOUR FOR WHERE/WHEN THE
HRRR DEVELOPS STORMS...BUT THERE IS A TREND BETWEEN THE
HRRR...6Z HOPWRF AND 6Z NAM FOR ACTIVITY THIS AFTERNOON TO BE A
BIT FARTHER SOUTH THAN INITIALLY THOUGHT...POSSIBLY REMAINING
SOUTH OF ALL TERMINALS. STILL TO DIFFICULT TO PIN DOWN EVEN A 4
HOUR WINDOW FOR WHEN TSRA MAY OCCUR...SO CONTINUED TO PLAY THINGS
RATHER CONSERVATIVELY IN TAFS WITH VCSH GROUPS. LATE TONIGHT...CAA
WILL START TO INCREASE ACROSS CENTRAL MN...WITH THE NAM/GFS
HINTING AT SOME MVFR STRATOCU COMING DOWN WITH IT. FOR
WINDS...WEAK GRADIENT MEANS WEAK WINDS...WITH DIRECTIONS LIKELY
BOUNCING AROUND A BIT FROM THE NW TO SW. STRONG NW WINDS LOOK TO
HOLD OFF UNTIL FRIDAY MORNING/AFTERNOON.
KMSP...FAIRLY LOW CONFIDENCE IN TAF...WITH CURRENT TRENDS IN SHORT
TERM MODELS AND 6Z NAM GOING SOUTH OF THE FIELD WITH AFTERNOON
CONVECTION. CAN NOT RULE TSRA COMPLETELY...BUT STARTING TO LOOK
LIKE THE REST OF DAY MAY BE DRY. LATE TONIGHT INTO FRIDAY
MORNING...WILL LIKELY HAVE A BANK OF STRATOCU COMING DOWN WITH
SURGE OF COLD AIR WHICH MAY BRING MVFR CIGS IN FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS POSSIBLE. WINDS NW 15G25 KTS.
SAT...VFR. WINDS NW 10G20 KTS.
SUN...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
436 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIMEFRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEWPOINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 936 PM CDT WED JUL 24 2013
THINKING HASN/T CHANGED MUCH FROM PREVIOUS SET OF TAFS. THE MAIN
DIFFERENCE IS WITH THE ACTIVITY CURRENTLY MOVING INTO THE NORTHERN
PART OF THE FORECAST AREA... WHICH WAS A MILD CONCERN EARLIER.
IT IS LASTING LONGER THAN MUCAPE AND ANY LLJ FORCING WOULD
SUGGEST... SO MAY NEED TO ACCOUNT FOR IT AT AT LEAST KSTC.
HOWEVER... STILL WOULD EXPECT IT TO HAVE TROUBLE MOVING VERY FAR
EAST INTO MORE STABLE AIR. CONFIDENCE REMAINS FAIRLY LOW ON
TIMING/LOCATION OF SHRA/TSRA ON THURSDAY... ALTHOUGH THERE IS
STILL GOOD CONFIDENCE ON OCCURRENCE SOMEWHERE ACROSS THE AREA.
SO... CONTINUED TO MAINLY HIT CHANCES FOR EASTERN SITES... BUT NOT
GO TOO PESSIMISTIC WITH RESPECT TO FLIGHT CONDITIONS GIVEN LACK OF
CONFIDENCE OF WHEN/WHERE THINGS WILL OCCUR.
KMSP...TAF REFLECTS EXPECTATIONS WITH MAIN UNCERTAINTIES BEING
IF/WHEN SHRA/TSRA WILL OCCUR ON THURSDAY. IF WE DO SEE SOME STORMS
AT THE SITE... WE/LL MORE THAN LIKELY GET DOWN INTO MVFR FLIGHT
CONDITIONS. WILL STILL NEED TO KEEP AN EYE ON ACTIVITY CURRENTLY
TO THE NORTHWEST... WHICH IF IT SURVIVES WOULD ARRIVE SOMETIME
BEFORE 09Z. BUT... LEFT IT OUT FOR NOW WITH EXPECTATION IT WILL
WEAKEN.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR POSSIBLE WITH A CHANCE OF SHRA. NW WIND 10-20 KT.
FRI NIGHT...MVFR CIGS POSSIBLE...OTHERWISE VFR. NW WIND 5-15 KT.
SAT...VFR. NW WIND 10-20 KT.
SAT NIGHT...VFR EXPECTED. MVFR CIGS POSSIBLE. VRBL WIND LESS THAN
10 KT.
SUN...VFR EXPECTED. MVFR CIGS POSSIBLE EARLY. N WIND LESS THAN 10
KT BECOMING VRBL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
345 PM CDT Thu Jul 25 2013
.SHORT TERM...(This Evening through Friday)
Issued at 345 PM CDT THU JUL 25 2013
A weak short wave trough moving through the northwest flow will
bring a few showers and thunderstorms overnight. The main challenge
will be deciding how much of the area will stay intact as it moves
from Kansas and Nebraska towards Missouri. The HRRR is a little slow
but has the conceptual idea of pattern right so will follow that for
the first period. As the sun sets some of the convection may
diminish and most concentrated area will likely pass to the
southwest of the CWA anyway. Still, the NAM is showing some mid
level lapse rates around 6 K/KM and around 1.5 inches of
precipitable water over extreme eastern Kansas and western Missouri
with lower values to the east. Given the dry conditions at the
surface confidence is still fairly low for any widespread QPF
tonight.
Tomorrow...chances of precipitation will decreas across the area as
short wave trough exits that area. Still will be in northwest flow
and relative humidities drop through the day such that by evening
conditions should be cool and dry with light winds overnight.
Saturday will be picture perfect with low humidities and high
temperatures in the 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 345 PM CDT THU JUL 25 2013
For the last half of the forecast, below normal temperatures with a
decent chance at rain will be the dominate conditions. Pattern
across the country over the weekend will be dominated by a locally
northwest flow, within the larger amplified pattern in place
across the nation thanks to a cutoff low that will develop over the
Great Lakes this weekend. However, the low is not expected to hang
out for long as by late in the weekend it will have migrated far
enough to the northeast to allow the prevailing flow across the
Plains to return to a zonal pattern.
Over the later half of the weekend, temperatures will remain rather
cool for late July, with highs from the 70s into the 80s. These
pleasant conditions should persist into the work week even as the
zonal flow allows temperatures to moderate up some going into the
work week. Ultimately, the thermal ridge will remain to our west as
the flow adjusts through the beginning of the work week, thus
sparing the region from the oppressively hot temperatures more
typical of late July.
Otherwise, our precipitation chances for early in the work week are
looking rather decent, though persistence considerations leaves
confidence lower than the POPs advertised. As the pattern
flattens out across the nation Sunday night into Monday a shortwave
trough will shift across the center of the nation. Medium range
models have been keying on this shortwave for precipitation, though
the latest runs have slide the periods of focus for the storms from
Sunday night more fully into Monday and Tuesday over the last
several runs. Models continue to robustly advertise storms in these
early work week periods as isentropic lift and moisture transport
spread into Kansas and Missouri, therefore have kept going with
likely POPs for Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1230 PM CDT THU JUL 25 2013
A small cluster of showers with a few thunderstorms embedded will
move towards the terminals this afternoon. This area is about 50
miles wide at present and is mainly over Atchison and Jefferson
Counties in Kansas. The area may stay intact or weaken over the next
couple of hours as it moves towards KMCI. Therefore have put VCTS in
the TAFS beginning around 19 UTC for KMCI and KSTJ...and 20 UTC for KMKC.
Low confidence in the tempo group for this evening but with a weak
wave moving through and some modest instability and low level
moisture will go with tempo group until after sunset. Tomorrow
morning some of the guidance suggests some less than VFR conditions
but believe that the air will be drier behind the weak wave so will
keep a VFR deck in around 5000 feet.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Adolphson
LONG TERM...Cutter
AVIATION...Adolphson
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
655 AM CDT Thu Jul 25 2013
.SHORT TERM...(Today through Friday night)
Issued at 401 AM CDT THU JUL 25 2013
Dominant northwest flow pattern aloft will continue east of the
Rockies during this period. This pattern will continue to tease us
on rain potential as shortwave troughs and associated convection
roll out of the Northern and Central High Plains. Early this morning
is no different than the past couple of nights, except, dare I say,
this time it looks different. The initial activity fell apart over
southwest NE, however new convection formed over northwest KS and
appears to be holding its own as it tracks eastward. 06Z HRRR
reflectivity output and 06Z NAM/GFS/ECMWF are more supportive of
holding the precipitation together longer than previous features
rolling across KS/NE. However, convection will be heading into a
less favorable airmass which lies over MO so won`t get carried away
and spread PoPs too far into western MO until later tonight.
Models have also been consistent in developing a large MCS over KS
tonight and sliding it southeast, and yes once again bypassing most
of the CWA. However, believe there will be scattered convection
which forms further northeast over the CWA after midnight ahead of a
cold front dropping south across IA. Overall, tonight/Friday morning
will provide at least chance PoPs for everyone, although qpf amounts
will be rather puny except for the southern counties where deeper h8
moisture is expected to advect in from the southwest.
A pronounced upper trough will rotate southeast through the Upper MS
Valley tonight and into the Great Lakes on Friday. Models are all in
agreement that the upper trough will be deeper and track further
south than previous forecasts. This will drive a cold front
southward a bit faster. Any scattered shower activity ahead of the
front will be pushed aside by the passage of the front. High
pressure building in behind the front will draw abnormally cool air
southward Friday/Friday night. Have lowered Saturday morning lows by
3-5F with readings falling into the lower to middle 50s and
approaching the record low of 55 at MCI.
.LONG TERM...(Saturday through Wednesday)
Issued at 401 AM CDT THU JUL 25 2013
Saturday - Sunday:
Tranquil conditions are expected through the weekend as surface high
pressure builds in behind the cold front which passes through the
area on Friday. The area will be under cool northwest flow aloft on
the back side of an slow moving upper level trough moving through
the Great Lakes. This will allow for very pleasant and below average
high temperatures, ranging from the mid 70 to low 80s this weekend.
Sunday night - Tuesday night:
By the end of the weekend, the flow across the CONUS becomes
quasi-zonal as an upper level ridge out west over the weekend begins
to get flattened out by a series of shortwaves. The first of these
shortwaves is progged to reach the area by Sunday night/Monday
morning. Models continue to be consistent in advertising that these
shortwaves may lead to a prolonged period of precipitation chances.
The best chance for precipitation appears to be between Monday and
Tuesday and as such have higher end chance POPs through that period.
Precipitation will diminish Tuesday night as the shortwaves push
east. Temperatures Monday and Tuesday will continue to remain below
average with cloudy skies and precipitation chances. Highs Monday
and Tuesday will be in the upper 70s to mid 80s.
Wednesday:
Towards the end of the extended period the western ridge looks to
reassert itself. This will put the area back under northwest flow
aloft. Still can not rule out another shortwave moving through the
area but no confidence in timing and placement so have slights in
for Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 653 AM CDT THU JUL 25 2013...Corrected
VFR conditions expected through the forecast period, even if/when any
convection moves through the terminals.
Monitoring convective complex over north central KS closely as it
continues tracking east along and north of I-70. A short range
convective allowing model, HRRR, and now the 06Z GFS hold this
activity together through the morning and afternoon hours. They
bring active convection into all 3 terminals after 19Z. All other
models are dry over the 3 terminals until later this evening.
Similar activity over the past several mornings dissipated by the
time it reached far eastern KS. However, the HRRR has been accurate
the last several nights so will need to monitor radar and satellite
trends and amend if necessary.
Should the north central KS convection hold together and affect the
terminals this afternoon it will likely affect timing on any
additional storms which are expected to move into eastern KS and
western MO later tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
924 PM MDT FRI JUL 26 2013
.UPDATE...
JUST SOME MINOR TWEAKS THIS EVENING. LIGHT SHOWERS MAY SPREAD INTO
WESTERN ZONES THROUGH MIDNIGHT OR 100 AM. INVERTED V SOUNDINGS
FOR TOMORROW AND SREF PARAMETERS CONTINUE TO SUGGEST POTENTIAL FOR
DRY THUNDER TOMORROW...THEN WETTER WITH WIDER COVERAGE ON SUNDAY.
BT
&&
.SHORT TERM...VALID FOR SAT AND SUN...
THE BREAKDOWN OF THE NORTHERN ROCKIES UPPER-LEVEL RIDGE WILL YIELD
A RISK OF DRY THUNDERSTORMS IN SOUTH CENTRAL MT SATURDAY AFTERNOON
AND EVENING...BEFORE LOWERING HEIGHTS YIELD MORE WIDESPREAD SHOWER
AND STORM ACTIVITY OF A WET VARIETY OVER THE WHOLE AREA ON SUNDAY.
TONIGHT...WE LEFT SOME LOW POPS IN PLAY OVER SOUTH CENTRAL MT WITH
WEAK UPSLOPE FLOW. RECENT HRRR RUNS SUPPORT ISOLATED STORMS ACROSS
THAT AREA. OTHERWISE...WE WILL NEED TO KEEP AN EYE ON ANY SMALLER-
SCALE PERTURBATIONS IN NORTHWEST FLOW OVER SOUTHEASTERN MT IN CASE
THEY ARE ABLE TO GENERATE SOME PRECIPITATION...BUT FOR NOW WE LEFT
A DRY FORECAST IN PLACE THERE.
SAT...IT APPEARS THAT A COUPLE OF WEAK SHORT WAVES OBSERVED IN THE
FRIDAY AFTERNOON MOISTURE CHANNEL IMAGERY FROM NORTHERN CA INTO OR
WILL MOVE INTO SOUTH CENTRAL MT BY LATE IN THE DAY. MODEL GUIDANCE
HAS BEEN CONSISTENT IN ADVERTISING THIS EVOLUTION AS HEIGHTS ALOFT
START TO FALL BY LATE DAY...AND THAT SHOULD FOSTER SCATTERED STORM
ACTIVITY. FORECAST SOUNDINGS IN SOUTH CENTRAL MT STILL SHOW A WEAK
CAPE ENVIRONMENT...BUT STEEP LOW- AND MID-LEVEL LAPSE RATES WITH A
PLUME OF MID- AND HIGH-LEVEL MOISTURE WHICH IS FAVORABLE FOR HIGH-
BASED THUNDERSTORMS. COVERAGE WOULD ORDINARILY BE IN QUESTION WITH
MLCAPE LESS THAN 500 J/KG...AND IN SOME WAYS IT STILL IS...BUT THE
SYNOPTIC-SCALE ENVIRONMENT IS FAVORABLE FOR CONVECTION AND THAT IS
HELPING BUILD OUR CONFIDENCE IN STORM DEVELOPMENT. THE 09 UTC SREF
CALIBRATED DRY THUNDERSTORM PROBABILITIES HAVE RISEN SINCE THE RUN
FROM THAT TIME YESTERDAY /WHEN THEY WERE ALREADY NOTABLE/...AND SO
THERE IS STATISTICAL SUPPORT FOR THE THREAT OF DRY LIGHTNING WHICH
FORECAST SOUNDINGS IMPLY. PRECIPITABLE WATER VALUES WILL BE AROUND
0.75 INCHES...AND BOUNDARY LAYER HUMIDITIES WILL BE AT OR BELOW 20
PERCENT EVEN THOUGH HIGHS MAY ONLY BE AROUND 90 F. FIRE MANAGEMENT
OFFICIALS CONFIRM THAT FUELS OVER THE GALLATIN NATIONAL FOREST ARE
RECEPTIVE OF LIGHTNING AND SO NEW FIRE STARTS ARE A CONCERN. BASED
ON THAT RISK...WE ISSUED A FIRE WEATHER WATCH ACROSS THAT AREA AND
THE SWEET GRASS AND WHEATLAND COUNTY FIRE WEATHER ZONE FROM 18 UTC
THROUGH 06 UTC. PER DISCUSSION WITH FIRE MANAGEMENT OFFICIALS...WE
DID NOT CARRY THE HEADLINE EAST OF THAT AREA SINCE FUELS AREN/T AS
DRY. NOTE THAT THE INVERTED-V SOUNDING PROFILES ALSO SUPPORT GUSTY
AND ERRATIC OUTFLOW WIND GUSTS OF 50 MPH...AND A SEVERE-LEVEL WIND
EVENT IS NOT OUT OF THE QUESTION. ISOLATED CONVECTION MAY MAKE IT
INTO SOUTHEASTERN MT BY SAT NIGHT.
SUN...SOUTHWEST FLOW ALOFT SHOULD YIELD MORE WIDESPREAD CONVECTION
AS PRECIPITABLE WATER VALUES CLIMB TO AN INCH OR BETTER. THERE HAS
BEEN SOME CONSISTENCY IN MODEL SOLUTIONS IN SHOWING A MODEST FRONT
AND ASSOCIATED WIND SHIFT OVER SOUTHEASTERN MT...WHICH COULD FOCUS
ENOUGH STORMS TO GARNER LIKELY POPS WITH LATER FORECASTS. SUN WILL
ALSO BE COOLER BEHIND THAT FRONT. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED FORECAST IN
ADVERTISING A CHANGE TO UNSETTLED WEATHER AND NEAR SEASONAL
TEMPERATURES. UPPER LEVEL TROUGH OF LOW PRESSURE ALONG THE WEST
COAST WILL KEEP A SOUTHWEST TO WEST FLOW ACROSS OUR FORECAST AREA.
THIS WILL ENABLE A SERIES OF SHORT WAVES TO MOVE ACROSS SOUTHERN
MONTANA. THESE UPPER LEVEL SYSTEMS WILL BE ACCOMPANIED BY PACIFIC
MOISTURE. ADDITIONAL LOW LEVEL MOISTURE WILL BE ADVECTING INTO THE
REGION AS LOW PRESSURE OVER THE WEST COAST WILL MAINTAIN A WEAK
UPSLOPE FLOW ACROSS OUR REGION. HAVE CONTINUED SCATTERED POPS
THROUGH THE EXTENDED FORECAST WITH MODELS IN GOOD AGREEMENT. LOWER
HEIGHTS ACROSS THE AREA WILL RESULT IN TEMPERATURES AT OR SLIGHTLY
BELOW SEASONAL VALUES. HAVE MADE ONLY MINOR CHANGES TO
TEMPERATURE FORECAST. RICHMOND
&&
.AVIATION...
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DIMINISH
IN COVERAGE OVER THE HIGH TERRAIN THIS EVENING. OTHERWISE...VFR
CONDITIONS WILL PREVAIL OVER ALL ROUTES OVERNIGHT. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 058/090 063/082 061/080 058/085 059/086 061/084 060/084
22/T 32/T 43/T 32/T 33/T 33/T 33/T
LVM 055/093 054/083 052/079 049/085 051/085 052/081 051/080
23/T 32/T 33/T 23/T 33/T 32/T 33/T
HDN 057/091 060/085 059/082 058/086 059/086 060/085 060/085
12/T 33/T 44/T 32/T 23/T 33/T 33/T
MLS 055/086 062/086 062/082 060/085 060/086 062/085 062/085
11/U 24/T 54/T 33/T 33/T 33/T 33/T
4BQ 051/086 058/086 057/082 058/083 058/085 058/085 059/084
11/U 24/T 54/T 33/T 33/T 34/T 33/T
BHK 048/077 053/080 057/078 056/079 056/080 058/080 057/080
11/N 25/T 54/T 33/T 22/T 33/T 33/T
SHR 054/089 056/083 055/081 055/086 055/085 056/083 055/083
23/T 34/T 44/T 32/T 22/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FIRE WEATHER WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR ZONES 28-40-41-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1254 PM CDT THU JUL 25 2013
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
SURFACE COLD FRONT EXTENDING FROM SOUTHEASTERN SOUTH DAKOTA TO
CENTRAL NEBRASKA WILL CONTINUE TO DROP SOUTHEASTWARD THROUGH
EASTERN NEBRASKA THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO OCCUR ALONG AND AHEAD OF THE FRONT MAINLY AFTER
20Z TO 06Z ACROSS EASTERN NEBRASKA AND WESTERN IOWA. SOME STORMS
MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. MVFR CONDITIONS
ARE FORECAST IN SOME OF THE STORMS. VFR CONDITIONS ARE EXPECTED
AFTER FRONTAL PASSAGE AFTER 06 TO 09Z.
SMITH
&&
PREV DISCUSSION... /ISSUED 305 AM CDT THU JUL 25 2013/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
.AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
.BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
621 AM CDT THU JUL 25 2013
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
CHANCE FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON/EVENING IS THE
MAIN CONCERN. A LITTLE TOO LOW OF CONFIDENCE IN COVERAGE TO
INCLUDE A PREVAILING GROUP OR A THUNDER MENTION JUST YET...BUT DID
TEMPO IN A SHOWER MENTION AT ALL SITES FOR THE MOST LIKELY TIME
WINDOW FOR SHOWERS. THOUGH TEMPO GROUP KEEPS VFR CEILINGS AND
VISIBILITY...HEAVIER SHOWERS COULD LOWER VISIBLITIES BRIEFLY TO
MVFR OR EVEN IFR. SOUTH WINDS SHOULD DOMINATE THIS
AFTERNOON...WITH SPEEDS INCREASING BY MIDDAY. BEHIND THE
FRONT...WINDS SHOULD INCREASE OUT OF THE NORTHWEST. SOME MODELS
HINT AT RESTRICTED VISIBILITY OR CEILINGS...BUT THIS IS LATE IN
THE PERIOD...AND HAVE KEPT MENTIONS ABOVE VFR THRESHOLDS FOR NOW
UNTIL CONFIDENCE INCREASES.
MAYES
&&
.PREV DISCUSSION... /ISSUED 305 AM CDT THU JUL 25 2013/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
..AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
..BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
305 AM CDT THU JUL 25 2013
.DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
...AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
...BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS EXPECTED FOR MOST OF THE PERIOD WITH BKN-OVC
HIGH CLOUDS. MVFR CIGS AND VSBYS IN THUNDERSTORMS POSSIBLE AFTER
18Z AS COLD FRONT MOVES INTO THE AREA...BUT NOT IN FORECAST AT
THIS TIME DUE TO TIMING UNCERTAINTY.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
321 PM MDT THU JUL 25 2013
.DISCUSSION...ENHANCED NW TO SE STEERING FLOW IN PLACE ACROSS ROUGHLY
THE NE HALF OF THE FORECAST AREA TODAY RESULTING IN MUCH FASTER
STORM MOTIONS BUT ALSO GREATER STORM ORGANIZATION/STRUCTURE. THE
SW HALF CONTINUES UNDER THE INFLUENCE OF AN UPPER LEVEL COL REGION
BETWEEN TWO HIGH CENTERS...PRIMARY ONE OVER NW AZ AND A SECONDARY
CENTROID WEST OF THE TX BIG BEND REGION. AT LEAST TWO WELL-
DEFINED MESOSCALE CONVECTIVE VORTICES IN THE VICINITY OF OUR
SOUTHERN BORDER REGION BUT HOW THEY WILL MANIFEST THEMSELVES WITHIN
THE NEXT FEW HOURS AS DAYTIME HEATING/INSTABILITY PEAK IS UNCLEAR.
REGION OF VERY FAVORABLE 300-400 MB DEFORMATION IS DEFINITELY
CONTRIBUTING TO AN ACTIVE CROP OVER THE WEST AND A BIT FARTHER
NORTH THAN WHAT MODELS SUGGESTED.
WILL CONTINUE TO FOCUS THE BEST POPS ACROSS THE NC/NE AND
EVENTUALLY EC ZONES AS WELL AS THE WCC/SW. SHORT- WAVE TROUGH
BRUSHING NORTHEAST NEW MEXICO THROUGH THE REMAINDER OF THE
AFTERNOON WILL CONTINUE TO BOOST STORM COVERAGE/INTENSITY THERE
WITH A FEW STRONG/SEVERE STORMS A GOOD BET. SEWD-MOVING AND
GRADUALLY EXPANDING/DEEPENING COLD POOLS WILL LIKELY TOUCH OFF NEW
CONVECTION FARTHER SOUTH...AND THE LATEST HRRR STRONG SUGGESTS A
LARGER CONVECTIVE COMPLEX TAKING SHAPE ACROSS PARTS OF EC PLAINS.
EARLIER EXPANSION OF THE FLASH FLOOD WATCH NOT LOOKING GREAT THUS
FAR...BUT WILL LET RIDE FOR EVENING CREW TO REEVALUATE.
IN WAKE OF THE SUBTLE SHORT-WAVE FEATURE THIS AFTERNOON/EARLY
EVENING... MODELS ADVERTISE A NEW BACKDOOR FRONTAL BOUNDARY TO
SLOWLY MAKE ITS WAY SOUTH AND EVENTUALLY WEST DURING THE DAY
FRIDAY. SOMEWHAT DRIER/MORE STABLE AIR MASS EXPECTED TO LIMIT
CONVECTION ACROSS MUCH OF THE NE/EC PLAINS THOUGH LOW LEVEL UPSLOPE
SHOULD PROVE BENEFICIAL FOR THE EAST SLOPES OF THE SANGRES.
OTHERWISE...UPPER HIGH CENTERED TO OUR NORTHWEST SLOWLY BUILDS OUR
DIRECTION. THOUGH NOT AS ROBUST AS TODAY...A NW TO SE STEERING
FLOW WILL CONTINUE FAVOR THE HIGH PLAINS ON FRIDAY WITH THE
COMBINATION OF DEEPER MOISTURE/VERY WEAK STEERING FLOW FAVORING
THE WC/SW ZONES FOR PERSISTENT FLASH FLOOD THREAT.
THE UPPER HIGH WILL CONTINUE TO PRESS SOUTHWARD INTO THE WEEKEND
AND ESPECIALLY EARLY NEXT WEEK WITH A MARKED TREND TOWARD A DRIER
CONDITIONS BENEATH ENHANCED WEST TO EAST FLOW REGIME. IN OTHER
WORDS THE WESTERLIES LOOK TO RETURN AND STRONGLY SO ACROSS
NORTHERN AREAS OF THE STATE DURING THE EXTENDED.
&&
.FIRE WEATHER...
A FAIRLY DYNAMIC DAY ON TAP AS A SHORTWAVE CAUGHT IN NORTHWEST FLOW
MOVES OVER THE CENTRAL AND SOUTHERN ROCKIES. STORMS HAVE FIRED UP
AHEAD OF THIS SHORTWAVE ACROSS NORTH CENTRAL AND NORTHEAST AREAS.
RESIDUAL MONSOONAL MOISTURE CAUGHT WITHIN A DEFORMATION ZONE OR
LIFTING ZONE IS FOUND ELSEWHERE. STORMS ARE GRADUALLY FIRING UP
WITHIN THIS ZONE. EXPECTING ANOTHER ACTIVE THUNDERSTORM DAY LASTING
THROUGH THE EVENING HOURS.
MODELS HAVE BEEN SHOWING SOME DRYING ACROSS THE NORTHWEST THIRD ON
FRIDAY. A BACK DOOR COLD FRONT WHICH WILL HAVE PUSHED INTO THE
EASTERN PLAINS TONIGHT FOLLOWING THE DISTURBANCE OR SHORTWAVE
PASSAGE WILL PROVIDE THE MAIN FOCUS FOR STORMS DURING THE AFTERNOON
AND EVENING FRIDAY. AS OF RIGHT NOW...THE MAIN FOCUS AREA WILL BE
FOUND ACROSS ZONE 109 EXTENDING NORTHEASTWARD TO THE SANGRE DE
CRISTOS. A MORE STABLE AIRMASS STILL LOOKS TO BE A LIMITER FOR
WETTING THUNDERSTORMS ACROSS THE FAR EASTERN PLAINS DURING THE
AFTERNOON HOURS. OVERALL...COVERAGE LOOKS TO BE SLIGHTLY LESS WITH
SLIGHTLY LESS HUMIDITY VERSUS TODAY.
MODELS ARE CONVERGING ON PLACING THE UPPER HIGH CENTER OVER FAR
SOUTHERN NM AND NORTHERN MEXICO ON SATURDAY. THE STEERING FLOW FOR THE
STORMS WOULD TURN MORE WEST TO EAST AS A RESULT. MOISTURE IS STILL
PLENTIFUL ACROSS ARIZONA SO THIS COULD ACTUALLY RESULT IN AN UPTICK
IN SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING. THIS
INCLUDES THE ENTIRE EASTERN PLAINS DUE TO STEERING FLOW
CONSIDERATIONS. WETTING RAIN AND ABUNDANT CLOUD COVER WITH AN UPTICK
IN HUMIDITY IS A PRETTY GOOD BET.
THE CENTER OF THE UPPER HIGH SHOULD REMAIN OVER NORTHERN MEXICO ON
SUNDAY. BY THIS POINT...A FAIRLY STRONG SURFACE LOW FOR THIS TIME OF
YEAR IS EXPECTED TO DEVELOP TO THE LEE OF THE CENTRAL MOUNTAINS AND
THE WESTERLY FLOW ALOFT SHOULD ALSO INCREASE SOME. MODELS VARY
SOMEWHAT ON THE STRENGTH BUT THEY STILL POINT TOWARDS A DRIER
WESTERLY FLOW. BY THIS POINT...ARIZONA IS EXPECTED TO SEE A DOWNTURN
IN MOISTURE VALUES THUS DRIER AIR SHOULD EVENTUALLY ENTRAIN ACROSS
NEW MEXICO AS A RESULT. THIS WILL NOT TOTALLY ELIMINATE THUNDERSTORM
DEVELOPMENT BUT WOULD REDUCE THE COVERAGE AND WETTING RAIN FOOTPRINT
SOME. THE GFS AND ECMWF MODELS PAINT THE MAIN FOCUS AREA FOR WETTING
RAIN ACROSS THE NORTHERN TIER OF THE STATE AND SPECIALLY ACROSS
NORTH CENTRAL AND NORTHEAST AREAS. DID BUMP UP WIND SPEEDS WHICH
LOOK MORE LIKE MID JUNE SO WILL CONTINUE TO MONITOR THIS SCENARIO.
THE LATEST GFS AND ECMWF PAINT A FURTHER REDUCTION IN SHOWER AND
THUNDERSTORM COVERAGE ON MONDAY AS DRIER AIR INFILTRATES THE STATE
FROM THE WEST. MODELS ARE VERY BULLISH ON PAINTING VERY LITTLE
CONVECTION SO WILL BE INTERESTING TO SEE WHAT TURNS OUT. EITHER
WAY...EXPECTING DRIER AND WARMER CONDITIONS EARLY NEXT WEEK. AS THE
WEEK PROGRESSES...EXPECTING SOME SORT OF MOISTURE SEEPAGE AS THE
UPPER HIGH TRIES TO BUILD NORTHWARD AND PERHAPS EASTWARD. THE SEEPAGE WOULD
MOST LIKELY COME ALONG THE CONTINENTAL DIVIDE AS WELL AS VIA A WIND
SHIFT ACROSS THE NORTHEAST. EITHER WAY...WETTING THUNDERSTORMS LOOK
TO BE MORE ON THE MINIMAL KIND THROUGH THE EARLIER HALF OF NEXT
WEEK. PERHAPS INCREASING A BIT MORE THE LATTER HALF OF NEXT WEEK IF
THE HIGH SHIFTS OVER TEXAS. SOME OF THE MODELS ARE SHOWING THIS
TREND. IT SHOULD BE POINTED OUT THAT A 3 TO 4 DAY DOWNTREND IN
WETTING THUNDERSTORMS TYPICALLY OCCURS DURING THE MONSOON MOST YEARS
SO NOTHING TOO OUT OF THE ORDINARY BUT WILL KEEP AN EYE ON
SIGNIFICANT TRENDS...WHETHER THEY BE MOISTENING OR DRYING AS WE GO
FORWARD.
&&
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 64 94 65 91 / 20 20 20 40
DULCE........................... 51 86 53 84 / 30 30 50 50
CUBA............................ 55 87 54 84 / 30 40 50 60
GALLUP.......................... 58 88 59 84 / 50 40 30 40
EL MORRO........................ 53 80 54 77 / 40 40 40 60
GRANTS.......................... 58 85 58 81 / 30 40 40 50
QUEMADO......................... 57 82 57 80 / 50 40 30 60
GLENWOOD........................ 60 85 60 84 / 60 40 30 50
CHAMA........................... 50 77 50 74 / 30 40 60 60
LOS ALAMOS...................... 60 81 59 80 / 30 40 50 50
PECOS........................... 57 75 56 75 / 50 50 60 50
CERRO/QUESTA.................... 53 79 53 78 / 30 50 50 40
RED RIVER....................... 46 68 45 68 / 50 60 70 50
ANGEL FIRE...................... 43 72 43 72 / 40 60 70 50
TAOS............................ 52 83 53 82 / 30 40 40 40
MORA............................ 53 74 53 75 / 60 60 60 50
ESPANOLA........................ 59 87 59 85 / 30 30 40 30
SANTA FE........................ 59 80 58 79 / 40 40 50 50
SANTA FE AIRPORT................ 61 84 60 83 / 40 40 40 40
ALBUQUERQUE FOOTHILLS........... 67 87 66 85 / 40 40 40 40
ALBUQUERQUE HEIGHTS............. 68 88 67 87 / 30 30 40 40
ALBUQUERQUE VALLEY.............. 67 90 66 88 / 30 30 40 30
ALBUQUERQUE WEST MESA........... 66 92 65 90 / 30 30 40 30
LOS LUNAS....................... 66 89 65 87 / 40 30 40 30
RIO RANCHO...................... 66 92 65 90 / 30 30 40 40
SOCORRO......................... 66 93 66 92 / 50 40 30 40
SANDIA PARK/CEDAR CREST......... 60 85 59 84 / 50 40 40 50
TIJERAS......................... 61 83 60 81 / 40 40 40 40
MORIARTY/ESTANCIA............... 59 82 57 81 / 40 40 40 50
CLINES CORNERS.................. 58 79 57 78 / 60 50 40 50
GRAN QUIVIRA.................... 60 83 59 81 / 40 50 30 50
CARRIZOZO....................... 64 85 63 83 / 40 40 30 50
RUIDOSO......................... 57 76 55 75 / 50 50 30 60
CAPULIN......................... 55 77 55 81 / 60 40 30 40
RATON........................... 58 82 57 85 / 60 60 30 30
SPRINGER........................ 58 83 57 85 / 60 50 30 30
LAS VEGAS....................... 56 78 56 79 / 60 50 40 50
CLAYTON......................... 64 84 61 87 / 40 10 10 20
ROY............................. 62 81 61 83 / 60 40 30 30
CONCHAS......................... 67 87 66 89 / 60 20 30 20
SANTA ROSA...................... 66 87 65 86 / 60 30 30 30
TUCUMCARI....................... 70 90 68 92 / 60 10 10 20
CLOVIS.......................... 67 88 63 88 / 40 20 10 10
PORTALES........................ 67 88 64 88 / 40 20 10 10
FORT SUMNER..................... 69 88 67 87 / 60 20 10 20
ROSWELL......................... 70 93 69 90 / 40 20 20 20
PICACHO......................... 63 86 62 85 / 40 30 30 40
ELK............................. 60 79 58 77 / 40 40 40 40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1204 PM MDT THU JUL 25 2013
.UPDATE...
SHORT-WAVE TROUGH TO BRUSH NC/NE AREAS OF THE STATE EARLY TODAY
AND ALREADY SEEING STRONG CONVECTION ROLLING SEWD FROM SOUTH-
CENTRAL COLORADO. DECIDED TO EXPAND THE FLASH FLOOD WATCH
EASTWARD TO INCLUDE AREAS THAT WERE ESPECIALLY HARD HIT ON
WEDNESDAY. DID NOT INCLUDE THE NC/NE ZONES WHERE STORM MOTIONS
WILL BE PRETTY DECENT AS COMPARED TO RECENT DAYS. POTENTIAL FOR A
FEW STRONG IF NOT SEVERE STORMS HERE...ESPECIALLY ACROSS THE
NORTHEAST PLAINS AND NORTHERN PORTIONS OF THE EAST CENTRAL PLAINS
IF THE LATEST HRRR IS CORRECT. OTHERWISE...UPPER LEVEL COL REGION
OVER THE SOUTHWEST PART OF THE FORECAST AREA TODAY WHERE THE FLASH
FLOOD THREAT ARGUABLY IS THE HIGHEST. KJ
&&
.PREV DISCUSSION...1155 AM MDT THU JUL 25 2013...
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
50
.PREV DISCUSSION...603 AM MDT THU JUL 25 2013...
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1155 AM MDT THU JUL 25 2013
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
50
&&
.PREV DISCUSSION...603 AM MDT THU JUL 25 2013...
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
603 AM MDT THU JUL 25 2013
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
&&
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES...
NMZ508-509-520-524>526-539-540.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
310 AM MDT THU JUL 25 2013
.DISCUSSION...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
&&
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.AVIATION...
06Z TAF CYCLE
PRECIPITATION HAS DIMINISHED SIGNIFICANTLY OVER NORTHERN AND
CENTRAL NEW MEXICO. SOME BATCHES OF LIGHT TO MODERATE RAIN ARE
CONTINUING OVER EASTERN PARTS OF THE STATE...AND WILL MOST LIKELY
IMPACT TAF SITES KLVS...KTCC...AND KROW THROUGH 25/1200UTC. SOME
STORMS IN SOUTHERN NEW MEXICO MAY CREEP NORTHWARD TOWARD KONM AND
NEARBY POINTS THROUGH THE MORNING...BUT OVERALL ACTIVITY WILL
CONTINUE A DOWNWARD TREND THROUGH THE OVERNIGHT. SCATTERED TO
NUMEROUS STORMS WILL REDEVELOP OVER NORTHERN AND CENTRAL NEW
MEXICO ON THURSDAY AS THE ATMOSPHERE DESTABILIZES AGAIN.
52
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 93 64 95 65 / 20 10 20 20
DULCE........................... 84 51 86 53 / 40 20 30 50
CUBA............................ 87 55 87 54 / 40 20 40 60
GALLUP.......................... 85 58 88 59 / 40 30 40 30
EL MORRO........................ 79 53 80 54 / 50 30 40 40
GRANTS.......................... 83 58 85 58 / 40 30 30 40
QUEMADO......................... 79 57 83 57 / 50 30 40 40
GLENWOOD........................ 80 60 85 60 / 40 30 30 30
CHAMA........................... 76 49 77 50 / 50 30 40 60
LOS ALAMOS...................... 80 60 82 59 / 40 30 40 50
PECOS........................... 75 57 75 56 / 60 30 50 60
CERRO/QUESTA.................... 78 53 79 54 / 50 30 50 50
RED RIVER....................... 68 46 69 45 / 60 40 50 70
ANGEL FIRE...................... 72 43 72 43 / 60 30 50 70
TAOS............................ 80 52 83 53 / 40 30 40 40
MORA............................ 74 53 74 53 / 60 30 50 60
ESPANOLA........................ 85 59 87 59 / 40 20 30 40
SANTA FE........................ 79 59 80 59 / 50 30 40 50
SANTA FE AIRPORT................ 83 61 83 60 / 50 30 40 50
ALBUQUERQUE FOOTHILLS........... 85 68 87 66 / 50 30 40 50
ALBUQUERQUE HEIGHTS............. 87 69 88 67 / 50 30 30 50
ALBUQUERQUE VALLEY.............. 89 68 90 67 / 50 30 30 50
ALBUQUERQUE WEST MESA........... 92 67 92 66 / 50 30 30 50
LOS LUNAS....................... 87 66 89 66 / 50 30 30 50
RIO RANCHO...................... 91 66 92 65 / 50 30 30 50
SOCORRO......................... 89 67 92 66 / 60 30 30 40
SANDIA PARK/CEDAR CREST......... 82 60 84 59 / 60 40 40 50
TIJERAS......................... 83 61 83 60 / 60 30 40 50
MORIARTY/ESTANCIA............... 81 59 82 58 / 60 30 40 50
CLINES CORNERS.................. 78 58 79 57 / 60 40 50 50
GRAN QUIVIRA.................... 80 61 83 59 / 60 30 50 40
CARRIZOZO....................... 84 64 85 63 / 60 30 40 30
RUIDOSO......................... 77 57 76 55 / 70 40 50 40
CAPULIN......................... 79 55 77 55 / 60 30 20 30
RATON........................... 83 58 82 57 / 60 30 30 30
SPRINGER........................ 84 58 83 57 / 60 30 20 30
LAS VEGAS....................... 79 56 79 56 / 60 30 40 50
CLAYTON......................... 86 64 83 61 / 60 40 10 10
ROY............................. 81 62 81 61 / 60 40 20 30
CONCHAS......................... 87 68 87 66 / 60 40 20 20
SANTA ROSA...................... 85 67 87 65 / 60 40 20 20
TUCUMCARI....................... 90 70 90 68 / 60 40 10 10
CLOVIS.......................... 88 67 88 63 / 60 40 20 10
PORTALES........................ 88 68 89 63 / 60 40 20 10
FORT SUMNER..................... 87 70 88 67 / 60 40 20 10
ROSWELL......................... 92 71 92 70 / 70 30 20 20
PICACHO......................... 87 64 86 63 / 70 30 30 30
ELK............................. 80 61 79 59 / 70 30 40 50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES...
NMZ508-509-520-524>526-539-540.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
737 PM EDT FRI JUL 26 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY TONIGHT AND
SATURDAY...WITH DRY CONDITIONS AND NEAR NORMAL TEMPERATURES
EXPECTED. THE NEXT SYSTEM WILL IMPACT OUR REGION WITH SEVERAL
PERIODS OF SHOWERS FROM SATURDAY NIGHT THROUGH EARLY MONDAY. THE
BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE SUNDAY AFTERNOON INTO
EARLY MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 737 PM EDT FRIDAY...CURRENT FORECAST IN EXCELLENT SHAPE AND
ONLY MINOR ADJUSTMENTS TO SKY COVER AND T/TD DATA TO MATCH 23Z
OBSERVATIONAL TRENDS NEEDED. LOW PRESSURE ALONG THE EASTERN MAINE
COAST WILL CONTINUE TO PULL AWAY INTO THE MARITIMES THIS EVENING
AS MID AND HIGH LEVEL CLOUDS SLOWLY THIN TO MAINLY CLEAR SKIES
AFTER MIDNIGHT. STILL COULD SEE A BRIEF SPRINKLE ACROSS FAR NERN
VT THROUGH SUNSET...BUT OVERALL A DRY FORECAST FOR TONIGHT. GIVEN
THE DEPARTING HIGH CLOUDS...COULD ALSO HAVE A FAIRLY ROSY SUNSET
FOR A FEW AREAS. PATCHY FOG ALSO A GOOD BET WITH T-CROSSOVER
VALUES BEING REACHED AT SEVERAL LOCALES...ESP ERN VT VALLEYS WHERE
SIMULATED WRF-ABI IMAGERY AND RAP13 VSBY PROGS SHOWING THIS AREA
QUITE FAVORED LATER TONIGHT. HAVE A GREAT EVENING. PRIOR
DISCUSSION FOLLOWS...
FCST FOCUS WL BE POPS ACRS EASTERN VT...FOLLOWED BY CLRING AND
POTENTIAL FOG DEVELOPMENT. POTENT S/W ENERGY AND ASSOCIATED CLOSED
5H/7H CIRCULATION CONTS TO MOVE INTO EASTERN NEW ENGLAND...WHILE
BACKSIDE MOISTURE LEAF IS WEAKENING OVER CENTRAL/EASTERN VT. BOTH
RAP13 AND 3KM HRRR MODELS CONT TO SHOW WEAK COMPOSITE REFLECTIVITY
RETURNS ACRS EASTERN VT THRU 03Z THIS EVENING...THEREFORE WL
MENTION CHC POPS...SIMILAR TO PREVIOUS FCST. OTHERWISE...LARGE
SCALE SUBSIDENCE BEHIND POTENT S/W ENERGY SHOULD RESULT IN
DECREASE CLOUDS...WHICH IS SUPPORTED BY LATEST SATL PIC TRENDS
ACRS CENTRAL/NORTHERN NY. THIS WINDOW OF CLRING IS SMALL...BEFORE
CLOUDS AHEAD OF OUR NEXT SYSTEM APPROACHING OUR FA. TEMPS WL BE
HIGHLY DEPEND UPON CLOUDS WITH COOLEST TEMPS ACRS THE DACKS AND
WARMEST CPV/CT RIVER VALLEY...MAINLY IN THE 40S TO M50S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 410 PM EDT FRIDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED WITH
SEVERAL ROUNDS OF SHOWERS WITH EMBEDDED STORMS
LIKELY...ESPECIALLY SUNDAY AFTN INTO EARLY MONDAY. STILL SOME
UNCERTAINTY ON TIMING OF PRECIP...WITH NAM MUCH SLOWER THAN
GFS/ECMWF. WL USE A BLEND BTWN THE 12Z GUIDANCE AND PREVIOUS
FCSTERS...WHICH SUPPORTS CHCS POPS SAT NIGHT WITH LIKELY/CAT
POPS...ESPECIALLY SUNDAY AFTN/EVENING.
WATER VAPOR SHOWS DEEP CLOSED 5H/7H CIRCULATION ACRS THE WESTERN
GREAT LAKES WITH A FULL LATITUDE TROF DEVELOPING OVER THE MS VALLEY.
THIS DEEP CYCLONIC CIRCULATION WL EJECT SEVERAL PIECES OF ENERGY
ALONG WITH RIBBONS OF ENHANCED MOISTURE ACRS OUR CWA FROM SAT NIGHT
THRU SUNDAY NIGHT. THE FIRST WAVE ARRIVES ACRS OUR WESTERN CWA
AROUND 06Z SUNDAY...BEFORE WEAKENING OVER THE CPV BY 15Z
SUNDAY...NEXT S/W ENERGY...DEEPER 850 TO 500MB RH AND SOME WEAK
INSTABILITY ARRIVES BTWN 21Z-03Z SUNDAY AFTN/EVENING...WITH MORE
SHOWERS. FEEL A SLIGHTLY SLOWER SOLUTION FOR 2ND ROUND OF RAIN WITH
EMBEDDED STORMS LOOKS REASONABLE GIVEN FRNT IS PARALLELING ULVL FLW
AND TROF/CLOSED SYSTEM IS STILL LOCATED OVER THE CENTRAL GREAT LAKES
ON SUNDAY AFTN.
IN ADDITION...POTENTIAL FOR LOCALIZED HEAVY RAINFALL
AND TRAINING OF SHOWERS WITH EMBEDDED CONVECTION WL BE
POSSIBLE...GIVEN POSITION OF 85H JET OF 30 KNOTS ALONG BOUNDARY AND
FA UNDER RRQ OF 100 KNT AT 25H. FURTHERMORE...DEEP SOUTHERLY FLW WL
HELP TO ADVECT PW VALUES BTWN 1.75 AND 2.0" ALONG AND AHEAD OF SFC
BOUNDARY ON SUNDAY...WITH INCREASED HUMIDITY VALUES LIKELY. SOUNDING
PROFILES SHOW A TALL SKINNY CAPE WITH VALUES BTWN 300 AND 600 J/KG
AND WARM CLOUD DEPTHS AROUND 12KFT...ALONG WITH VECTOR ANALYSIS
SUGGESTING TRAINING OF CONVECTION...ESPECIALLY SUNDAY AFTN/EVENING.
THINKING RAINFALL QPF WL RANGE BTWN 0.50" TO 2.0" BY MONDAY
MORNING...WITH GREATEST ACTIVE BTWN 21Z AND 03Z SUNDAY AFTN/EVENING.
WL KEEP SAT DRY ATTM...BUT GIVEN SMALL WINDOW OF CLR SKIES ON LATEST
SATL PICS...EXPECT MID/UPPER LVL CLOUDS TO ADVANCE FROM WEST TO EAST
ACRS OUR REGION.
LOCAL 2KM AND 4KM COMPOSITE REFLECTIVITY PROGS FOR SUNDAY AFTN
SUGGEST THE POTENTIAL FOR A FINE LINE OF CONVECTION WITH SOME GUSTY
WINDS POSSIBLE. SOUNDINGS INDICATE A HIGH SHEARED...BUT LOW CAPE
ENVIRONMENT...SUPPORTING LOW TOP CONVECTION WITH GUSTY WINDS
POSSIBLE.
WL MENTION CHC/LOW LIKELY POPS SAT NIGHT...WITH HIGHEST POPS WESTERN
CWA...WITH SCHC EASTERN VT. SUNDAY WL BE TRICKY WITH RAIN LIKELY IN
THE MORNING FOR THE DACKS/SLV...WITH CHC POPS VT...THEN MORE RAIN
LIKELY TO CAT AFT 21Z. I WOULD EXPECT SOME DRY PERIODS ON SUNDAY.
PROGGED 85H TEMPS SUPPORT HIGHS M70S MTNS (DACKS)TO L/M80S WARMER
VALLEYS ON SAT. CLOUDS/PRECIP WL KEEP TEMPS MAINLY IN THE 70S TO
L80S ON SUNDAY...EVEN WITH SLIGHTLY WARMER 85H TEMPS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 410 PM EDT FRIDAY...UPPER TROUGH AXIS WILL EXIST OVER SOUTHEAST
ONTARIO AND THE OHIO VALLEY AT THE START OF THE PERIOD...BUT NOT
MOVE EAST OF THE AREA UNTIL TUESDAY NIGHT. PRONOUNCED DRY SLOT AT
THE START OF MONDAY WILL KEEP ANY PRECIPITATION OVER EASTERN
VERMONT EARLY...THEN SOME DESTABILIZATION LATER IN THE DAY MAY
ENHANCE A FEW SHOWERS OVER NORTHERN NEW YORK. STEEPER LAPSE RATES
DEVELOP ON TUESDAY WITH UPPER TROUGH AXIS MOVING ACROSS THE AREA
AND STILL LOOKING FOR AFTERNOON SHOWERS ACROSS MOST OF THE NORTH
COUNTRY. WESTERLY FLOW ALOFT FOR WEDNESDAY SUGGESTS THAT WILL BE
THE DRIEST PERIOD OF THE EXTENDED BEFORE FLOW ALOFT BACKS ON
THURSDAY AHEAD OF A SHORTWAVE TROUGH. THUS GOING FORECAST OF A
CHANCE OF SHOWERS STILL LOOKS GOOD WITH SLOWLY IMPROVING
CONDITIONS ON FRIDAY. HIGH TEMPERATURES THROUGH THE PERIOD WILL BE
AT OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR FOR MOST OF THE TAFS THROUGH THE PERIOD
EXCEPT FOR IFR TO VLIFR IN MIST/FOG AT SLK AND MPV. VIS/WV
SATELLITE SHOW DECK OF MID/HIGH CLOUDS CLEARING FROM SOUTHWEST TO
NORTHEAST AS UPPER-LEVEL DRY SLOT OVERTAKES THE REGION. SIMILAR
CONDITIONS TONIGHT AS LAST NIGHT AT SLK SO SEE NO REASON WHY SLK
WON`T RECEIVE FOG TONIGHT...AND A BETTER CHANCE AT FOG/MIST AT MPV
BASED ON CROSSOVER TEMPS IN THE MID 50S...CLEARING SKIES AND LIGHT
SFC WINDS. THERE MAY BE A PERIOD OF BRIEF MVFR MIST AT BTV TOWARDS
MORNING. FOG/MIST LIFTS 11-13Z TOMORROW PRODUCING VFR CONDITIONS.
INCREASING CLOUDS WITH VCSH INTRODUCED AT MSS LATE IN THE PERIOD
WITH SLOW APPROACH OF GREAT LAKES SFC CYCLONE & FRONT.
LIGHT/VARIABLE WINDS /EXCEPT NORTHEAST AROUND 5-6KTS MSS/
OVERNIGHT GRADUALLY BECOME SOUTHWEST/SOUTH 5-8KTS SATURDAY.
OUTLOOK 00Z SUNDAY THROUGH TUESDAY...
00Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR WITH PERIODS OF
MVFR/IFR LIKELY IN SHOWERS AND POSSIBLE TSRA WITH COLD FRONT
PASSAGE.
12Z MONDAY THROUGH TUESDAY...MAINLY VFR WITH THE CHANCE FOR MVFR
RAIN SHOWERS EACH AFTERNOON AS UPPER LEVEL LOW PRESSURE SHIFTS
EAST THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...JMG/TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
723 PM EDT FRI JUL 26 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY TONIGHT AND
SATURDAY...WITH DRY CONDITIONS AND NEAR NORMAL TEMPERATURES
EXPECTED. THE NEXT SYSTEM WILL IMPACT OUR REGION WITH SEVERAL
PERIODS OF SHOWERS FROM SATURDAY NIGHT THROUGH EARLY MONDAY. THE
BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE SUNDAY AFTERNOON INTO
EARLY MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 410 PM EDT FRIDAY...FCST FOCUS WL BE POPS ACRS EASTERN VT...FOLLOWED
BY CLRING AND POTENTIAL FOG DEVELOPMENT. POTENT S/W ENERGY AND
ASSOCIATED CLOSED 5H/7H CIRCULATION CONTS TO MOVE INTO EASTERN NEW
ENGLAND...WHILE BACKSIDE MOISTURE LEAF IS WEAKENING OVER
CENTRAL/EASTERN VT. BOTH RAP13 AND 3KM HRRR MODELS CONT TO SHOW
WEAK COMPOSITE REFLECTIVITY RETURNS ACRS EASTERN VT THRU 03Z THIS
EVENING...THEREFORE WL MENTION CHC POPS...SIMILAR TO PREVIOUS
FCST. OTHERWISE...LARGE SCALE SUBSIDENCE BEHIND POTENT S/W ENERGY
SHOULD RESULT IN DECREASE CLOUDS...WHICH IS SUPPORTED BY LATEST
SATL PIC TRENDS ACRS CENTRAL/NORTHERN NY. THIS WINDOW OF CLRING IS
SMALL...BEFORE CLOUDS AHEAD OF OUR NEXT SYSTEM APPROACHING OUR FA.
TEMPS WL BE HIGHLY DEPEND UPON CLOUDS WITH COOLEST TEMPS ACRS THE
DACKS AND WARMEST CPV/CT RIVER VALLEY...MAINLY IN THE 40S TO M50S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 410 PM EDT FRIDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED WITH
SEVERAL ROUNDS OF SHOWERS WITH EMBEDDED STORMS
LIKELY...ESPECIALLY SUNDAY AFTN INTO EARLY MONDAY. STILL SOME
UNCERTAINTY ON TIMING OF PRECIP...WITH NAM MUCH SLOWER THAN
GFS/ECMWF. WL USE A BLEND BTWN THE 12Z GUIDANCE AND PREVIOUS
FCSTERS...WHICH SUPPORTS CHCS POPS SAT NIGHT WITH LIKELY/CAT
POPS...ESPECIALLY SUNDAY AFTN/EVENING.
WATER VAPOR SHOWS DEEP CLOSED 5H/7H CIRCULATION ACRS THE WESTERN
GREAT LAKES WITH A FULL LATITUDE TROF DEVELOPING OVER THE MS VALLEY.
THIS DEEP CYCLONIC CIRCULATION WL EJECT SEVERAL PIECES OF ENERGY
ALONG WITH RIBBONS OF ENHANCED MOISTURE ACRS OUR CWA FROM SAT NIGHT
THRU SUNDAY NIGHT. THE FIRST WAVE ARRIVES ACRS OUR WESTERN CWA
AROUND 06Z SUNDAY...BEFORE WEAKENING OVER THE CPV BY 15Z
SUNDAY...NEXT S/W ENERGY...DEEPER 850 TO 500MB RH AND SOME WEAK
INSTABILITY ARRIVES BTWN 21Z-03Z SUNDAY AFTN/EVENING...WITH MORE
SHOWERS. FEEL A SLIGHTLY SLOWER SOLUTION FOR 2ND ROUND OF RAIN WITH
EMBEDDED STORMS LOOKS REASONABLE GIVEN FRNT IS PARALLELING ULVL FLW
AND TROF/CLOSED SYSTEM IS STILL LOCATED OVER THE CENTRAL GREAT LAKES
ON SUNDAY AFTN.
IN ADDITION...POTENTIAL FOR LOCALIZED HEAVY RAINFALL
AND TRAINING OF SHOWERS WITH EMBEDDED CONVECTION WL BE
POSSIBLE...GIVEN POSITION OF 85H JET OF 30 KNOTS ALONG BOUNDARY AND
FA UNDER RRQ OF 100 KNT AT 25H. FURTHERMORE...DEEP SOUTHERLY FLW WL
HELP TO ADVECT PW VALUES BTWN 1.75 AND 2.0" ALONG AND AHEAD OF SFC
BOUNDARY ON SUNDAY...WITH INCREASED HUMIDITY VALUES LIKELY. SOUNDING
PROFILES SHOW A TALL SKINNY CAPE WITH VALUES BTWN 300 AND 600 J/KG
AND WARM CLOUD DEPTHS AROUND 12KFT...ALONG WITH VECTOR ANALYSIS
SUGGESTING TRAINING OF CONVECTION...ESPECIALLY SUNDAY AFTN/EVENING.
THINKING RAINFALL QPF WL RANGE BTWN 0.50" TO 2.0" BY MONDAY
MORNING...WITH GREATEST ACTIVE BTWN 21Z AND 03Z SUNDAY AFTN/EVENING.
WL KEEP SAT DRY ATTM...BUT GIVEN SMALL WINDOW OF CLR SKIES ON LATEST
SATL PICS...EXPECT MID/UPPER LVL CLOUDS TO ADVANCE FROM WEST TO EAST
ACRS OUR REGION.
LOCAL 2KM AND 4KM COMPOSITE REFLECTIVITY PROGS FOR SUNDAY AFTN
SUGGEST THE POTENTIAL FOR A FINE LINE OF CONVECTION WITH SOME GUSTY
WINDS POSSIBLE. SOUNDINGS INDICATE A HIGH SHEARED...BUT LOW CAPE
ENVIRONMENT...SUPPORTING LOW TOP CONVECTION WITH GUSTY WINDS
POSSIBLE.
WL MENTION CHC/LOW LIKELY POPS SAT NIGHT...WITH HIGHEST POPS WESTERN
CWA...WITH SCHC EASTERN VT. SUNDAY WL BE TRICKY WITH RAIN LIKELY IN
THE MORNING FOR THE DACKS/SLV...WITH CHC POPS VT...THEN MORE RAIN
LIKELY TO CAT AFT 21Z. I WOULD EXPECT SOME DRY PERIODS ON SUNDAY.
PROGGED 85H TEMPS SUPPORT HIGHS M70S MTNS (DACKS)TO L/M80S WARMER
VALLEYS ON SAT. CLOUDS/PRECIP WL KEEP TEMPS MAINLY IN THE 70S TO
L80S ON SUNDAY...EVEN WITH SLIGHTLY WARMER 85H TEMPS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 410 PM EDT FRIDAY...UPPER TROUGH AXIS WILL EXIST OVER SOUTHEAST
ONTARIO AND THE OHIO VALLEY AT THE START OF THE PERIOD...BUT NOT
MOVE EAST OF THE AREA UNTIL TUESDAY NIGHT. PRONOUNCED DRY SLOT AT
THE START OF MONDAY WILL KEEP ANY PRECIPITATION OVER EASTERN
VERMONT EARLY...THEN SOME DESTABILIZATION LATER IN THE DAY MAY
ENHANCE A FEW SHOWERS OVER NORTHERN NEW YORK. STEEPER LAPSE RATES
DEVELOP ON TUESDAY WITH UPPER TROUGH AXIS MOVING ACROSS THE AREA
AND STILL LOOKING FOR AFTERNOON SHOWERS ACROSS MOST OF THE NORTH
COUNTRY. WESTERLY FLOW ALOFT FOR WEDNESDAY SUGGESTS THAT WILL BE
THE DRIEST PERIOD OF THE EXTENDED BEFORE FLOW ALOFT BACKS ON
THURSDAY AHEAD OF A SHORTWAVE TROUGH. THUS GOING FORECAST OF A
CHANCE OF SHOWERS STILL LOOKS GOOD WITH SLOWLY IMPROVING
CONDITIONS ON FRIDAY. HIGH TEMPERATURES THROUGH THE PERIOD WILL BE
AT OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR FOR MOST OF THE TAFS THROUGH THE PERIOD
EXCEPT FOR IFR TO VLIFR IN MIST/FOG AT SLK AND MPV. VIS/WV
SATELLITE SHOW DECK OF MID/HIGH CLOUDS CLEARING FROM SOUTHWEST TO
NORTHEAST AS UPPER-LEVEL DRY SLOT OVERTAKES THE REGION. SIMILAR
CONDITIONS TONIGHT AS LAST NIGHT AT SLK SO SEE NO REASON WHY SLK
WON`T RECEIVE FOG TONIGHT...AND A BETTER CHANCE AT FOG/MIST AT MPV
BASED ON CROSSOVER TEMPS IN THE MID 50S...CLEARING SKIES AND LIGHT
SFC WINDS. THERE MAY BE A PERIOD OF BRIEF MVFR MIST AT BTV TOWARDS
MORNING. FOG/MIST LIFTS 11-13Z TOMORROW PRODUCING VFR CONDITIONS.
INCREASING CLOUDS WITH VCSH INTRODUCED AT MSS LATE IN THE PERIOD
WITH SLOW APPROACH OF GREAT LAKES SFC CYCLONE & FRONT.
LIGHT/VARIABLE WINDS /EXCEPT NORTHEAST AROUND 5-6KTS MSS/
OVERNIGHT GRADUALLY BECOME SOUTHWEST/SOUTH 5-8KTS SATURDAY.
OUTLOOK 00Z SUNDAY THROUGH TUESDAY...
00Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR WITH PERIODS OF
MVFR/IFR LIKELY IN SHOWERS AND POSSIBLE TSRA WITH COLD FRONT
PASSAGE.
12Z MONDAY THROUGH TUESDAY...MAINLY VFR WITH THE CHANCE FOR MVFR
RAIN SHOWERS EACH AFTERNOON AS UPPER LEVEL LOW PRESSURE SHIFTS
EAST THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
408 PM EDT THU JUL 25 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ACROSS THE NORTH COUNTRY THROUGH
FRIDAY...AS LOW PRESSURE MOVES TOWARD CAPE COD. THIS WILL INCREASE
CLOUDS ACROSS PARTS OF OUR REGION...WITH A CHANCE OF SHOWERS
POSSIBLE FOR EASTERN VERMONT THROUGH FRIDAY. A STRONGER SYSTEM AND
ASSOCIATED FRONT WILL PRODUCE A PERIOD OF SHOWERS WITH EMBEDDED
STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL
THROUGH FRIDAY...BEFORE RETURNING CLOSE TO NORMAL OVER THE
WEEKEND...WITH SOME INCREASE IN HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
AS OF 410 PM EDT THURSDAY...WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS
THE EASTERN CONUS WHILE POTENT S/W ENERGY AND DEEP TROPICAL
MOISTURE IS LOCATED OFF THE MID ATLANTIC COAST. THIS ENERGY WL
HELP IN THE DEVELOPMENT OF SFC LOW PRES TONIGHT...WHICH WL TRACK
TWD CAPE COD BY FRIDAY. LATEST 12Z GUIDANCE SHOWS A SLIGHT
WESTWARD TRACK AND PLACEMENT OF QPF...BUT STILL MAINLY EAST OF OUR
CWA. LATEST HRRR REFLECTIVITY AND QPF PROGS SHOW LIGHT RAIN
SHOWERS IMPACTING ORANGE AND WINDSOR COUNTIES AFT 04Z TONIGHT. WL
MENTION CHC POPS ACRS THIS REGION. NAM/GFS SHOW A CLOSED 7H
CIRCULATION OVER SNE...WITH SFC LOW PRES OVER CAPE COD AT 18Z
FRIDAY...AS BEST 850 TO 500MB RH AND UVVS FIELDS ARE JUST EAST OF
OUR CWA. BOTH MODELS ALONG WITH THE ECMWF SHOW A SHARP WEST TO
EAST GRADIENT IN RH AND QPF FIELDS...THRU FRIDAY. WL CONT TO
MENTION SCHC TO LOW CHC POPS ACRS EASTERN VT. THINKING MOST PRECIP
WL EVAPORATE BEFORE REACHING THE GROUND...PER DEPTH OF DRY LAYER
ON SOUNDINGS. TEMPS WL BE TRICKY TONIGHT...BASED ON
CLOUDS...THINKING U30S SLK TO M50S VSF.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 410 PM EDT THURSDAY...PROGRESSIVE FLW ALOFT WL QUICKLY LIFT S/W
ENERGY AND DEEPER MOISTURE NORTHEAST ALONG THE EASTERN SEABOARD
ON FRIDAY. ONCE AGAIN ANTICIPATE A SHARP WEST TO EAST GRADIENT IN
RH FIELDS...WITH MAYBE A BRIEF SHOWER ACRS EXTREME EASTERN VT. WL
CONT TO MENTION SCHC POPS. PROGGED 85H TEMPS WARM ANOTHER 2 TO 3C
FROM THURS...TO SUPPORT NEAR NORMAL HIGHS IN THE 70S MTNS TO L/M
80S VALLEYS. WARMEST TEMPS WL BE ACRS THE SLV...WHERE SKIES WL BE
SUNNY.
FRIDAY NIGHT THRU SATURDAY NIGHT...DEEP CLOSED AND NEARLY VERTICAL
STACKED SYSTEM ACRS THE CENTRAL GREAT LAKES WL SLOWLY APPROACH THE
NE CONUS. THE MID/UPPER LVL FLW AHEAD OF THIS SYSTEM WL BECM
SOUTHERLY WITH SEVERAL EMBEDDED S/W`S...ESPECIALLY SAT AFTN/EVENING.
IN ADDITION...LATEST 12Z GFS SHOWS SEVERAL RIBBONS OF ENHANCED 850
TO 500MB RH ADVECTING FROM SOUTH TO NORTH ACRS OUR FA...IN THE
SOUTHERLY FLW ALOFT. HOWEVER...BEST LLVL SFC CONVERGENCE ASSOCIATED
WITH FRNT AND LOW PRES...ALONG WITH STRONGEST JET WINDS WL STAY WEST
OF OUR CWA THRU 12Z SUNDAY. INSTABILITY LOOKS LIMITED ON SAT ACRS
OUR CWA...AS NAM/GFS SHOW BEST PARAMETERS SOUTH OF OUR
FA...ASSOCIATED WITH HIGHER BL DWPTS. WL MENTION CHC POPS AFT 18Z
SATURDAY...ASSOCIATED WITH LOW/MID LVL WAA AND MOISTURE ADVECTION
ACRS OUR FA. QPF WL BE LIGHT WITH MAINLY SPRINKLES/VIRGA OCCURRING
INITIALLY. PROGGED 85H TEMPS BTWN 13 AND 15C...SUPPORT HIGHS BACK
INTO THE U70S MTNS TO M80S WARMER VALLEYS. IN ADDITION...HUMIDITY
LVLS WL CONT TO INCREASE...ESPECIALLY BY SAT NIGHT...ASSOCIATED WITH
SOUTHERLY FLW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 410 PM EDT THURSDAY...UPPER TROUGH OVER THE EASTERN GREAT
LAKES WILL BE SLOW TO MOVE EAST THROUGH THE FIRST HALF OF THE
EXTENDED PERIOD...SUNDAY THROUGH TUESDAY. AS A RESULT...DYNAMIC
SUPPORT WILL PLAY A FACTOR IN INCREASING PRECIPITATION CHANCES ON
SUNDAY WITH LIKELY TO CATEGORICAL PRECIPITATION CHANCES EXPECTED.
AFTER SUNDAY...THE AREA GETS IN THE DRY SLOT BEHIND THE COLD
FRONT...BUT STEEPENING LAPSE RATES DUE TO COLD AIR ADVECTION ALOFT
SUGGESTS THE POTENTIAL FOR DIURNALLY DRIVEN SHOWERS ON MONDAY AND
ESPECIALLY ON TUESDAY. WILL THEREFORE GO AHEAD AND ADD A CHANCE OF
SHOWERS TO MONDAY AND TUESDAY. WITH CLOUDS AND SHOWERS LINGERING
AROUND...LOOKING AT TEMPERATURES ABOUT 2 TO 4 DEGREES BELOW
NORMAL. WESTERLY FLOW DEVELOPS WEDNESDAY AND THURSDAY...SO DRIER
WEATHER IS EXPECTED ALONG WITH TEMPERATURES RIGHT AROUND SEASONAL
NORMALS.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR EXPECTED THROUGH MUCH OF THE PERIOD. THE
ONLY EXCEPTIONS TO THIS WILL BE AT KMPV WHERE MVFR VISIBILITIES
ARE POSSIBLE BETWEEN 08Z AND 12Z AND AT KSLK WHERE VLIFR ARE
EXPECTED DUE TO LOW CLOUDS AND FOG DURING THIS SAME TIME PERIOD.
EXPECTING ONLY HIGH CLOUDS TO MOVE ACROSS THE AREA FROM THE SOUTH
WITH ANY RAIN REMAINING EAST OF THE AREA. WINDS WILL HAVE A
NORTHERLY COMPONENT TO THEM THROUGH MUCH OF THE PERIOD...BUT
SPEEDS WILL GENERALLY BE 10 KNOTS OR LESS.
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
18Z FRIDAY THROUGH 12Z SUNDAY...PRIMARILY VFR UNDER A RIDGE OF HIGH
PRESSURE.
12Z SUNDAY THROUGH TUESDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR LIKELY
IN SHOWERS AND POSSIBLE TSRA AS A COLD FRONT TRACKS THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
205 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS AFTERNOON...
WHILE WEAK HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH. THIS
HIGH PRESSURE WILL HOLD OVER THE AREA THROUGH FRIDAY NIGHT BEFORE
SHIFTING OFFSHORE ON SATURDAY. ANOTHER COLD FRONT WILL APPROACH FROM
THE NORTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM THURSDAY...
LATEST SURFACE ANALYSIS SHOWS A FEW NOTABLE BOUNDARIES AND FEATURES
ACROSS THE REGION... INCLUDING THE LEADING TROUGH/WIND SHIFT WHICH
HAS PUSHED WELL SOUTH INTO SRN GA... THE SURFACE LOW JUST OFF ILM
AND ITS TRAILING TROUGH ACROSS SRN SC WRAPPING BACK UP INTO SW NC...
AND THE PRIMARY FRONT STRETCHING NE-SW OVER NC... WHICH SEPARATES
DEWPOINTS IN THE UPPER 60S/LOWER 70S TO ITS SOUTH AND VALUES IN THE
UPPER 50S/LOWER 60S TO ITS NORTH. THIS LAST BOUNDARY HAS MOVED
LITTLE IN RECENT HOURS BUT AS THE OFFSHORE LOW CONTINUES TO DEEPEN
AND DRIFT TO THE NNE... THE ENHANCED NORTHERLY/NNERLY FLOW INTO NC
SHOULD STEADILY DRAW THE DRIER AIR TO THE NORTH FURTHER SOUTHWARD
INTO CENTRAL NC DURING THE DAY... PUSHING THE EFFECTIVE FRONTAL ZONE
SOUTHWARD. SATELLITE IMAGERY SHOWS THE MID LEVEL CLOUDINESS
ALONG/AHEAD OF THE 500 MB TROUGH AXIS OVER THE COASTAL PLAIN
SHIFTING EASTWARD... HOWEVER ABUNDANT LEFTOVER LOW LEVEL MOISTURE
AND INFLUX OF MARINE AIR IS CONTRIBUTING TO WIDESPREAD STRATOCU
DEVELOPMENT OVER THE AREA... MOVING TOWARD THE SW (A CONTRAST TO THE
EASTWARD-MOVING MID CLOUDS). THE RAP MODEL SHOWS THIS STRATOCU
SLOWLY LIFTING BUT PERSISTING WELL INTO THE AFTERNOON... AND RECENT
PILOT REPORTS SHOW THESE CLOUDS AROUND 1000-1500 FT DEEP... SO IT
WILL TAKE AWHILE FOR THESE TO BREAK UP AND MIX OUT. EXPECT MAINLY
MOSTLY CLOUDY SKIES IN THE EAST/SOUTH WITH ANY CLEAR AREAS IN THE NW
FILLING IN QUICKLY TO AT LEAST PARTLY CLOUDY. WE SHOULD SEE SOME
IMPROVEMENT LATE IN THE DAY FROM NORTH TO SOUTH AS SOME DRIER AIR TO
THE NORTH (NOTED ON 12Z IAD SOUNDING AT 925 MB) SLOWLY FILTERS IN.
WITH QUITE A BIT OF CINH AND LITTLE CAPE ANTICIPATED AS THE STRATOCU
REDUCES INSOLATION... THUNDER CHANCES APPEAR SMALL... ALTHOUGH
PATCHY SHOWERS REMAIN POSSIBLE ACROSS THE EAST AND FAR SOUTH WHERE
SURFACE DEWPOINTS HAVE YET TO DROP APPRECIABLY. WILL NUDGE POPS
DOWNWARD JUST A BIT OVERALL. TEMPS ARE RUNNING SEVERAL DEGREES BELOW
YESTERDAY`S NUMBERS... AND THIS PACE ALONG WITH NEAR TERM MODEL
GUIDANCE INDICATES HIGHS OF 80-86... A DOWNWARD BUMP IN THE
NORTHEAST WHERE CLOUD COVER WILL BE GREATEST AND WHERE THE BETTER
CHANCE OF SHOWERS WILL RESIDE. -GIH
TONIGHT...ADVECTION OF DRIER MORE STABLE AIR SHOULD LIMIT/DISSIPATE
ANY LEFTOVER AFTERNOON CONVECTION BY EARLY EVENING. SLIGHTLY DRIER
AIR WILL ALLOW TEMPS TO FALL INTO THE MID 60S ACROSS THE NORTH
OVERNIGHT AND UPPER 60S TO NEAR 70 IN THE SOUTH. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRIDAY...WEAK HIGH PRESSURE WILL NOSE SWD INTO THE REGION.
SUBSIDENCE BEHIND THE EXITING S/W SHOULD INITIALLY LIMIT CLOUD
PRODUCTION THOUGH AS AIR MASS HEATS UP...EXPECT SCATTERED CU TO
DEVELOP BY LATE MORNING-EARLY AFTERNOON. CONTINUED LOW LEVEL NE FLOW
WILL GIVE MANY PLACES A WELCOMED BREAK FROM 90+ DEGREES HEAT.
AFTERNOON TEMPS IN THE MID-UPPER 80S.
ANOTHER MID LEVEL TROUGH WILL APPROACH FROM THE WEST FRIDAY NIGHT.
UPPER LEVEL MOISTURE ADVECTION AHEAD OF THIS SYSTEM MAY RESULT IN A
DECK OF HIGH CLOUDS ENCROACHING ON OUR WESTERN COUNTIES OVERNIGHT.
THIS VEIL OF CLOUDS WILL HOLD TEMPS UP A BIT...RESULTING IN THE
COOLER MIN TEMPS OVER THE COASTAL PLAIN AND NE PIEDMONT. MIN TEMPS
MID-UPPER 60S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 205 PM THURSDAY...
A SHORT WAVE TROUGH CURRENTLY OVER THE CENTRAL PLAINS IS PROGGED TO
MOVE SE AND BOTTOM OUT IN THE BASE OF THE LONG WAVE TROUGH OVER THE
SOUTHERN APPALACHIANS EARLY SATURDAY...AND THEN SHEAR OUT ACROSS THE
MID ATLANTIC AND CAROLINAS BY LATE IN THE DAY. THE ASSOC SFC FRONT
WILL BE DELAYED BEHIND THIS FIRST SHORT WAVE...REACHING THE
CAROLINAS BY EARLY SUNDAY AS THE PARENT MID/UPR TROUGH GRADUALLY
DRIFTS ESE ACROSS THE GREAT LAKES. BOTH GFS AND ECMWF STILL SHOW THE
BEST MOISTURE INCREASE ACROSS THE WESTERN HALF OF THE STATE ON
SATURDAY...THUS FOR NOW WILL CONTINUE THE CURRENT POP ARRANGEMENT
SHOWING BEST CHANCE FOR SHOWER/TSTMS ACROSS THE WESTERN HALF OF OUR
CWA ON SATURDAY...WITH LITTLE IF ANY ACTIVITY EAST OF US1. AS THE
FRONT AND MOISTURE SHIFTS EAST SATURDAY NIGHT AND SUNDAY...WILL
EXPAND CHANCE POPS ACROSS THE ENTIRE CWA ON SUNDAY. IN TERMS OF
STORM INTENSITY...GIVE MODEST INSTABILITY AND WEAK DEEP LAYER
SHEAR...TSTMS ON SATURDAY SHOULD BE LIMITED IN INTENSITY. HOWEVER ON
SUNDAY...NOTED IN GUIDANCE A BRIEF INCREASE IN SHEAR DURING THE DAY
...SO WOULDN`T RULE OUT AN ISOLATED STRONG TSTM DURING THE DAY
SUNDAY. FINALLY...NOTED THAT PRECIP AMOUNTS IN BOTH MODELS AREN`T
PARTICULARLY HEAVY...GENERALLY LESS THAN 1/2 INCH FOR MOST
LOCATIONS...CERTAINLY NOT A WASHOUT FOR THE WEEKEND.
FOR THE REST OF THE LONG TERM...MONDAY THROUGH THURSDAY...LOOK FOR
REDUCED RAIN CHANCES ON MONDAY INTO TUESDAY AS DRYING TAKES PLACE
BEHIND THE AFOREMENTIONED FRONT AFTER IT MOVES TO OUR EAST EARLY
MONDAY. THEN THE NEXT MID LEVEL TROUGH IS PROGGED TO SET UP ACROSS
OUR AREA DURING THE MIDDLE OF THE WEEK...RESULTING IN AT LEAST
CLIMO-POPS FOR MAINLY DIURNAL SHOWERS AND TSTMS DURING THIS TIME.
REGARDING TEMPS DURING THE LONG TERM... THICKNESSES ARE PROGGED BY
THE GFS AND ECWMF TO REMAIN STEADY AND NEAR CLIMO THROUGH THE LONG
TERM PERIOD... SO LOOK FOR NEAR-NORMAL TEMPS THROUGH THE PERIOD...
HIGHS GENERALLY CLOSE TO 90 AND LOWS IN THE UPPER 60S TO NEAR 70.
THE ONLY DEVIATION FROM THIS MAY BE MONDAY NIGHT INTO TUESDAY...AS
TEMPS MAY BE A FEW DEGREES LOWER IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM THURSDAY...
VERY SLOW IMPROVEMENT FROM MVFR TO VFR BY SUNSET. AS A COLD FRONT
HAS SETTLED JUST SOUTH OF THE AREA... INCOMING COOLER AIR FROM THE
NORTH AND LOW LEVEL MOISTURE HAVE LED TO QUICK CLOUD DEVELOPMENT
THIS MORNING WITH MVFR CIGS OVER ALL OF CENTRAL NC. THIS FAIRLY
THICK DECK OF CLOUDS WILL BE SLOW TO LIFT AS COOL STABLE LOW LEVEL
AIR CONTINUES TO ADVECT INTO CENTRAL NC FROM THE NNE... SO EXPECT
MVFR CONDITIONS TO HOLD UNTIL 22Z-00Z... WHEN CIGS ARE EXPECTED TO
CLIMB JUST ABOVE 3 KFT. A FEW SHOWERS MAY AFFECT RDU/RWI/FAY BUT ARE
UNLIKELY TO REACH ENOUGH COVERAGE TO BE A PREVAILING CONDITION. VFR
CONDITIONS ARE EXPECTED TO THEN DOMINATE FROM 00Z THROUGH THE END OF
THE TAF PERIOD WITH CIGS JUST ABOVE 3 KFT. WINDS FROM THE NORTHEAST
AT 8-12 KTS MAY PERIODICALLY GUST TO 14-18 KTS UNTIL 00Z THIS
EVENING... THEN WILL BECOME LIGHT/VARIABLE UNDER 6 KTS THROUGH 18Z
FRIDAY.
LOOKING BEYOND 18Z FRIDAY... VFR CONDITIONS WILL HOLD HEADING INTO
THE WEEKEND... ALTHOUGH IFR CIGS ARE POSSIBLE AT INT/GSO LATE FRIDAY
NIGHT INTO SATURDAY MORNING... AND SCATTERED SHOWERS/STORMS
GENERATING MVFR CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON THROUGH
SUNDAY EVENING... AHEAD OF AN APPROACHING FRONT. WITH WEAK HIGH
PRESSURE BUILDING IN BEHIND THE FRONT... DRY WEATHER AND VFR
CONDITIONS ARE EXPECTED LATE SUNDAY NIGHT THROUGH TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...NP
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
133 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS AFTERNOON...
WHILE WEAK HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH. THIS
HIGH PRESSURE WILL HOLD OVER THE AREA THROUGH FRIDAY NIGHT BEFORE
SHIFTING OFFSHORE ON SATURDAY. ANOTHER COLD FRONT WILL APPROACH FROM
THE NORTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM THURSDAY...
LATEST SURFACE ANALYSIS SHOWS A FEW NOTABLE BOUNDARIES AND FEATURES
ACROSS THE REGION... INCLUDING THE LEADING TROUGH/WIND SHIFT WHICH
HAS PUSHED WELL SOUTH INTO SRN GA... THE SURFACE LOW JUST OFF ILM
AND ITS TRAILING TROUGH ACROSS SRN SC WRAPPING BACK UP INTO SW NC...
AND THE PRIMARY FRONT STRETCHING NE-SW OVER NC... WHICH SEPARATES
DEWPOINTS IN THE UPPER 60S/LOWER 70S TO ITS SOUTH AND VALUES IN THE
UPPER 50S/LOWER 60S TO ITS NORTH. THIS LAST BOUNDARY HAS MOVED
LITTLE IN RECENT HOURS BUT AS THE OFFSHORE LOW CONTINUES TO DEEPEN
AND DRIFT TO THE NNE... THE ENHANCED NORTHERLY/NNERLY FLOW INTO NC
SHOULD STEADILY DRAW THE DRIER AIR TO THE NORTH FURTHER SOUTHWARD
INTO CENTRAL NC DURING THE DAY... PUSHING THE EFFECTIVE FRONTAL ZONE
SOUTHWARD. SATELLITE IMAGERY SHOWS THE MID LEVEL CLOUDINESS
ALONG/AHEAD OF THE 500 MB TROUGH AXIS OVER THE COASTAL PLAIN
SHIFTING EASTWARD... HOWEVER ABUNDANT LEFTOVER LOW LEVEL MOISTURE
AND INFLUX OF MARINE AIR IS CONTRIBUTING TO WIDESPREAD STRATOCU
DEVELOPMENT OVER THE AREA... MOVING TOWARD THE SW (A CONTRAST TO THE
EASTWARD-MOVING MID CLOUDS). THE RAP MODEL SHOWS THIS STRATOCU
SLOWLY LIFTING BUT PERSISTING WELL INTO THE AFTERNOON... AND RECENT
PILOT REPORTS SHOW THESE CLOUDS AROUND 1000-1500 FT DEEP... SO IT
WILL TAKE AWHILE FOR THESE TO BREAK UP AND MIX OUT. EXPECT MAINLY
MOSTLY CLOUDY SKIES IN THE EAST/SOUTH WITH ANY CLEAR AREAS IN THE NW
FILLING IN QUICKLY TO AT LEAST PARTLY CLOUDY. WE SHOULD SEE SOME
IMPROVEMENT LATE IN THE DAY FROM NORTH TO SOUTH AS SOME DRIER AIR TO
THE NORTH (NOTED ON 12Z IAD SOUNDING AT 925 MB) SLOWLY FILTERS IN.
WITH QUITE A BIT OF CINH AND LITTLE CAPE ANTICIPATED AS THE STRATOCU
REDUCES INSOLATION... THUNDER CHANCES APPEAR SMALL... ALTHOUGH
PATCHY SHOWERS REMAIN POSSIBLE ACROSS THE EAST AND FAR SOUTH WHERE
SURFACE DEWPOINTS HAVE YET TO DROP APPRECIABLY. WILL NUDGE POPS
DOWNWARD JUST A BIT OVERALL. TEMPS ARE RUNNING SEVERAL DEGREES BELOW
YESTERDAY`S NUMBERS... AND THIS PACE ALONG WITH NEAR TERM MODEL
GUIDANCE INDICATES HIGHS OF 80-86... A DOWNWARD BUMP IN THE
NORTHEAST WHERE CLOUD COVER WILL BE GREATEST AND WHERE THE BETTER
CHANCE OF SHOWERS WILL RESIDE. -GIH
TONIGHT...ADVECTION OF DRIER MORE STABLE AIR SHOULD LIMIT/DISSIPATE
ANY LEFTOVER AFTERNOON CONVECTION BY EARLY EVENING. SLIGHTLY DRIER
AIR WILL ALLOW TEMPS TO FALL INTO THE MID 60S ACROSS THE NORTH
OVERNIGHT AND UPPER 60S TO NEAR 70 IN THE SOUTH. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRIDAY...WEAK HIGH PRESSURE WILL NOSE SWD INTO THE REGION.
SUBSIDENCE BEHIND THE EXITING S/W SHOULD INITIALLY LIMIT CLOUD
PRODUCTION THOUGH AS AIR MASS HEATS UP...EXPECT SCATTERED CU TO
DEVELOP BY LATE MORNING-EARLY AFTERNOON. CONTINUED LOW LEVEL NE FLOW
WILL GIVE MANY PLACES A WELCOMED BREAK FROM 90+ DEGREES HEAT.
AFTERNOON TEMPS IN THE MID-UPPER 80S.
ANOTHER MID LEVEL TROUGH WILL APPROACH FROM THE WEST FRIDAY NIGHT.
UPPER LEVEL MOISTURE ADVECTION AHEAD OF THIS SYSTEM MAY RESULT IN A
DECK OF HIGH CLOUDS ENCROACHING ON OUR WESTERN COUNTIES OVERNIGHT.
THIS VEIL OF CLOUDS WILL HOLD TEMPS UP A BIT...RESULTING IN THE
COOLER MIN TEMPS OVER THE COASTAL PLAIN AND NE PIEDMONT. MIN TEMPS
MID-UPPER 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 320 AM THURSDAY...
SATURDAY AND SATURDAY NIGHT...A WEAKENING MID-LEVEL SHORTWAVE IS
FORECAST TO MOVE INTO CENTRAL NORTH CAROLINA SATURDAY...WITH THE
OVERALL BEST MOISTURE FORECAST OVER THE WESTERN PIEDMONT. GIVEN THE
WEAKENING MID-LEVEL WAVE MOVING INTO THE AREA...850MB LIFT IS WEAK
AS WELL...WITH LIMITED DIFFLUENCE ALOFT. MOISTURE FIELDS...NOTABLY K
INDICES WHICH ARE ONLY IN THE TEENS DURING THE DAY OVER THE COASTAL
PLAIN ON THE GFS...INDICATE A DEFINITE TREND OF HIGHER MOISTURE
TOWARD THE YADKIN RIVER AND LEAST TOWARD THE COASTAL PLAIN...THE
FORMER WHERE THE BEST OF THE WEAK LIFT LIES. BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS ARE MORE UNSTABLE TOWARD KGSO THAN TOWARD
KRDU AND ESPECIALLY TOWARD KRWI. MLCAPE IS SLENDER AND FORECAST TO
BE 1000J/KG OR LESS IN CENTRAL NORTH CAROLINA SATURDAY...SO
CURRENTLY STRONG STORMS ARE NOT EXPECTED...BUT GIVEN THE AVAILABLE
MOISTURE AND INSTABILITY EVEN WITH MODEST SUPPORT ALOFT...ANTICIPATE
SCATTERED SHOWERS AND ISOLATED-TO-SCATTERED THUNDERSTORMS OVER THE
WESTERN PIEDMONT. THE CURRENT FORECAST HAS A SLIGHT CHANCE OF A
SHOWER OR THUNDERSTORM IN MOST AREAS FROM U.S. 1 EAST AND WILL NOT
WAFFLE OUT A SLIGHT CHANCE CURRENTLY WITH STATISTICAL GUIDANCE IN
THE 20S THROUGHOUT CENTRAL NORTH CAROLINA AT A MINIMUM...BUT WILL
ONLY HAVE CHANCES AT THE THRESHOLD OF SLIGHT FOR MOST AREAS EAST OF
A LINE FROM ABOUT KMEB TO KHNZ. ANY SHOWERS AND THUNDERSTORMS SHOULD
TEND TO DIMINISH DIURNALLY...WITH THE GREATER POTENTIAL AGAIN FOR A
FEW SHOWERS CONTINUING INTO THE OVERNIGHT HOURS OVER THE WESTERN
PIEDMONT. THERE...ANTICIPATE MOSTLY CLOUDY CONDITIONS ON AVERAGE IN
THE HIGHER 850MB MOISTURE SATURDAY...AND HIGHER MID-LEVEL MOISTURE
IN PLACE SATURDAY NIGHT. HIGHS IN THE 80S OVER THE FAR WESTERN
PIEDMONT...AROUND 90 FOR MOST AREAS FROM U.S. 1 EAST. OVERNIGHT LOWS
SATURDAY NIGHT UPPER 60S TO AROUND 70.
SUNDAY THROUGH WEDNESDAY...CENTRAL NORTH CAROLINA SHOULD BE IN A
WEAK TROUGH OR FRONTAL ZONE SUNDAY INTO MONDAY...WITH THE
CONVERGENCE APPEARING TO WEAKEN ON THE GFS AND SHIFTING EAST FROM
SUNDAY INTO MONDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS SHOULD BE
GOOD SUNDAY...GRADUALLY DIMINISHING OVERNIGHT SUNDAY AND SHIFTING
EAST FOR MONDAY. BY TUESDAY...MUCH OF CENTRAL NORTH CAROLINA IS IN A
RELATIVE MINIMUM OF MEAN MOISTURE AND IT WOULD APPEAR...IN THIS PART
OF THE LONG TERM PERIOD...TUESDAY WOULD HAVE THE LEAST CHANCE FOR
SHOWERS AND THUNDERSTORMS. MOISTURE RETURNS BY WEDNESDAY WITH WEAK
LOW PRESSURE AND LOWERING HEIGHTS IN THE BASE OF A LONG-WAVE
TROUGH...RENEWING SOLID CHANCES FOR SHOWERS AND THUNDERSTORMS AT THE
END OF THE LONG-TERM PERIOD. HIGH TEMPERATURES SHOULD MOSTLY RANGE
FROM 85 TO 90 DEGREES...AVERAGING NEAR THE HIGHER END OF THAT RANGE
WITH A FEW VALUES SLIGHTLY ABOVE 90 POSSIBLE ON THE CURRENTLY
EXPECTED DRIER DAYS OF MONDAY AND TUESDAY. OVERNIGHT LOWS MAINLY
WITHIN A DEGREE OR THREE OF 70.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM THURSDAY...
VERY SLOW IMPROVEMENT FROM MVFR TO VFR BY SUNSET. AS A COLD FRONT
HAS SETTLED JUST SOUTH OF THE AREA... INCOMING COOLER AIR FROM THE
NORTH AND LOW LEVEL MOISTURE HAVE LED TO QUICK CLOUD DEVELOPMENT
THIS MORNING WITH MVFR CIGS OVER ALL OF CENTRAL NC. THIS FAIRLY
THICK DECK OF CLOUDS WILL BE SLOW TO LIFT AS COOL STABLE LOW LEVEL
AIR CONTINUES TO ADVECT INTO CENTRAL NC FROM THE NNE... SO EXPECT
MVFR CONDITIONS TO HOLD UNTIL 22Z-00Z... WHEN CIGS ARE EXPECTED TO
CLIMB JUST ABOVE 3 KFT. A FEW SHOWERS MAY AFFECT RDU/RWI/FAY BUT ARE
UNLIKELY TO REACH ENOUGH COVERAGE TO BE A PREVAILING CONDITION. VFR
CONDITIONS ARE EXPECTED TO THEN DOMINATE FROM 00Z THROUGH THE END OF
THE TAF PERIOD WITH CIGS JUST ABOVE 3 KFT. WINDS FROM THE NORTHEAST
AT 8-12 KTS MAY PERIODICALLY GUST TO 14-18 KTS UNTIL 00Z THIS
EVENING... THEN WILL BECOME LIGHT/VARIABLE UNDER 6 KTS THROUGH 18Z
FRIDAY.
LOOKING BEYOND 18Z FRIDAY... VFR CONDITIONS WILL HOLD HEADING INTO
THE WEEKEND... ALTHOUGH IFR CIGS ARE POSSIBLE AT INT/GSO LATE FRIDAY
NIGHT INTO SATURDAY MORNING... AND SCATTERED SHOWERS/STORMS
GENERATING MVFR CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON THROUGH
SUNDAY EVENING... AHEAD OF AN APPROACHING FRONT. WITH WEAK HIGH
PRESSURE BUILDING IN BEHIND THE FRONT... DRY WEATHER AND VFR
CONDITIONS ARE EXPECTED LATE SUNDAY NIGHT THROUGH TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...DJF
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
743 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH ACROSS THE AREA THIS MORNING. THE
FRONT WILL STALL OFFSHORE THEN RETURN NORTH LATE SATURDAY. ANOTHER
COLD FRONT WILL APPROACH THE AREA EARLY NEXT WEEK. UNSETTLED
WEATHER IS EXPECTED FOR MUCH OF THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
INTERESTING SCENARIO THIS MORNING AND FOR THE NEAR TERM.
APPROACHING COLD FRONT IS HARD TO PICK OUT IN THE VERY BROAD
TROUGH OF LOW PRESSURE THAT NOW ENCOMPASSES MUCH OF THE ATLANTIC
COASTAL STATES AND OFFSHORE. WINDS HAVE TURNED NW MOST LOCATIONS
BUT THIS SEEM TO BE FOLLOWING FROM AN OUTFLOW BOUNDARY THROWN OFF
BY A LARGE AREA OF CONVECTION TO OUR NW. BEST GUESS IS THAT COLD
FRONT IS NOW ENTERING THE COASTAL PLAINS OF THE CAROLINAS FROM THE
NW. RADAR AND SATELLITE LOOPS SHOW A BROAD CIRCULATION DEVELOPING
WITHIN THE TROUGH OFFSHORE OF THE CAROLINAS SE OF CAPE FEAR. THIS
IS FORECAST BY THE MODELS...WHICH PULL IT TO THE NE THROUGH THE
NEAR TERM. NW FLOW WILL STRENGTHEN IN ITS WAKE...ALLOWING AN
ACTUAL SURGE OF SO-CALLED COLD...MORE LIKE COOL.. ADVECTION TO
TAKE PLACE LATE IN THE PERIOD. THIS WILL ALLOW OVERNIGHT
TEMPERATURES TO DROP BELOW NORMAL...UPPER 60S TO AROUND 70 MOST
PLACES FOR MINIMUMS. TODAYS TEMPERATURES LIKEWISE A BIT BELOW
NORMAL...WITH UPPER 80S MOST LOCATIONS.
WATER VAPOR LOOPS SHOW SIGNIFICANT DRYING IN THE WAKE OF THE COLD
FRONT. MODEL SOUNDINGS SHOW PRECIPITABLE WATERS VALUES CRASHING
THROUGH THE PERIOD AS THE MID AND UPPER LEVELS DRY OUT...WITH
CONTENTS DOWN NEAR AN INCH BY DAYBREAK FRIDAY AS COMPARED TO PRESENT
2 IN VALUES. LOWER LEVELS WILL STILL BE MOIST ENOUGH FOR CONVECTION
TODAY AND POSSIBLY THIS EVENING...BUT NO MORE THAN ISOLATED TO
SCATTERED ACTIVITY EXPECTED GIVEN DRY AIR MOVING IN ALOFT. SURFACE
DEWPOINTS WILL HOVER AROUND 70 MOST OF THE DAY BEFORE FINALLY
FALLING OVERNIGHT. THE AFTER MIDNIGHT PERIOD IS EXPECTED TO BE DRY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...COLD FRONT WILL REMAIN STALLED OFF THE
COAST FOR MUCH OF THE PERIOD. DEEP DRY AIR AND COOL LOW LEVEL
NORTHERLY FLOW FRI WILL KEEP TEMPERATURES BELOW CLIMO AND LIMIT
PRECIP CHANCES. LOW LEVEL STABILITY AND SUBSIDENCE/DRY AIR
ALOFT...IN THE WAKE OF EXITING 5H TROUGH...SHOULD PREVENT DEEP
CONVECTION. CANNOT RULE OUT AN ISOLATED WEAK SHOWER ALONG THE SEA
BREEZE BUT DO NOT FEEL MENTIONABLE POP IS WARRANTED. HAVE DECIDED
TO DROP POP TO 10 OR LESS FRI AND FRI NIGHT.
DEEP 5H LOW MOVING OVER THE GREAT LAKES SAT INDUCES 5H TROUGHING
OVER THE SOUTHEAST. TROUGH AXIS WILL REMAIN WEST OF THE AREA
THROUGH THE END OF THE PERIOD WITH SOUTHWEST FLOW STARTING
MOISTURE RETURN AS EARLY AS LATE FRI NIGHT. PRECIPITABLE WATER
VALUES CLIMB FROM 1.2 FRI TO 1.8 SAT EVENING. WEAK SURFACE
GRADIENT RESULTS IN SEA BREEZE DEVELOPMENT SAT AFTERNOON WHICH
HELPS PUSH REMAINS OF STALLED FRONT BACK TO THE COAST. THE SEA
BREEZE AND SURFACE BOUNDARY MAY HELP GENERATE SOME CONVECTION
LATE SAT. HAVE MAINTAIN MENTION OF POP IN FORECAST BUT GIVEN
LIMITING FACTORS HAVE DROPPED THEM DOWN TO SLIGHT CHC.
TEMPERATURES REMAIN BELOW CLIMO FOR THE SECOND HALF OF THE PERIOD
DESPITE DEVELOPMENT OF WEAK LOW LEVEL SOUTHERLY FLOW LATER SAT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...DEEP 5H LOW SLOWLY CROSSING THE GREAT LAKES
EARLY NEXT WEEK WILL LEAD TO UNSETTLED CONDITIONS ACROSS THE
CAROLINAS FOR MUCH OF THE PERIOD. WEAK BUT LARGE SCALE TROUGHING
ALOFT STEEPENS LAPSE RATES WITH WEAK FEATURES ROTATING THROUGH THE
TROUGH ENHANCING LIFT. ENVIRONMENT WILL BE MOIST WITH PRECIPITABLE
WATER VALUES AROUND OR ABOVE 2 INCHES FOR MUCH OF THE PERIOD. IN
ADDITION A COLD FRONT WILL DROP INTO THE AREA AND STALL ACROSS OR
JUST WEST OF THE AREA LATE MON OR TUE. INHERITED HIGH CHC DIURNAL
POP STILL APPEARS VALID. TRYING TO DELINEATE FAVORED POP TIME ANY
FURTHER BASED ON POTENTIAL WAVES OR SURFACE BOUNDARIES SEVERAL DAYS
OUT IS QUITE DIFFICULT AT BEST. GIVEN THE PRESENCE OF A SURFACE
BOUNDARY AND STEEPER MID LEVEL LAPSE RATES CONVECTION MAY LINGER
LONGER INTO THE OVERNIGHT HOURS THAN WOULD NORMALLY BE
EXPECTED...ESPECIALLY IF SHORTWAVES ARRIVE AT THE RIGHT TIME. WILL
CONTINUE TO CARRY LOW CHC POP OVERNIGHT.
TEMPERATURES WILL REMAIN WITHIN A FEW DEGREES OF CLIMO NEXT WEEK.
WEAK 5H TROUGHING AND CLOUD COVER WILL KEEP HIGHS SLIGHTLY BELOW
CLIMO FOR MUCH OF THE PERIOD. LINGERING CLOUDS AND MOISTURE WILL
KEEP LOWS SLIGHTLY ABOVE CLIMO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS THE FORECAST
AREA THIS MORNING WITH PREVAILING NORTHERLY FLOW AT ALL TERMS. RADAR
INDICATES SOME LIGHT PCPN ACTIVITY IS CURRENTLY NEAR KLBT...AND
TEMPO MVFR/IFR CIGS ARE POSSIBLE HERE IN THE NEAR TERM. WILL INCLUDE
VCSH FOR THE INLAND SITES THROUGH THE MORNING HOURS BASED ON CURRENT
RADAR TRENDS. WATER VAPOR IMAGERY AND FCST SOUNDINGS DEPICT DRIER
AIR MOVING IN THIS AFTN BEHIND THE FRONT...AND THE LATEST HRRR RUNS
SHOW VERY LITTLE IN THE WAY OF PCPN TODAY. ALONG THE COAST...WILL
INTRODUCE VCSH IN THE EARLY AFTN AS ISOLATED SHOWERS CANNOT BE RULED
OUT. BUT OVERALL PCPN COVERAGE SHOULD BE LIMITED BY MID-LEVEL DRYING
THROUGH THE AFTN/EVENING HOURS. THE WINDS WILL REMAIN N/NE AOB 10
KTS TODAY. DO NOT ANTICIPATE ANY FOG/STRATUS IMPACTS FOR THE
OVERNIGHT HOURS ATTM.
EXTENDED OUTLOOK...ISOLATED SHOWERS/T-STORMS SATURDAY...INCREASING
IN COVERAGE SUNDAY AND MONDAY AS ANOTHER FRONT APPROACHES THE CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LIGHT WINDS WITH SEAS IN THE 2 FT RANGE OVER THE WATERS THROUGH
THE PERIOD AS A COMPLEX SYSTEM WITH A WEAK GRADIENT MOVES ACROSS
THE WATERS. A BROAD AREA OF LOW PRESSURE IS FORMING IVER THE
WATERS THIS MORNING...LEADING TO VARIABLE WINDS. THESE WINDS WILL
TURN MORE NORTHERLY LATER THIS MORNING AS A COLD FRONT MOVES
ACROSS THE WATERS. WINDS WILL REMAIN LIGHT HOWEVER...WITH SEAS
HOVERING IN THE 2 FT RANGE THROUGH THE OVERNIGHT PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...COLD FRONT WILL BE STALLED EAST OF THE
WATERS INTO SAT WITH LIGHT NORTHERLY FLOW OVER THE WATERS. WEAK
GRADIENT WILL ALLOW DEVELOPMENT OF SEA BREEZE...WHICH WILL END UP
PUSHING THE REMAINS OF THE FRONT INLAND SAT EVENING. LIGHT
SOUTHERLY FLOW DEVELOPS LATE SAT AND SAT NIGHT. GRADIENT REMAINS
WEAK THROUGH THE PERIOD AND SPEEDS ARE EXPECTED TO REMAIN 10 KT OR
LESS. SEAS AROUND 2 FT INTO SAT WILL BUILD TO 2 TO 3 FT SAT NIGHT
AS ONSHORE FLOW DEVELOPS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...LIGHT SOUTH TO SOUTHWEST FLOW WILL PERSIST
THROUGH THE PERIOD. BERMUDA HIGH REMAINS ANCHORED OFF THE COAST
WHILE INLAND DISSIPATING BOUNDARY SUN WILL BE SUPERSEDED BY SLOW
MOVING COLD FRONT MON. THIS WILL INCREASE THE GRADIENT DURING THE
SECOND HALF OF THE PERIOD...RESULTING IN A SLIGHT INCREASE IN WIND
SPEEDS. ON SUN SPEEDS WILL BE 10 KT OR LESS THEN INCREASE TO 10 TO
15 KT FOR MON. SEAS WILL RUN 2 TO 3 FT...MOSTLY AS WIND WAVE.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 AM THURSDAY...HAVE ISSUED ANOTHER COASTAL FLOOD ADVISORY
FOR THE CAPE FEAR RIVER IN THE VICINITY OF WILMINGTON FOR TONIGHT.
HIGH TIDE IS PREDICTED FOR 12:58 AM FRIDAY AND EXPECT THE RIVER
LEVEL AT THE TIDE GAUGE IN DOWNTOWN WILMINGTON TO TOP OUT JUST
BELOW 6 FT. THIS IS ABOUT A HALF FOOT ABOVE MINOR FLOOD STAGE
CRITERIA.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 2 AM EDT
FRIDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
MARINE...REK/III
TIDES/COASTAL FLOODING...REK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
947 PM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 947 PM CDT FRI JUL 26 2013
HIGH PRESSURE CONTINUES TO SETTLE ACROSS THE NORTHERN PLAINS THIS
EVENING GENERATING LIGHT WINDS AND CLEAR SKIES. TEMPERATURES ARE
STILL EXPECTED TO RADIATE TO RECORD LOWS (LOWER 40S) OVER BISMARCK
AND JAMESTOWN BY EARLY SATURDAY MORNING. SEE TABLE IN THE SHORT
TERM SECTION BELOW FOR FORECAST AND RECORD LOWS FOR OTHER SELECTED
CITIES IN WESTERN AND CENTRAL NORTH DAKOTA.
OTHERWISE...NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST.
THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 657 PM CDT FRI JUL 26 2013
NOT TOO MANY CHANGES WERE MADE TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
RECORD LOWS STILL LOOK TO BE ON TRACK FOR BISMARCK AND JAMESTOWN
TONIGHT. SEE TABLE IN THE SHORT TERM DISCUSSION BELOW FOR FORECAST
AND RECORD LOWS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
NO PRECIPITATION FOR THE SHORT TERM PERIOD...WITH THE MAIN
CHALLENGE BEING RECORD COLD TEMPERATURES FOR SATURDAY
MORNING...MAINLY FOR BISMARCK AND JAMESTOWN.
LATEST VISIBLE SATELLITE IMAGERY SHOWS SCT/BKN CUMULUS FIELD
COVERING ALL OF NORTH DAKOTA. CYCLONIC FLOW WITH AN UPSTREAM
SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN WILL MAINTAIN THE
CUMULUS FIELD THROUGH THE EVENING...AND AFTER SUNSET WILL SEE A
GRADUAL REDUCTION IN CLOUDS WITH CLEAR SKIES COMMENCING LATER
TONIGHT. THE SHORTWAVE IS EXPECTED TO MAKE IT TO AROUND STANLEY BY
00Z SATURDAY...THEN INTO THE JAMES RIVER VALLEY BY 06Z SATURDAY.
THE GFS AND TO SOME EXTENT THE RAP AND HRRR TRY TO DEVELOP A
COUPLE SHOWERS IN THE SOUTHWEST AND ALSO IN THE NORTHEAST/TURTLE
MOUNTAINS THIS AFTERNOON...BUT HAVE OPTED TO KEEP IT DRY WITH
REGIONAL RADAR AND SURFACE OBSERVATIONS CONTINUING TO SHOW A VOID
IN ANY PRECIPITATION DEVELOPMENT UP TO THIS POINT. A 1030MB
SURFACE HIGH PRESSURE OVER SOUTHEASTERN SASKATCHEWAN WILL ALSO
SHIFT SOUTHEAST INTO EAST CENTRAL NORTH DAKOTA...AND INTO THE
LOWER JAMES RIVER VALLEY BY 12Z SATURDAY. UPSTREAM LOW
TEMPERATURES IN SOUTH CENTRAL CANADA FRIDAY MORNING RANGED FROM
38F TO 42F...WHICH IS IN THE BALLPARK OF WHAT THE MET/MAV GUIDANCE
IS FOR CENTRAL NORTH DAKOTA. THE OLD RULE OF THUMB USING THE
MINIMUM DEWPOINT DURING THE MAX TEMPERATURE FOR OBTAINING AN
APPROXIMATE LOW TEMPERATURE ALSO SUPPORTS LOWS BETWEEN 39F AND
44F. CONFIDENCE IS HIGH FOR RECORD LOWS IN BISMARCK AND
JAMESTOWN...WITH MINOT...WILLISTON...AND DICKINSON COMING JUST SHY
OF ESTABLISHING NEW RECORD LOWS.
RECORD LOW TEMPERATURES FOR SATURDAY JULY 27 ARE AS FOLLOWS...
CITY RECORD LOW/DATE FORECAST LOW TEMP
BISMARCK 43F/1994 41F
JAMESTOWN 44F/1904 41F
MINOT 40F/1925 42F
WILLISTON 40F/1908 43F
DICKINSON 40F/1971 43F
CONSIDERING THE LOCATION OF THE SURFACE HIGH...EAST CENTRAL NORTH
DAKOTA AND INTO THE SOUTHERN JAMES RIVER VALLEY...THIS IS THE
OPTIMAL LOCATION FOR OBTAINING THE COLDEST TEMPERATURES ACROSS
SOUTH CENTRAL NORTH DAKOTA...BISMARCK AND JAMESTOWN. UPSTREAM
OBSERVATIONS IN SOUTH CENTRAL CANADA ALSO HAD SOME PATCHY FOG FRIDAY
MORNING AND HAVE ADDED THAT TO THE FORECAST...MAINLY ALONG AND
JUST EAST OF HIGHWAY 83.
FOR SATURDAY...SUNNY WEST...AND MOSTLY SUNNY SKIES CENTRAL.
EXPECT MID TO LATE MORNING CUMULUS AGAIN DEVELOPING OVER CENTRAL
NORTH DAKOTA WITH WEAK CYCLONIC FLOW...BUT SOUNDINGS SHOW DRY
AIR/SUBSIDENCE ALOFT WILL BECOME MUCH STRONGER..AND THIS WILL
INHIBIT ANY FURTHER BUILD UPS FOR THE AFTERNOON. THE RESULT WILL
BE A SCATTERED FAIR WEATHER CUMULUS FIELD EARLY ON...THEN
DISSIPATING THROUGH THE AFTERNOON. AFTERNOON HIGHS AROUND 70F
CENTRAL TO THE MID 70S WEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
WE TRANSITION FROM A COOL AND DRY PERIOD BACK TO A WARMER AND
ACTIVE PERIOD FOR THE BEGINNING OF THE LONG TERM PERIOD.
AFTERWARDS...A RETURN TO A RELATIVELY QUIET PERIOD IS EXPECTED
THROUGH THE MIDDLE PORTIONS OF THE WORK WEEK UNTIL LATER NEXT WEEK
WHEN WE MAY SEE INCREASING CHANCES FOR MORE WIDESPREAD
PRECIPITATION.
RETURN FLOW INCREASES OVER WESTERN NORTH DAKOTA SATURDAY NIGHT AS
SURFACE HIGH PRESSURE SLOWLY MOVES EAST TOWARDS THE UPPER
MISSISSIPPI VALLEY...AND A SFC TROUGH DEVELOPS IN THE LEE OF THE
MONTANA ROCKIES AHEAD OF A LONG WAVE TROUGH MOVING INTO ALBERTA.
LATEST 12Z MODELS HAVE AGAIN SLOWED DOWN THE EASTWARD PROGRESSION
OF THE SURFACE TROUGH OVER EASTERN MONTANA...AND NOW KEEP ALL
PRECIPITATION OFF TO OUR WEST THROUGH SUNDAY MORNING. AS A RESULT
I HAVE REMOVED ALL MENTION OF THUNDERSTORMS THROUGH 18Z SUNDAY.
SHORT WAVE MID LEVEL RIDGE MOVING ACROSS THE REGION ON SUNDAY WILL
BRING WARMER AIR TO WEST AND CENTRAL NORTH DAKOTA...WITH DAYTIME
HIGHS WARMING BACK TOWARDS THE 80 DEGREE MARK WEST AND MID TO
UPPER 70S CENTRAL. WE START TO SEE INCREASING INSTABILITY OVER THE
FAR WESTERN COUNTIES SUNDAY AFTERNOON AS RETURN FLOW CONTINUES
HELPING LOW LEVEL MOISTURE MOVE BACK INTO THE NORTHERN PLAINS.
WHILE I HAVE KEPT SOME MENTION FOR AFTERNOON CONVECTION IN THE
FORECAST ACROSS THE WEST...12Z NAM/GFS BUFFER SOUNDINGS INDICATE
WE WILL BE STRONGLY CAPPED SO WILL CONSIDER TRENDING SUNDAY
AFTERNOON DRY WITH FUTURE FORECAST PACKAGES.
AS THE RIDGE CONTINUES EASTWARD...FLOW ALOFT WILL TRANSITION TO MORE
WEST/SOUTHWESTERLY SUNDAY NIGHT THROUGH MONDAY AND INTO MONDAY NIGHT
ALONG WITH FAVORABLY INSTABILITY FOR THUNDERSTORMS SPREADING ACROSS
THE STATE. COMBINED WITH THE SURFACE TROUGH PUSHING EAST ACROSS THE
DAKOTAS...EXPECT TO SEE A RATHER ACTIVE CONVECTIVE PERIOD FROM
LATE SUNDAY NIGHT THROUGH MONDAY EVENING. AS FAR AS SEVERE
WEATHER...LINGERING CLOUDS FROM SUNDAY NIGHTS EXPECTED CONVECTION
COULD VERY WELL LIMIT THE SEVERE POTENTIAL...FOR MONDAY.
HOWEVER...LATEST MODELS ARE NOW INCREASING THE POTENTIAL FOR
SCATTERED STRONG TO SEVERE STORMS...ESPECIALLY MONDAY
AFTERNOON/EVENING. WILL MENTION THIS POSSIBILITY IN THE HWO. IT
SHOULD BE NOTED THE 12Z NAM...WHILE A FAST OUTLIER...WOULD FAVOR
THE MOST ACTIVE PERIOD LATE SUNDAY EVENING THROUGH MONDAY
AFTERNOON. THUS WILL NEED TO KEEP AN EYE ON THE MODEL TRENDS THE
NEXT FEW PERIODS.
AFTER THIS SHORT PERIOD OF ACTIVE WEATHER...MODELS FORECAST A RETURN
TO A QUIETER WEATHER PERIOD TUESDAY INTO MID-WEEK WITH NORTHWEST
FLOW ALOFT REDEVELOPING FOLLOWED BY ANOTHER S/WV RIDGE. WHILE CANNOT
RULE OUT ISOLATED SHOWERS/THUNDERSTORMS...THE OVERALL PATTERN
TUESDAY-THURSDAY WOULD NOT SUPPORT WIDESPREAD PRECIPITATION. AS WE
PROCEED TOWARDS THE END OF THE WORK WEEK INTO THE FOLLOWING
WEEKEND...BOTH THE 12Z GFS/ECMWF DEPICT ANOTHER ACTIVE WEATHER
PERIOD DEVELOPING AS FLOW BECOMES QUASI-ZONAL AGAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 657 PM CDT FRI JUL 26 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER WESTERN AND CENTRAL
NORTH DAKOTA THROUGH THE TAF PERIOD. TEMPO MVFR CONDITIONS WILL BE
POSSIBLE OVERNIGHT. HOWEVER...GIVEN THE TIMING AND COVERAGE
UNCERTAINTIES...ONLY INDICATED SCT MVFR CLOUD BASES IN EACH TAF
FOR TONIGHT. OTHERWISE...WINDS WILL CONTINUE TO GRADUALLY VEER TO
EASTERLY/SOUTHEASTERLY THROUGH THE PERIOD AS HIGH PRESSURE CRESTS
ACROSS THE REGION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...NH
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
657 PM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 657 PM CDT FRI JUL 26 2013
NOT TOO MANY CHANGES WERE MADE TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
RECORD LOWS STILL LOOK TO BE ON TRACK FOR BISMARCK AND JAMESTOWN
TONIGHT. SEE TABLE IN THE SHORT TERM DISCUSSION BELOW FOR FORECAST
AND RECORD LOWS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
NO PRECIPITATION FOR THE SHORT TERM PERIOD...WITH THE MAIN
CHALLENGE BEING RECORD COLD TEMPERATURES FOR SATURDAY
MORNING...MAINLY FOR BISMARCK AND JAMESTOWN.
LATEST VISIBLE SATELLITE IMAGERY SHOWS SCT/BKN CUMULUS FIELD
COVERING ALL OF NORTH DAKOTA. CYCLONIC FLOW WITH AN UPSTREAM
SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN WILL MAINTAIN THE
CUMULUS FIELD THROUGH THE EVENING...AND AFTER SUNSET WILL SEE A
GRADUAL REDUCTION IN CLOUDS WITH CLEAR SKIES COMMENCING LATER
TONIGHT. THE SHORTWAVE IS EXPECTED TO MAKE IT TO AROUND STANLEY BY
00Z SATURDAY...THEN INTO THE JAMES RIVER VALLEY BY 06Z SATURDAY.
THE GFS AND TO SOME EXTENT THE RAP AND HRRR TRY TO DEVELOP A
COUPLE SHOWERS IN THE SOUTHWEST AND ALSO IN THE NORTHEAST/TURTLE
MOUNTAINS THIS AFTERNOON...BUT HAVE OPTED TO KEEP IT DRY WITH
REGIONAL RADAR AND SURFACE OBSERVATIONS CONTINUING TO SHOW A VOID
IN ANY PRECIPITATION DEVELOPMENT UP TO THIS POINT. A 1030MB
SURFACE HIGH PRESSURE OVER SOUTHEASTERN SASKATCHEWAN WILL ALSO
SHIFT SOUTHEAST INTO EAST CENTRAL NORTH DAKOTA...AND INTO THE
LOWER JAMES RIVER VALLEY BY 12Z SATURDAY. UPSTREAM LOW
TEMPERATURES IN SOUTH CENTRAL CANADA FRIDAY MORNING RANGED FROM
38F TO 42F...WHICH IS IN THE BALLPARK OF WHAT THE MET/MAV GUIDANCE
IS FOR CENTRAL NORTH DAKOTA. THE OLD RULE OF THUMB USING THE
MINIMUM DEWPOINT DURING THE MAX TEMPERATURE FOR OBTAINING AN
APPROXIMATE LOW TEMPERATURE ALSO SUPPORTS LOWS BETWEEN 39F AND
44F. CONFIDENCE IS HIGH FOR RECORD LOWS IN BISMARCK AND
JAMESTOWN...WITH MINOT...WILLISTON...AND DICKINSON COMING JUST SHY
OF ESTABLISHING NEW RECORD LOWS.
RECORD LOW TEMPERATURES FOR SATURDAY JULY 27 ARE AS FOLLOWS...
CITY RECORD LOW/DATE FORECAST LOW TEMP
BISMARCK 43F/1994 41F
JAMESTOWN 44F/1904 41F
MINOT 40F/1925 42F
WILLISTON 40F/1908 43F
DICKINSON 40F/1971 43F
CONSIDERING THE LOCATION OF THE SURFACE HIGH...EAST CENTRAL NORTH
DAKOTA AND INTO THE SOUTHERN JAMES RIVER VALLEY...THIS IS THE
OPTIMAL LOCATION FOR OBTAINING THE COLDEST TEMPERATURES ACROSS
SOUTH CENTRAL NORTH DAKOTA...BISMARCK AND JAMESTOWN. UPSTREAM
OBSERVATIONS IN SOUTH CENTRAL CANADA ALSO HAD SOME PATCHY FOG FRIDAY
MORNING AND HAVE ADDED THAT TO THE FORECAST...MAINLY ALONG AND
JUST EAST OF HIGHWAY 83.
FOR SATURDAY...SUNNY WEST...AND MOSTLY SUNNY SKIES CENTRAL.
EXPECT MID TO LATE MORNING CUMULUS AGAIN DEVELOPING OVER CENTRAL
NORTH DAKOTA WITH WEAK CYCLONIC FLOW...BUT SOUNDINGS SHOW DRY
AIR/SUBSIDENCE ALOFT WILL BECOME MUCH STRONGER..AND THIS WILL
INHIBIT ANY FURTHER BUILD UPS FOR THE AFTERNOON. THE RESULT WILL
BE A SCATTERED FAIR WEATHER CUMULUS FIELD EARLY ON...THEN
DISSIPATING THROUGH THE AFTERNOON. AFTERNOON HIGHS AROUND 70F
CENTRAL TO THE MID 70S WEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
WE TRANSITION FROM A COOL AND DRY PERIOD BACK TO A WARMER AND
ACTIVE PERIOD FOR THE BEGINNING OF THE LONG TERM PERIOD.
AFTERWARDS...A RETURN TO A RELATIVELY QUIET PERIOD IS EXPECTED
THROUGH THE MIDDLE PORTIONS OF THE WORK WEEK UNTIL LATER NEXT WEEK
WHEN WE MAY SEE INCREASING CHANCES FOR MORE WIDESPREAD
PRECIPITATION.
RETURN FLOW INCREASES OVER WESTERN NORTH DAKOTA SATURDAY NIGHT AS
SURFACE HIGH PRESSURE SLOWLY MOVES EAST TOWARDS THE UPPER
MISSISSIPPI VALLEY...AND A SFC TROUGH DEVELOPS IN THE LEE OF THE
MONTANA ROCKIES AHEAD OF A LONG WAVE TROUGH MOVING INTO ALBERTA.
LATEST 12Z MODELS HAVE AGAIN SLOWED DOWN THE EASTWARD PROGRESSION
OF THE SURFACE TROUGH OVER EASTERN MONTANA...AND NOW KEEP ALL
PRECIPITATION OFF TO OUR WEST THROUGH SUNDAY MORNING. AS A RESULT
I HAVE REMOVED ALL MENTION OF THUNDERSTORMS THROUGH 18Z SUNDAY.
SHORT WAVE MID LEVEL RIDGE MOVING ACROSS THE REGION ON SUNDAY WILL
BRING WARMER AIR TO WEST AND CENTRAL NORTH DAKOTA...WITH DAYTIME
HIGHS WARMING BACK TOWARDS THE 80 DEGREE MARK WEST AND MID TO
UPPER 70S CENTRAL. WE START TO SEE INCREASING INSTABILITY OVER THE
FAR WESTERN COUNTIES SUNDAY AFTERNOON AS RETURN FLOW CONTINUES
HELPING LOW LEVEL MOISTURE MOVE BACK INTO THE NORTHERN PLAINS.
WHILE I HAVE KEPT SOME MENTION FOR AFTERNOON CONVECTION IN THE
FORECAST ACROSS THE WEST...12Z NAM/GFS BUFFER SOUNDINGS INDICATE
WE WILL BE STRONGLY CAPPED SO WILL CONSIDER TRENDING SUNDAY
AFTERNOON DRY WITH FUTURE FORECAST PACKAGES.
AS THE RIDGE CONTINUES EASTWARD...FLOW ALOFT WILL TRANSITION TO MORE
WEST/SOUTHWESTERLY SUNDAY NIGHT THROUGH MONDAY AND INTO MONDAY NIGHT
ALONG WITH FAVORABLY INSTABILITY FOR THUNDERSTORMS SPREADING ACROSS
THE STATE. COMBINED WITH THE SURFACE TROUGH PUSHING EAST ACROSS THE
DAKOTAS...EXPECT TO SEE A RATHER ACTIVE CONVECTIVE PERIOD FROM
LATE SUNDAY NIGHT THROUGH MONDAY EVENING. AS FAR AS SEVERE
WEATHER...LINGERING CLOUDS FROM SUNDAY NIGHTS EXPECTED CONVECTION
COULD VERY WELL LIMIT THE SEVERE POTENTIAL...FOR MONDAY.
HOWEVER...LATEST MODELS ARE NOW INCREASING THE POTENTIAL FOR
SCATTERED STRONG TO SEVERE STORMS...ESPECIALLY MONDAY
AFTERNOON/EVENING. WILL MENTION THIS POSSIBILITY IN THE HWO. IT
SHOULD BE NOTED THE 12Z NAM...WHILE A FAST OUTLIER...WOULD FAVOR
THE MOST ACTIVE PERIOD LATE SUNDAY EVENING THROUGH MONDAY
AFTERNOON. THUS WILL NEED TO KEEP AN EYE ON THE MODEL TRENDS THE
NEXT FEW PERIODS.
AFTER THIS SHORT PERIOD OF ACTIVE WEATHER...MODELS FORECAST A RETURN
TO A QUIETER WEATHER PERIOD TUESDAY INTO MID-WEEK WITH NORTHWEST
FLOW ALOFT REDEVELOPING FOLLOWED BY ANOTHER S/WV RIDGE. WHILE CANNOT
RULE OUT ISOLATED SHOWERS/THUNDERSTORMS...THE OVERALL PATTERN
TUESDAY-THURSDAY WOULD NOT SUPPORT WIDESPREAD PRECIPITATION. AS WE
PROCEED TOWARDS THE END OF THE WORK WEEK INTO THE FOLLOWING
WEEKEND...BOTH THE 12Z GFS/ECMWF DEPICT ANOTHER ACTIVE WEATHER
PERIOD DEVELOPING AS FLOW BECOMES QUASI-ZONAL AGAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 657 PM CDT FRI JUL 26 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER WESTERN AND CENTRAL
NORTH DAKOTA THROUGH THE TAF PERIOD. TEMPO MVFR CONDITIONS WILL BE
POSSIBLE OVERNIGHT. HOWEVER...GIVEN THE TIMING AND COVERAGE
UNCERTAINTIES...ONLY INDICATED SCT MVFR CLOUD BASES IN EACH TAF
FOR TONIGHT. OTHERWISE...WINDS WILL CONTINUE TO GRADUALLY VEER TO
EASTERLY/SOUTHEASTERLY THROUGH THE PERIOD AS HIGH PRESSURE CRESTS
ACROSS THE REGION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...NH
AVIATION...TM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
948 PM EDT FRI JUL 26 2013
.SYNOPSIS...
PRECIPITATION CHANCES WILL REMAIN IN THE FORECAST THROUGH THE
WEEKEND AS A SERIES OF UPPER LEVEL DISTURBANCES AND A COLD FRONT
PASS THROUGH. CONDITIONS LOOK TO IMPROVE SLIGHTLY FOR THE START OF
NEXT WEEK AS SURFACE HIGH PRESSURE BUILDS WHILE REDUCING CHANCES FOR
PRECIPITATION.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 945 PM EDT FRIDAY...SHOWERS AND THUNDERSTORMS ARE GRADUALLY
INCREASING OVER NE GA...THE WRN UPSTATE AND THE CENTRAL AND SW NC
MTNS. THIS IS GENERALLY WHAT WAS EXPECTED...THOUGH IT/S A FEW HOURS
EARLIER THAN EXPECTED. I SUSPECT THAT THIS CONVECTION WILL CONTINUE
TO SLOWLY MOVE NORTHEAST THE REST OF THE NIGHT...AND IT/S POSSIBLE
THAT MORE WILL DEVELOP ALONG THE BLUE RIDGE AS THE LLVL FLOW
INCREASES LATE. THE STRENGTHENING WINDS WILL BE IN RESPONSE TO AN
APPROACHING SHORT WAVE WHICH SHOWS UP WELL ON THE RUC H5 ANALYSIS
AND THE WATER VAPOR IMAGERY PRETTY MUCH RIGHT OVER THE MISSISSIPPI
RIVER ATTM. LOCALLY HEAVY RAIN AND EVEN A SEVERE STORM ARE TWO STILL
LOOK LIKE A GOOD BET.
AS OF 600 PM EDT FRIDAY...UPPED POPS INTO THE LIKELY CATEGORY ACROSS
A BROAD SECTION OF THE CENTRAL PART OF THE FA LATER TONIGHT. MOST OF
THE CONVECTIVE ALLOWING MODELS DEVELOP SHOWERS AND THUNDERSTORMS
LATER TONIGHT AS THE LLVL FLOW INCREASES TO 20 TO 25 KTS AND A
RATHER POTENT SHORT WAVE APPROACHES FROM THE BEST. IT APPEARS THAT
RAIN CHANCES WILL BE HIGHEST ACROSS THE BLUE RIDGE AND OUT INTO THE
FOOTHILLS WHERE UPSLOPE WILL AID ASCENT. LOCALLY VERY HEAVY RAIN IS
POSSIBLE WITH THE STORMS...WHICH HAS BASICALLY BEEN THE STORY OF THE
SUMMER. WITH DRY MID-LEVEL AIR...A FEW AREAS OF LARGE HAIL DAMAGING
STRAIGHT LINE WINDS WILL ALSO BE POSSIBLE...ESPECIALLY EARLY ON IN
THE EVENT...SAY BETWEEN 8 PM AND MIDNIGHT.
PREVIOUS DISCUSSION...ISOLATED DEEP CONVECTION CONTINUES TO DEVELOP
ACROSS THE FOOTHILLS AND THE UPPER SAVANNAH RIVER VALLEY. A LACK OF
TRULY ROBUST INSTABILITY (DUE TO WARM MID-LEVEL TEMPS) IS LIMITING
THE VERTICAL DEVELOPMENT OF THE CONVECTION...AND THERE HAS BEEN NO
LIGHTNING ACTIVITY OBSERVED THUS FAR (IN FACT...CELLS HAVE NOT EVEN
COME CLOSE TO BEING ENOUGH TO PRODUCE LIGHTNING). NEVERTHELESS...CU
IS BEGINNING TO APPEAR SOMEWHAT AGITATED OVER THE HIGH TERRAIN...AND
AS THE ATM CONTINUES TO HEAT UP...COVERAGE AND INTENSITY OF
CONVECTION SHOULD GRADUALLY INCREASE. WE WILL CONTINUE TO ADVERTISE
A GRADUAL INCREASE IN POPS TO LOW/SOLID CHANCE ACROSS THE WESTERN
HALF OF THE AREA BY LATE AFTERNOON...WHILE HOLDING ON TO SLIGHT
COVERAGE AT BEST IN THE WEAKER INSTABILITY ACROSS OUR EASTERN
PIEDMONT ZONES.
THE SHORT TERM MODELS CONTINUE TO PICK UP ON A WEAK VORT MAX...
POSSIBLY CONVECTIVELY INDUCED AND A PRECURSOR TO THE PRIMARY SHORT
WAVE CURRENTLY APPROACHING THE MISS VALLEY...MOVING ACROSS THE CWA
THIS EVENING INTO THE EARLY PART OF THE OVERNIGHT. IN RESPONSE...
MOST MODELS...INCLUDING THE HIRES MODELS...HINT AT INCREASING
COVERAGE OF CONVECTION TONIGHT. OUR CURRENT EXPECTATION IS THAT THIS
WAVE WILL SWEEP THE MORE ROBUST CONVECTIVE ACTIVITY CURRENTLY
DEVELOPING OVER CENTRAL GEORGIA ACROSS THE WESTERN HALF OF THE CWA
THIS EVENING...SO WILL GENERALLY FEATURE 40-50 POPS ACROSS MUCH OF
THE AREA DURING THIS TIME. SHEAR IS WEAK AND INSTABILITY COULD
CERTAINLY BE BETTER...BUT AN ISOLATED PULSE SEVERE STORM WILL BE
POSSIBLE ALONG WITH THE THREAT OF HEAVY RAIN THREAT.
TOMORROW MAY BE AN INTERESTING DAY AS THE PRIMARY VORT MAX
APPROACHES FROM THE TENN VALLEY. DEEP LAYER FLOW WILL STRENGTHEN IN
ADVANCE OF THIS FEATURE SUCH THAT SHEAR IS QUITE RESPECTABLE FOR
MID-SUMMER (20-25 KTS 0-3 KM...30-35 KTS 0-6 KM). THE PRIMARY
CONCERN WILL BE WITH THE DEGREE OF INSTABILITY...AS THE
STRENGTHENING S/SE FLOW SHOULD ALSO RESULT IN PLENTY OF MORNING
STRATOCU. NEVERTHELESS...MODEL SOUNDINGS DEPICT QUITE A BIT OF
LINGERING DRY MID-LEVEL AIR...SO WE COULD SEE ENOUGH HEATING TO
REALIZE CLOSE TO 2000 J/KG CAPE VALUES. IF SO...WE MAY WELL SEE AN
ORGANIZED SEVERE WEATHER THREAT. CONSIDERING THE UNCERTAINTY ABOUT
THE DEGREE OF HEATING...THE CURRENT SPC /SEE TEXT/5 PERCENT AREA
APPEARS REASONABLE FOR DAY 2.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRI...NUMEROUS SHOWERS/THUNDERSTORMS SHOULD BE ON
GOING SAT EVENING OVER EASTERN SECTIONS...IN RESPONSE TO A VIGOROUS
VORT MAX MOVING THROUGH THE CAROLINAS. I EXPECT THAT THE MAIN BODY
OF SHOWERS/STORMS WILL MOVE EAST OF THE AREA BY MIDNIGHT.
HOWEVER...A WEAK COLD FRONT WILL SLIP SE TO THE LEE OF THE MOUNTAINS
BY DAYBREAK SUNDAY...SO WILL NEED TO HOLD ONTO SOME CHANCE POPS
OVERNIGHT FOR SOME UPSLOPE MOUNTAIN SHOWERS...AND PERHAPS SOME
SHOWERS AND THUNDERSTORMS INDUCED BY THE FRONT.
ON SUNDAY...THE FRONT WILL LINGER OVER THE REGION AS AN UPPER LOW
DIGS OVER THE GREAT LAKES. LOW LEVEL CONVERGENCE COMBINED WITH UPPER
DIFFLUENCE AND AFTERNOON CAPES PEAKING AROUND 1500J IN THE AFTERNOON
SHOULD BE ENOUGH FOR SCT TO NUMEROUS SHOWERS AND THUNDERSTORMS...
MOST NUMEROUS OVER EASTERN SECTIONS. SOME SHOWERS/STORMS COULD LINGER INTO
SUNDAY EVENING OVER THE EAST. HOWEVER...THE FRONT WILL FINALLY MOVE
EAST OF THE AREA OVERNIGHT WITH HIGH PRESSURE BUILDING IN FROM THE
WEST.
ON MONDAY...THE SURFACE HIGH IS FORECAST TO DOMINATE THE REGIONAL
WEATHER. THEREFORE...EXPECT A DRY DAY WITH MOSTLY CLEAR TO PARTLY
CLOUDY CONDITIONS. STAYED CLOSE TO CONSENSUS GUIDANCE FOR MOST GRID
FIELDS. MAX TEMPS WILL BE A COUPLE CATEGORIES BELOW AVERAGE ON
SUNDAY...WARMING TO ABOUT A CATEGORY BELOW AVERAGE MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...THE EXTENDED PERIOD BEGINS LATE MONDAY WITH
HIGH PRESSURE BUILDING IN OVER THE EAST COAST BEHIND THE DEPARTING
FRONTAL SYSTEM...USHERING IN DRIER AIR OVER THE CWA FOR THE
BEGINNING OF NEXT WEEK. THE COMBINATION OF INVERSIONS AND WARMER AIR
ALOFT SHOULD KEEP MOST OF THE AREA CAPPED THROUGH MIDWEEK...ALLOWING
ONLY FOR SLIGHT CHANCE POPS MONDAY AND CHANCE POPS TUESDAY
AFTERNOON. THE AIRMASS BEGINS TO SATURATE AGAIN BY WEDNESDAY AS
ANOTHER TROUGH DIPS DOWN...AND THE MOIST AIR COMBINED WITH AN
APPROACHING SHORTWAVE WILL MAKE FOR GREATEST POPS WEDNESDAY
AFTERNOON/EVENING. IMPROVED DEEP LAYER MOISTURE AND GENERAL
TROUGHINESS OVER THE SOUTHEASTERN CONUS WILL KEEP THE PATTERN
UNSETTLED WITH MORE DIURNALLY DRIVEN CONVECTION THROUGH THE END OF
NEXT WEEK.
CLOUD COVER AT THE BEGINNING OF THE PERIOD WILL KEEP HIGH TEMPS
BELOW AVERAGE...AND HIGHS WILL REMAIN COOLER THAN NORMAL THROUGH THE
END OF NEXT WEEK DUE TO LOWER THICKNESS ADVECTION. LOWS WILL BE NEAR
AVERAGE FOR THE ENTIRE MEDIUM RANGE.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...CU HAVE DRIED UP WITH THE LOSS OF HEATING AND THE AIRFIELD
SHOULD EXPERIENCE SEVERAL HOURS OF FAIR WEATHER. LATER TONIGHT
CONDITIONS WILL BE FAVORABLE FOR NOCTURNAL CONVECTION AND I HAVE A
TEMPO GROUP FOR TSTMS FROM 06-09 UTC. STILL EXPECT STRENGTHENING
SOUTHERLY FLOW ACTING UPON AN INCREASINGLY MOIST LOW LEVEL AIR MASS
TO RESULT IN THE DEVELOPMENT OF WIDESPREAD STRATUS ACROSS THE AREA
LATE TONIGHT. CIGS MAY BE LOWER TONIGHT WITH SOME PCPN IN THE AREA
AND I TAKE THEM DOWN TO BKN010 AT 0900 UTC. ONLY SLOW IMPROVEMENT IS
EXPECTED THROUGH THE MORNING HOURS WITH THE MOIST SE FLOW AND
POSSIBLE ONGOING SHOWER OR TSTM ACTIVITY. MORE ACTIVITY IS LIKELY IN
THE AFTERNOON AS A STRONGER UPPER LOW MOVES THROUGH. EXPECTING S TO
SE WINDS THROUGH THE PERIOD.
ELSEWHERE...A BROKEN LINE OF SHRA/TSTMS IS SLOWLY ADVANCING ACROSS
THE GA. CONDITIONS BECOME FAVORABLE FOR CONVECTION LATER
TONIGHT...THOUGH I/M NOT SURE IF THIS LINE WILL MAKE IT OR IF WE
WILL HAVE TO WAIT FOR MORE STORMS. AS A COMPROMISE...I HAVE TEMPO
THUNDER PROBS FROM 03-07. STRATUS IS A GOOD BET TONIGHT WITH MOIST
SOUTHEAST FLOW AND A LLVL WIND FIELD INCREASING TO AROUND 20 KTS.
WENT RIGHT ON THE CUSP OF IFR/MVFR. A LOT WILL DEPEND ON HOW MUCH
RAIN FALLS...BUT AS A RULE THAT MUCH LLVL WIND SHOULD KEEP US FROM
SEEING REALLY LOW CIGS. I DID GO LOWER AT KAVL. MORE SHRA/TSTMS ARE
EXPECTED TMRW. WINDS WILL BE S TO SE THROUGH THE PERIOD.
OUTLOOK...CONVECTION WILL DEVELOP AGAIN SUNDAY...BUT COVERAGE SHOULD
BE DIMINISHING. BRIEF DRYING IS POSSIBLE ON MON AND TUE WITH HIGH
PRES FOLLOWING FROPA.
CONFIDENCE TABLE...
01-07Z 07-13Z 13-19Z 19-01Z
KCLT HIGH 99% MED 74% MED 78% HIGH 100%
KGSP HIGH 100% MED 72% MED 78% HIGH 100%
KAVL LOW 54% HIGH 87% MED 63% MED 78%
KHKY HIGH 100% MED 75% MED 77% HIGH 100%
KGMU MED 77% MED 75% MED 74% HIGH 100%
KAND HIGH 99% HIGH 86% HIGH 85% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...VISIN
AVIATION...MCAVOY
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1252 PM CDT THU JUL 25 2013
.UPDATE...
UPDATED AVIATION DISCUSSION BELOW...
.PREVIOUS UPDATE DISCUSSION...
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AFTERNOON TAKING THE
SCATTERED SHOWERS/STORMS ALONG WITH MOST OF THE CLOUD COVER WITH
IT. VISIBLE SATELLITE AND RADAR SHOW THIS EASTWARD MOVEMENT/CLEARING
LATE THIS MORNING. WILL ADJUST GRIDS TO REFLECT THIS TREND.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS WILL BRING VFR
CONDS TO ALL TERMINALS THROUGH THE VALID FCST PERIOD. A WEAK
DISTURBANCE SLIDING QUICKLY THROUGH MAY BRING SOME SCT-BKN LOW
VFR /3K-4K FT/ CIGS TO THE KABR AND KATY TERMINALS BETWEEN 10Z AND
15Z FRIDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1119 AM MDT THU JUL 25 2013
.UPDATE...
ISSUED AT 846 AM MDT THU JUL 25 2013
LEFTOVER MCS EXITING CWA VIA SOUTH CENTRAL SD THIS MORNING.
SHORTWAVE ENERGY ASSOCIATED WITH MCS HEADING AWAY WITH SUBSIDENCE
BEHIND IT. LATEST RAP GUIDANCE SUGGESTS SOME INSTABILITY WILL
REDEVELOP BEHIND WAVE THIS AFTERNOON WITH MODEST MLCIN. SUBSIDENCE
WILL TEND TO SUPPRESS ORGANIZED ACTIVITY...BUT MOST CONVECTIVE
ALLOWING MODELS SUPPORT CURRENT FORECAST OF LOW POPS THIS
AFTERNOON/EARLY THIS EVENING. FORECAST UPDATED TO MATCH CURRENT
CONDITIONS/TIMING OF REDEVELOPMENT.
&&
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 344 AM MDT THU JUL 25 2013
NORTHERN STREAM SHORTWAVE TROUGH AND ASSOCIATED
CONVECTIVELY MODIFIED IMPULSE CONTINUES TO PROPAGATE SE ACROSS THE
AREA...SUPPORTING A DECENT CONVECTIVE COMPLEX ACROSS WESTERN SD. MCS
WILL CONTINUE TO PUSH SE ACROSS PORTIONS OF WESTERN SD...WITH
POSSIBLE ADDITIONAL BACKSIDE CONVECTION AS THE IMPULSE MOVES ACROSS
THE REGION AND THE PRIMARY LL TROUGH ADVECTS THROUGH THE FA...WITH A
CONTINUED POS THETA-E UPGLIDE REGIME. LL MOISTURE WILL INCREASE
BEHIND THIS INITIAL BOUNDARY...POSSIBLY SUPPORTING ADDITIONAL DIURNAL
SHRA/TS ACROSS THE SW HALF OF THE FA THIS AFTERNOON.
HOWEVER...CHANCES FOR PRECIP ARE EXPECTED TO WANE NORTH TO SOUTH
THROUGH THE DAY...AS BL MOISTURE BEGINS TO DEPLETE AND MID LEVEL
SUBSIDENCE COMMENCES ON THE BACKSIDE OF THIS MORNING/S WAVE. HAVE
ADJUSTED POPS/WX.
TEMPS WILL REMAIN TRICKY TODAY WITH A NOTED SIG SPREAD IN GUIDANCE
NUMBERS. HAVE SHIED FROM THE EXCESSIVELY WARM MAV...AND TRENDED
TOWARD THE MORE REASONABLE MET/ECMWF MOS NUMBERS...ESP GIVEN GFS
THERMAL FIELD BIAS. A STRONGER SECONDARY TROUGH WILL ADVECT THROUGH
ND AND INTO THE UPPER MIDWEST LATER TODAY INTO THIS
EVENING...SUPPORTING AN APPRECIABLE COLD FRONT INTO THE REGION
TONIGHT. THIS FRONT WILL COME THROUGH DRY...MAINLY SUPPORTING A
PERIOD OF POSSIBLE GUSTY N/NE WINDS.
SIG H85 TEMP ANOMALY WITH THIS TROUGH WILL SUPPORT TEMPS SOME 10 TO
15 DEGREES BELOW NORMAL FRIDAY...OVER THE EASTERN HALF OF THE
FA...WITH WARMER TEMPS RELEGATED TO THE FAR WEST. GIVEN PROGGED
ANOMALIES AND THERMAL FIELDS...HAVE CONTINUED THE TREND TO CUT
TEMPS FRIDAY...ESP ACROSS THE EAST WHERE SOME PLACES MAY STRUGGLE
TO BREAK 70. WEAK IMPULSE IN NW FLOW MAY SUPPORT AN ISOLD SHRA/TS
OVER NE WY AND THE BH LATE FRIDAY AFTERNOON...INTO SCENTRAL FRIDAY
NIGHT. MODELS CONTINUE TO INDICATE THIS SIGNAL AND HAVE RETAINED LOW
CHANCES POPS. COOL CONDITIONS WILL CONTINUE OVERNIGHT FRIDAY WITH
LOWS APPROACHING RECORD NUMBERS IN THE UPPER 40S OVER PORTIONS OF
WESTERN SD.
&&
.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 344 AM MDT THU JUL 25 2013
PERSISTENT UPPER LEVEL RIDGE OVER THE SOUTHWESTERN
CONUS AND A TROF TO THE EAST OF THE REGION WILL KEEP ACTIVE WEST TO
NORTHWEST FLOW OVER THE NORTHERN PLAINS THROUGH EARLY NEXT WEEK. A
SERIES OF UPPER LEVEL DISTURBANCES WILL PASS OVER THE REGION THROUGH
THE EXTENDED PERIOD...AND WILL BRING A DAILY CHANCE FOR RAIN SHOWERS
AND THUNDERSTORMS ACROSS MUCH OF THE AREA. TEMPERATURES WILL BE
SLIGHTLY BELOW AVERAGE ON SATURDAY...AND RISE TO NEAR AVERAGE
LEVELS FOR SUNDAY THROUGH EARLY NEXT WEEK.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON
ISSUED AT 1119 AM MDT THU JUL 25 2013
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT. HOWEVER...
LOCAL MVFR CIGS WILL LINGER AROUND THE BLACK HILLS AREA INTO THE
EARLY AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON AND EVENING ACROSS PORTIONS OF
NORTHEASTERN WY AND WESTERN SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...15
AVIATION...26
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1044 AM CDT THU JUL 25 2013
.UPDATE...
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AFTERNOON TAKING THE
SCATTERED SHOWERS/STORMS ALONG WITH MOST OF THE CLOUD COVER WITH
IT. VISIBLE SATELLITE AND RADAR SHOW THIS EASTWARD MOVEMENT/CLEARING
LATE THIS MORNING. WILL ADJUST GRIDS TO REFLECT THIS TREND.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA
DURING THE DAY. NO SEVERE WEATHER IS EXPECTED...BUT VSBYS MAY
BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE THUNDERSTORMS.
OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
623 AM CDT THU JUL 25 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA
DURING THE DAY. NO SEVERE WEATHER IS EXPECTED...BUT VSBYS MAY
BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE THUNDERSTORMS.
OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
342 AM CDT THU JUL 25 2013
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL FOR THE MOST PART OVERNIGHT AND
THROUGH THE DAY THURSDAY. SCATTERED SHOWERS AND THUNDERSTORMS MAY
PUSH INTO THE WESTERN CWA BY SUNRISE OR SO AND WILL REMAIN
POSSIBLE THROUGH THE DAYTIME HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
550 PM CDT THU JUL 25 2013
.UPDATE...
NORTHWARD MOVING OUTFLOW BOUNDARY FROM EARLIER CONVECTION LOOKS
LIKE IT WILL SPARK OFF A FEW STORMS IN THE METROPLEX THIS EVENING
WHERE AIRMASS IS UNCAPPED AND UNSTABLE. HAVE RECONFIGURED THE
SPATIAL ORIENTATION OF THE LOW POPS FOR THIS EVENING BASED ON
LATEST TRENDS. TR.92
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT THU JUL 25 2013/
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 20 40 30 10 5
WACO, TX 78 98 75 94 74 / 20 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 20 50 20 5 5
MCKINNEY, TX 76 89 69 91 70 / 20 50 30 10 5
DALLAS, TX 79 95 73 92 75 / 20 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 78 97 74 93 73 / 10 40 30 10 10
TEMPLE, TX 76 98 75 94 73 / 20 30 30 10 10
MINERAL WELLS, TX 76 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
350 PM CDT THU JUL 25 2013
.DISCUSSION...
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 10 40 30 10 5
WACO, TX 78 98 75 94 74 / 20 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 10 50 20 5 5
MCKINNEY, TX 76 89 69 91 70 / 10 50 30 10 5
DALLAS, TX 79 95 73 92 75 / 10 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 78 97 74 93 73 / 20 40 30 10 10
TEMPLE, TX 76 98 75 94 73 / 20 30 30 10 10
MINERAL WELLS, TX 76 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/82
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
120 PM CDT THU JUL 25 2013
.UPDATE...
SENT A QUICK UPDATE TO INCREASE POPS ACROSS THE PERMIAN BASIN
REGION FOR THE REST OF THE AFTERNOON. CU FIELD RAPIDLY DEVELOPING
OVER THE PERMIAN BASIN REGION OVER THE LAST HOUR...RAISING
CONCERNS FOR SHOWERS AND THUNDERSTORMS POPPING UP ACROSS THIS AREA
SHORTLY. SURFACE ANALYSIS SHOWS A WEAK CONVERGENT AREA NEAR THE
NORTHERN PERMIAN BASIN AND LATEST RUC INDICATES CONVECTION
DEVELOPING ALONG THIS BOUNDARY AROUND 19-20Z.
&&
.PREV DISCUSSION... /ISSUED 1218 PM CDT THU JUL 25 2013/
AVIATION...
18Z TAF ISSUANCE
CONVECTION HAS DIMINISHED OVER PORTIONS OF SOUTHEAST NEW MEXICO
THIS MORNING AND ALTHOUGH THERE IS A POSSIBILITY OF ADDITIONAL
DEVELOPMENT THIS AFTERNOON...CHANCES ARE TOO LOW ATTM TO INCLUDE
IN THE TAF. WILL AMEND IF LATER TRENDS SHOW ANY IMMINENT CHANGES.
OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS AT
ALL TAF SITES. GENERALLY SOUTH TO SOUTHEASTERLY WINDS AROUND 10KT
ARE SET TO PREVAIL THROUGH TODAY. A COLD FRONT WILL MOVE THROUGH
THE REGION DURING THE DAY FRIDAY AND WENT AHEAD AND SHIFTED WINDS
AT CNM/HOB/PEQ TO THE NORTH. WILL NEED TO MENTION THIS WIND SHIFT
AT THE OTHER SITES IN THE NEXT TAF ISSUANCE.
PREV DISCUSSION... /ISSUED 416 AM CDT THU JUL 25 2013/
DISCUSSION...
SCATTERED SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS THE TX
PANHANDLE AND SOUTHERN PARTS OF NEW MEXICO INCLUDING THE GUADALUPE
MOUNTAINS EARLY THIS MORNING. COULD SEE MORE SCATTERED SHOWERS AND
STORMS THIS AFTERNOON MAINLY ALONG AND NORTH OF I-20 AS A MID LEVEL
THETA E AXIS MOVES ACROSS THE AREA. TEMPERATURES WILL BE ABLE TO
CLIMB WELL INTO THE 90S AND LOWER 100S OVER MOST OF THE REGION
BEFORE CLOUDS THICKEN LATE IN THE AFTERNOON. RICH MOISTURE REMAINS
IN PLACE WITH PWATS NEAR 1.5" SO LOCALLY HEAVY RAIN IS POSSIBLE WITH
ANY STORM ONCE AGAIN TODAY.
A S/W MOVING ACROSS THE SOUTHERN PLAINS FRIDAY WILL BRIEFLY NUDGE
THE UPPER RIDGE WEST AND ALLOW A WEAK COLD FRONT TO BRUSH THE
REGION. THE FRONT IS STILL EXPECTED TO ARRIVE FRIDAY AROUND LUNCH
ACROSS THE PERMIAN BASIN PUSHING SOUTH AND WEST FRIDAY NIGHT.
FORCING AND LARGE SCALE LIFT WILL REMAIN WELL NE OF THE REGION SO
NOT MUCH IN THE WAY OF PRECIP IS EXPECTED WITH THE FRONT. ONE
EXCEPTION IS ACROSS LOCATIONS WEST OF THE PECOS RIVER BOTH LATE
FRIDAY AND SATURDAY AFTERNOON WHERE UPSLOPE FLOW WILL BE ENHANCED
BEHIND THE FRONT. SLIGHT COOLING BEHIND THE FRONT IS EXPECTED
SATURDAY WITH HIGHS DROPPING ABOUT 5 DEGREES FROM FRIDAY.
THE UPPER RIDGE BUILDS BACK ACROSS THE AREA BY SUNDAY AND STICKS
AROUND THROUGH MOST OF NEXT WEEK. HIGHS WILL CLIMB BACK INTO THE
UPPER 90S AND 100S OVER MOST OF THE REGION WITH THE USUAL AFTERNOON
STORM CHANCES CONFINED TO THE HIGHER TERRAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 73 96 69 91 / 20 20 10 10
BIG SPRING TX 75 97 69 91 / 20 20 10 10
CARLSBAD NM 70 98 71 92 / 20 20 20 20
DRYDEN TX 76 104 75 98 / 10 20 20 20
FORT STOCKTON TX 74 99 71 93 / 10 20 30 20
GUADALUPE PASS TX 67 88 65 84 / 20 20 20 20
HOBBS NM 71 90 67 88 / 20 20 10 10
MARFA TX 62 89 65 84 / 10 30 30 20
MIDLAND INTL AIRPORT TX 76 100 71 93 / 10 20 10 10
ODESSA TX 74 99 70 93 / 10 20 20 10
WINK TX 75 101 74 96 / 10 20 20 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
27/44
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
151 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT THURSDAY...
AFTERNOON UPDATE WILL REFLECT A SMALLER REGION ACROSS THE
MOUNTAINS THIS AFTERNOON THAT WILL HAVE THE POTENTIAL FOR SOME
ISOLATED SHOWERS AND STORMS. THE REGION OF INTEREST NOW IS
BOUNDED BY THE AREA THAT INCLUDES MARION VA TO BLACKSBURG VA TO
STUART VA TO YADKINVILLE NC TO BOONE NC. WITH A CONVECTIVE
TEMPERATURE AROUND 80 DEGREES...IT WILL BE FAIRLY LATE IN THE
AFTERNOON UNTIL CONVECTION FIRES. SCATTERED COVERAGE IS EXPECTED
ALONG THE CREST OF THE BLUE RIDGE WHERE OROGRAPHIC IMPACTS MAY
ALLOW FOR GREATER COVERAGE. HAVE MADE SOME MINOR ADJUSTMENTS UP
AND DOWN FOR EXPECTED HIGH TEMPERATURES THIS AFTERNOON. MOST OF
THE ADJUSTMENTS UPWARD WERE IN THE WEST WHERE TEMPERATURES WERE
NEARING THE PREVIOUSLY EXPECTED HIGHS...AND THERE WERE PLENTY OF
BREAKS IN THE CLOUD COVER. MOST OF THE ADJUSTMENTS DOWNWARD WERE
IN THE EAST WHERE SOME AREAS WERE STILL ALMOST 10 DEGREES SHY OF
FORECAST HIGHS AND CLOUD COVER WAS MORE ABUNDANT.
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM EDT THURSDAY...
PRIMARILY LOW END VFR SCATTERED LAYERS AND BROKEN CEILINGS ACROSS
THE REGION THIS AFTERNOON. NO SHOWERS OR STORMS HAVE DEVELOPED
YET...BUT ISOLATED COVERAGE IS EXPECTED ALONG AND NEAR A KBCB-KTNB
LINE BETWEEN ROUGHLY 19Z/3PM AND 01Z/9PM. THE REGION REMAINS NORTH
OF A COLD FRONT WITH NE-E WINDS ACROSS THE PIEDMONT...WITH LIGHT
AND VARIABLE TO CALM OVER THE MOUNTAINS. THROUGH THE OVERNIGHT
HOURS...DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION IN THE
WAKE OF THE COLD FRONT AND THE APPROACH OF HIGH PRESSURE. THERE
WILL REMAIN THE POTENTIAL FOR STRATO-CU REDEVELOPMENT DURING THE
OVERNIGHT ALONG AND EAST OF THE BLUE RIDGE AS WHAT REMAINING LOW
LEVEL MOISTURE POOLS ON THE LEE SIDE OF THE APPALACHIANS. THESE
CLOUDS WILL RANGE FROM MVFR TO LOW END VFR. PATCHY MOUNTAIN AND
RIVER VALLEY FOG IS ALSO POSSIBLE LATE TONIGHT INTO EARLY FRIDAY
MORNING. ANY SUB-VFR CONDITIONS WILL IMPROVE TO VFR BY 14Z/10AM
FRIDAY.
HEADING INTO THE WEEKEND...HIGH PRESSURE MOVES EAST OF THE REGION
AND AN UPPER TROUGH/SURFACE COLD FRONT APPROACHES FROM THE WEST.
THE RESULT WILL BE A RETURN OF MOIST...SOUTHERLY FLOW INTO THE
REGION AND THE DEVELOPMENT OF SHOWERS AND STORMS. THESE WILL BE
MAINLY OVER THE MOUNTAINS LATE FRIDAY AFTERNOON AND EVENING.
SATURDAY AND THROUGH SATURDAY NIGHT...COVERAGE WILL INCREASE
ACROSS THE ENTIRE REGION AS THE FRONT MOVES THROUGH THE REGION.
SOME OF THESE STORMS MAY BE ON THE STRONG SIDE. AREAS OF SUB-VFR
CEILINGS AND VISIBILITIES WILL ACCOMPANY THE HEAVIER SHOWERS AND
STORMS.
ON SUNDAY...THE FRONT WILL BE EAST OF THE AREA...HOWEVER...A WAVE
MOVING NORTH ALONG THE FRONT WILL HELP PROLONG THE CONVECTION AND
LOCALIZED SUB-VFR CONDITIONS OVER MAINLY EASTERN PARTS OF THE
AREA.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVER THE AREA.
THIS WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT
NIGHTTIME AND EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE
THANKS TO PLENTY OF BOUNDARY LAYER MOISTURE IN PLACE AFTER THE
RAIN OVER THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1256 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT THURSDAY...
AFTERNOON UPDATE WILL REFLECT A SMALLER REGION ACROSS THE
MOUNTAINS THIS AFTERNOON THAT WILL HAVE THE POTENTIAL FOR SOME
ISOLATED SHOWERS AND STORMS. THE REGION OF INTEREST NOW IS
BOUNDED BY THE AREA THAT INCLUDES MARION VA TO BLACKSBURG VA TO
STUART VA TO YADKINVILLE NC TO BOONE NC. WITH A CONVECTIVE
TEMPERATURE AROUND 80 DEGREES...IT WILL BE FAIRLY LATE IN THE
AFTERNOON UNTIL CONVECTION FIRES. SCATTERED COVERAGE IS EXPECTED
ALONG THE CREST OF THE BLUE RIDGE WHERE OROGRAPHIC IMPACTS MAY
ALLOW FOR GREATER COVERAGE. HAVE MADE SOME MINOR ADJUSTMENTS UP
AND DOWN FOR EXPECTED HIGH TEMPERATURES THIS AFTERNOON. MOST OF
THE ADJUSTMENTS UPWARD WERE IN THE WEST WHERE TEMPERATURES WERE
NEARING THE PREVIOUSLY EXPECTED HIGHS...AND THERE WERE PLENTY OF
BREAKS IN THE CLOUD COVER. MOST OF THE ADJUSTMENTS DOWNWARD WERE
IN THE EAST WHERE SOME AREAS WERE STILL ALMOST 10 DEGREES SHY OF
FORECAST HIGHS AND CLOUD COVER WAS MORE ABUNDANT.
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
954 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
709 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
127 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL HEAD SOUTH OF THE AREA OVERNIGHT...AND ITS
ASSOCIATED UPPER TROUGH WILL CROSS THE REGION ON THURSDAY. HIGH
PRESSURE WILL SETTLE OVER THE AREA BY FRIDAY...AND SHIFT EAST TO
THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE THROUGH THE
AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1130 PM EDT WEDNESDAY...
MODELS HAVE BEEN DOING PRETTY GOOD IN ADVERTISING CONVECTION OVER
THE PIEDMONT THIS EVENING AND STEERING IT WORD THE NC/VA BORDER.
WILL MAINTAIN CHANCE POPS...AS HIGH AS 50 ACROSS THE FAR SE THEN
TAPER TO SLIGHT FURTHER NW ACROSS THE FOOTHILLS OVERNIGHT.
PREVIOUS DISCUSSION...
AS OF 730 PM...
AN AXIS OF HIGHER INSTABILITY AND DECENT LOW LVL LAPSE RATES
EXISTS FROM WRN NC EAST INTO THE PIEDMONT OF NC/VA WITH SUBSIDENCE
AND DRIER AIR WORKING TOWARD SOUTHEAST WV. RADAR AT THE MOMENT
SHOWS CONVECTION SLOWLY TRUDGING EAST ACROSS THE BLUE RIDGE
MOUNTAINS AND FOOTHILLS NORTH OF LYNCHBURG VA...WITH ISOLATED
SHOWERS AND STORMS STARTING TO FADE FROM NE TN INTO THE FOOTHILLS
OF NORTH CAROLINA.
KEPT HIGHER POPS SITUATED ACROSS THE NORTHEAST PIEDMONT OF
BUCKINGHAM SOUTH TO SOUTHSIDE VA AND THEN WEST TOWARD WILKES
COUNTY NC THIS EVENING WITH DRIER WX IN THE NORTHWEST.
18Z NAM/GFS...12Z ECMWF AND THE LATEST HRRR SHOWING OVERALL
AGREEMENT IN BRING A CLUSTER OF SHOWERS/STORMS ACROSS THE
SOUTHEAST CWA AROUND 03Z AS THE UPPER SHORTWAVE MOVES EAST OF OUT
TN. BUMPED POPS UP SOME HERE AND MAY NEED TO GO EVEN HIGHER IF
THIS HAPPENS. BIG CONSIDERATION IS INSTABILITY WEAKENING AS SUN
SETS BUT GIVEN HOW WARM IT IS OUT THERE NOW AND ADDING SOME UPPER
LIFT...THINKING IS CONVECTION SHOULD MAINTAIN ITSELF ACROSS THE
NORTH CAROLINA FOOTHILLS PIEDMONT AND NWD TOWARD SOUTHSIDE VA INTO
THE OVERNIGHT HOURS...WITH THE LIGHTNING SIDE OF THINGS SUBSIDING
OVERNIGHT.
PREVIOUS VALID DISCUSSION...
THE FRONT IS EXPECTED TO HAVE MOVED SOUTH THROUGH MOST...IF NOT
ALL...OF THE REGION BY MIDNIGHT. BEHIND THE FRONT...SURFACE AND
LOW LEVELS WINDS ARE PROGGED TO VEER NORTHEAST TO ALMOST EAST IN
SOME AREAS. THIS WILL HAVE THE IMPACT OF KEEPING LINGERING
MOISTURE IN THE BOUNDARY LAYER PINNED UP AGAINST THE CREST OF THE
BLUE RIDGE. WE ARE EXPECTING STRATUS CLOUDS TO DEVELOP OVERNIGHT
AND LOWER AS THE NIGHT PROGRESSES. THIS MAY ALSO HELP YIELD SOME
DRIZZLE IN THE CREST OF THE BLUE RIDGE. PATCHY OR AREAS OF FOG ARE
ALSO EXPECTED ALONG AND NEAR THE PORTION OF THE BLUE RIDGE
SOUTHWEST OF ROANOKE. THE PROXIMITY OF THE FRONT WILL ALSO HELP
MAINTAIN SOME SHOWERS ACROSS THE SOUTHEAST PART OF THE REGION. LOW
TEMPERATURES TONIGHT WILL BE AROUND 5 TO 8 DEGREES COOLER THAN
TEMPERATURES REALIZED THIS MORNING THANKS TO LOWERING DEW POINTS
BEHIND THE FRONT.
ON THURSDAY...CLOUD COVER WILL BE SLOW TO ERODE...ESPECIALLY ALONG
AND EAST OF THE BLUE RIDGE SOUTHWEST OF ROANOKE. THIS REGION WILL BE
CLOSEST TO THE DEPARTING COLD FRONT AS IT DEVELOPS A SMALL BUCKLE IN
IT WITH THE PASSAGE OF THE PARENT UPPER TROUGH. ALSO...SURFACE
AND LOW LEVEL WINDS WILL HAVE A GREATER EASTERLY COMPONENT. THIS
POINTS TOWARDS THE AREA KEEPING THE CLOUDS LONGER WITH ISOLATED TO
SCATTERED SHOWERS AND A FEW STORMS. HIGHS TOMORROW WILL BE SIMILAR
OR ONLY SLIGHTLY COOLER THAN TEMPERATURES OF TODAY ACROSS THE
MOUNTAINS. OVER THE PIEDMONT...HIGHS WILL BE AROUND 10 DEGREES
COOLER THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
THE SHORT TERM WILL BE DOMINATED BY A BROAD EASTERN U.S.
TROUGH...CONTINUALLY REINFORCED BY UPSTREAM SHORT WAVES. AT THE
BEGINNING OF THE SHORT TERM...THE TROUGH AXIS ATTEMPTS TO SHIFT EAST
OF THE AREA AS A COASTAL LOW MOVES UP AND JUST OFF THE MID-ATLANTIC
COAST. HOWEVER...A STRONG UPSTREAM SHORT WAVE MOVING SOUTHEAST OUT
OF ALBERTA...WILL SHIFT THE TROUGH AXIS BACK INTO THE OHIO VALLEY BY
SATURDAY. WITH SUBSIDENCE EXPECTED BEHIND THE DEPARTING COASTAL LOW
AND NOTABLY DRY AIR...DEW POINTS IN THE 50S/LOW 60S...ADVECTING INTO
THE NW HALF OF THE CWA...HAVE CONFINED SLIGHT CHC POPS TO THE FAR
SOUTHEAST AND POTENTIAL EASTERLY FLOW UPSLOPE AREAS IN THE NW NC
MOUNTAINS AT THE BEGINNING. UPSLOPE EASTERLY FLOW WILL INCREASE
SATURDAY ALONG THE ALLEGHANYS AND BLUE RIDGE OF NW NC...SO HAVE
CONTINUED TO INCREASE POPS IN THE WESTERN AREAS AS A RESULT FOR FRI
AFTERNOON. BY SATURDAY...OUR ATTENTION TURNS TO THE UPSTREAM DIGGING
TROUGH...WHICH SHOULD BE THE NEXT WIDESPREAD PCPN EVENT FOR OUR CWA.
TOO FAR OUT TO BE CONCERNED ABOUT RAINFALL AMOUNTS...BUT THIS WOULD
BE THE NEXT TIME FRAME FOR ANY SIGNIFICANT SEVERE OR FLASH FLOOD
THREAT. HAVE GONE AHEAD AND ADVERTISED LIKELY POPS FOR SAT
AFTERNOON/EVENING IN THE WEST.
SOMEWHAT COOLER MIN TEMPS WILL BE NOTED AT THE
BEGINNING...ESPECIALLY IN THE WEST WITH DEWPOINTS DROPPING INTO THE
50S ACROSS THE ALLEGHANYS. LOWS SHOULD BE IN THE MID TO UPPER 50S IN
THE HIGHER ELEVATIONS ACROSS SW VA/NW NC/SE WV. BY SATURDAY...WITH
SW FLOW RETURNING AND INCREASING MOISTURE...MIN TEMPERATURES WILL
CREEP CLOSER TO NORMAL. MAX TEMPS SHOULD AVERAGE JUST BELOW NORMAL
THROUGH THE PERIOD. OVERALL...CONTINUED BELOW NORMAL AS MOST OF THIS
SUMMER HAS BEEN SO FAR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AS OF 120 AM EDT THURSDAY...
CONVECTION CONTINUES TO PERSIST ALONG AND SE OF THE BLUE RIDGE
ATTM AND EXPECT COVERAGE TO CONSOLIDATE A BIT SOUTH/SW OF KDAN IN
THE NEXT HOUR OR TWO BEFORE CELLS FINALLY WEAKEN. ALSO SEEING A
FEW SHRA FARTHER NORTH NEAR KROA SO WILL BE INCLUDING A VCSH
MENTION THERE TO KLYH AND PERHAPS PREVAILING -SHRA AROUND KDAN
OVERNIGHT. OTRW DEWPOINT FRONT REMAINS STUCK JUST EAST OF THE BLUE
RIDGE WITH LOW LEVEL NE FLOW AIDING CONVERGENCE WHICH HAS ALSO
SHIFTED LOWER CLOUDS WEST INTO SE WVA. THUS THINKING WILL SEE AT
LEAST MVFR CIGS OUT EAST THROUGH DAYBREAK THU WITH PERIODS OF IFR
ONCE SHRA FADE SOME AND STRATUS DEVELOPS. ALSO MAY SEE BASES LOWER
TO MVFR LEVELS BACK TO KBCB AND POSSIBLY INTO KBLF AND KLWB WHERE
MORE FOG AND MVFR/IFR VSBYS LIKELYS AS WELL.
FOR THURSDAY...THE FLOW REMAINS OUT OF THE NORTHEAST TO AT TIME
EAST...SO CIGS MAY LINGER THROUGH THIS PERIOD...WITH VFR EXPECTED
AFTER 15-17Z. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH OF ROANOKE BUT CANNOT RULE OUT KBCB/KROA AND MAYBE EVEN KBLF
SEEING SHOWERS OR STORMS NEARBY.
THURSDAY EVENING...THE AXIS OF THE UPPER TROUGH PASSES OVERHEAD.
EVEN THOUGH DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN
ISSUE AT BCB/LWB GIVEN WET SOILS AND LIGHT WIND.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
608 PM CDT FRI JUL 26 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 349 PM CDT FRI JUL 26 2013
AT 3 PM...A SURFACE LOW WAS LOCATED OVER NORTHEAST WISCONSIN. A
COLD FRONT EXTENDED SOUTHWEST FROM THIS LOW THROUGH THE WISCONSIN
DELLS AND THE EASTERN PORTIONS OF GRANT COUNTY. SCATTERED SHOWERS
AND THUNDERSTORMS WERE FOUND AHEAD OF THIS FRONT. A SECONDARY COLD
FRONT FROM MEDFORD WISCONSIN TO WOOD LAKE MINNESOTA. ALONG AND
BEHIND THIS FRONT...THERE WERE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS.
FOR TONIGHT...THE 26.12Z MODELS ARE IN GOOD AGREEMENT THAT THE
900 TO 700 MB LAYER WILL REMAIN FAIRLY SATURATED ACROSS WISCONSIN
OVERNIGHT. AS A RESULT KEPT SKIES MAINLY BROKEN. MEANWHILE IN
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...IT IS LESS CLEAR SO WENT
WITH A SCATTERED TO BROKEN DECK OF CLOUDS IN THESE AREAS. WITH THE
MODELS SHOWING THAT THE ML CAPES QUICKLY DISSIPATING THIS
EVENING...JUST WENT WITH EVENING SHOWERS ALONG AND NORTH OF
INTERSTATE 94.
ON SATURDAY...THE MODELS SHOW THAT 850 MB TEMPERATURES WILL ONLY
RANGE FROM 3 TO 6C ACROSS WESTERN WISCONSIN AND 6 TO 8C IN
NORTHEAST IOWA AND SOUTHEAST MINNESOTA. THESE TEMPERATURES ARE 2
TO 3 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR...SO
EXPECTING RECORD OR NEAR RECORD MAXIMUM TEMPERATURES RANGING FROM
THE UPPER 50S TO MID 60S. NORMAL HIGH TEMPERATURES ARE IN THE
LOWER AND MID 80S. WITH 950 MB TO 800 MB LAPSE RATES OF 8 TO
10C/KM AND ML CAPES UP TO 100 J/KG...EXPECT ISOLATED TO SCATTERED
SHOWERS TO DEVELOP BY MID MORNING AND THEN CONTINUE INTO THE
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 349 PM CDT FRI JUL 26 2013
ON SATURDAY NIGHT...THE MODELS SHOW THAT A STRONG VORTICITY
MAXIMUM WILL MOVE SOUTHEAST ACROSS WISCONSIN. WITH GOOD 950 TO
650 MB...EXPECT THAT THE ISOLATED TO SCATTERED SHOWERS WILL
CONTINUE ACROSS WESTERN WISCONSIN. THE HIGHEST PRECIPITATION
CHANCES WILL EB FOUND NORTH OF THE INTERSTATE 94 CORRIDOR. THIS
VORT MAX WILL BE ACCOMPANIED WITH 2C 850 MB TEMPERATURES. THIS IS
2.5 TO 3 STANDARD DEVIATIONS BELOW NORMAL. FORTUNATELY IT LOOKS
LIKE THERE BE MAINLY MOSTLY CLOUDY SKIES ACROSS THE AREA OR WE
COULD BE POTENTIALLY LOOKING AT LOW TEMPERATURES FALLING TO AROUND
40 DEGREES. DUE TO THE CLOUDS...THESE TEMPERATURES WILL LIKELY
RANGE FROM THE MID 40S TO LOWER 50S.
ON SUNDAY...THE CLOSED 500 MB LOW OVER LAKE SUPERIOR WILL KEEP
UNUSUALLY 850 MB TEMPERATURES ACROSS THE REGION. 850 MB
TEMPERATURE ANOMALIES WILL RANGE FROM 2 TO 2.5 STANDARD DEVIATIONS
BELOW NORMAL. SINCE THE MOS TEMPERATURES TAKE IN CLIMATOLOGY...
STAYED AWAY FROM ANY BLEND THAT CONTAINED THEM AND WENT MORE WITH
A BLEND OF THE ACTUAL MODEL TEMPERATURES TO CAPTURE BETTER THE
UNUSUALLY COOL TEMPERATURES ACROSS THE REGION. LIKE SATURDAY...
THE 950 TO 800 MB LAPSE RATES WILL RANGE FROM 8 TO 10 C/KM AND ML
CAPES WILL CLIMB UP TO 100 J/KG ACROSS WESTERN WISCONSIN. DUE TO
THIS KEPT A MENTION OF ISOLATED TO SCATTERED SHOWERS.
ON MONDAY AND MONDAY NIGHT...THE MODELS ARE SHOWING 500 MB RIDGING
WILL DEVELOP IN THE WAKE OF THE CLOSED 500 MB LOW ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THIS WILL KEEP THE FRONTOGENESIS AND
BEST 850 MB MOISTURE TRANSPORT WELL TO OUR SOUTHWEST. WITH THE
EXCEPTION OF THE GEM...THE REMAINDER OF THE MODELS HAVE THE AREA
DRY FOR THIS TIME PERIOD. THIS MAKES A LOT SENSE WHEN CONSIDERING
THE DRY DEW POINTS ACROSS THE REGION...THUS...TOOK THE
PRECIPITATION CHANCES OUT OF THE FORECAST. IN ADDITION WITH THE
850 MB TEMPERATURES RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL...STAYED AWAY FROM ANY BLEND WHICH CONTAINED THE MOS TO
BETTER REPRESENT THE COOLNESS RESIDING ACROSS THE REGION.
ON WEDNESDAY NIGHT...BOTH THE GFS AND ECMWF ARE IN AGREEMENT THAT
THERE WILL BE STRONG SUBSIDENCE ACROSS THE REGION IN THE WAKE OF
COLD FRONT FRONT. DUE TO THIS...REMOVED THE LOW PRECIPITATION
CHANCES THAT WERE IN THE ALL BLEND DATA BASE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 608 PM CDT FRI JUL 26 2013
CYCLONIC FLOW IN PLACE ACROSS THE AREA AROUND AN ELONGATED AREA OF
SURFACE LOW PRESSURE THAT EXTENDS FROM EASTERN WISCONSIN TO EASTERN
LAKE SUPERIOR. SATELLITE SHOWING CONSIDERABLE CLOUDINESS IN THIS
CYCLONIC FLOW FROM NORTHWEST WISCONSIN AND EASTERN MINNESOTA INTO
ONTARIO. BOTH THE 26.18Z NAM AND 26.21Z RAP INDICATE THE MOISTURE
FIELD WITH THESE CLOUDS WILL SPREAD ACROSS THE AREA TONIGHT AND
REMAIN THROUGH SATURDAY. WHILE THE EXPECTATION IS THAT SOME OF THE
CURRENT CLOUDS WILL DISSIPATE WITH SUNSET...THE MORE SOLID AREA OF
CLOUDS WILL MOVE IN DURING THE EVENING. CEILINGS WILL COME DOWN
BUT SHOULD REMAIN VFR...ALTHOUGH IF ENOUGH COOLING TAKES PLACE THE
CEILINGS COULD GO DOWN TO MVFR. ANY SHOWERS THAT DEVELOP SATURDAY
IN THE CYCLONIC FLOW ARE EXPECTED TO REMAIN NORTHEAST OF BOTH TAF
SITES AND WILL NOT INCLUDE A VCSH FOR EITHER SITE.
&&
.CLIMATE...WEEKEND
ISSUED AT 349 PM CDT FRI JUL 26 2013
THROUGH THE WEEKEND...THERE WILL BE POSSIBILITY FOR RECORD COLD
MAXIMUMS AND COLD MINIMUMS. HERE ARE SOME OF THE RECORDS FOR
TONIGHT AND SATURDAY.
RECORD LOW TEMPERATURES FOR TONIGHT...
AUSTIN MN 47 IN 1980
ROCHESTER MN 47 IN 1920
CHARLES CITY IA 47 IN 1971
DECORAH IA 46 IN 1962
MEDFORD WI 42 IN 1893
LA CROSSE WI 48 IN 1891
PRAIRIE DU CHIEN 45 IN 1911
SPARTA WI 42 IN 1971
RECORD LOW MAXIMUM TEMPERATURES FOR SATURDAY...
AUSTIN MN 67 IN 2005
ROCHESTER MN 64 IN 1981
CHARLES CITY IA 65 IN 1905
DECORAH IA 65 IN 1972
MEDFORD WI 62 IN 1945
LA CROSSE WI 69 IN 1981
PRAIRIE DU CHIEN 67 IN 1972
SPARTA WI 71 IN 2005
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
CLIMATE...BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
526 PM CDT THU JUL 25 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 525 PM CDT THU JUL 25 2013
SHOWERS AND STORMS WILL BE ON THE INCREASE TONIGHT AS
A LOW PRESSURE DEVELOPS AND DEEPENS OVER NORTHERN WISCONSIN BY
FRIDAY MORNING. SHOWERS AND STORMS EXPECTED TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS LATE TONIGHT INTO FRIDAY MORNING ALONG WITH
SCATTERED AREAS OF IFR CIGS FRIDAY MORNING. A LITTLE DRIER AIR ON
NORTHWEST WINDS WORKING INTO PARTS OF CENTRAL AND EAST CENTRAL
WISCONSIN LATER FRIDAY MAY RAISE CIGS TO VFR LEVELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1236 PM CDT THU JUL 25 2013
AN AREA OF LOW PRESSURE WILL SLOWLY CURL FROM NORTHERN
MINNESOTA TO NORTHEAST WISCONSIN OVER THE TAF PERIOD. CLOUDS ALONG
WITH SHOWERS AND STORMS WILL BE BUILDING DURING THE
AFTERNOON...MAINLY WEST OF THE FOX VALLEY AND BAY OF GREEN BAY.
COVERAGE WILL LIKELY BE SCATTERED BUT DECENT ENOUGH TO IMPACT THE
CENTRAL WISCONSIN AND RHI TAF SITES. TIMING OF PRECIP THEREAFTER IS
RATHER DIFFICULT. BUT EARLY INDICATIONS ARE THAT THERE WILL BE A
LULL IN THE PRECIPITATION UNTIL LATE IN THE EVENING AND OVERNIGHT WHEN THE
LOW PRESSURE AND ATTENDANT COLD FRONT SLOWLY MOVE SOUTHEAST ACROSS
THE STATE. SEVERAL HOURS OF SHOWERS AND THUNDERSTORMS APPEARS LIKELY
AHEAD OF THE FRONT. BEHIND THE FRONT...WINDS WILL SHIFT TO THE
NORTHWEST AND USHER IN A MVFR OVERCAST WITH OCCASIONAL SHOWER
ACTIVITY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
647 AM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 647 AM CDT THU JUL 25 2013
SHOWERS AND A FEW THUNDERSTORMS HAVE DROPPED INTO PORTIONS OF
SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN EARLY THIS
MORNING...AHEAD OF A SHORTWAVE THAT AS OF 11Z WAS LOCATED NEAR
MINNEAPOLIS. THESE SHOWERS AND STORMS SHOULD CONTINUE MARCHING
SOUTHEAST THROUGH MUCH OF THE FORECAST AREA...AIDED BY A ZONE OF
850MB MOISTURE TRANSPORT AHEAD OF THE SHORTWAVE.
DURING THE AFTERNOON AND EVENING...MESOSCALE MODEL GUIDANCE FROM
THE LAST FEW HRRR RUNS...THE 25.00Z HIRES-ARW/HIRES-NMM/NSSL WRF-
ARW ARE ALL IN PRETTY GOOD AGREEMENT IGNITING CONVECTION AS EARLY
AS 19-20Z ACROSS SOUTHERN MN AND NORTHERN IOWA. APPEARS TWO
FORCING MECHANISM COME INTO PLAY:
1. 850MB MOISTURE TRANSPORT AHEAD OF A CONVECTIVE SHORTWAVE
EMANATING OUT OF THE STORMS CURRENTLY IN WESTERN SOUTH DAKOTA.
2. THE COLD FRONT CURRENTLY ALONG THE DAKOTAS/MN BORDER.
THE QUESTION BECOMES DO THE STORMS GET OUT OF HERE QUICKER THAN
FORECAST WHICH THE AFOREMENTIONED MESOSCALE MODELS SUGGEST. GOING
FOR THE QUICKER EXIT OF STORMS WOULD BE THE COOLING OUTFLOWS FROM
THE STORMS STABILIZING THE ATMOSPHERE...AND POSSIBLY PUSHING THE
COLD FRONT THROUGH FASTER. HOWEVER...THEN THERE IS THE 25.00Z
ECMWF/REGIONAL CANADIAN MODELS WHICH SEEM TO PUT MORE FOCUS ON
CONVECTIVE ACTIVITY IN THE EVENING. THESE MODELS RELY ON A
STRONGER INCREASE OF 850MB MOISTURE TRANSPORT AHEAD OF THE
SHORTWAVE TROUGH DROPPING OUT OF SOUTHERN MANITOBA INTO NORTHERN
MN. FOR NOW HAVE TRENDED THE TONIGHT FORECAST TO BE A COMPROMISE
APPROACH BETWEEN THE ECMWF AND HI RESOLUTION MODEL
GUIDANCE...LOWERING CHANCES A LITTLE BIT OVER NORTHWESTERN
PORTIONS OF THE FORECAST AREA FOR THE EVENING. THE SPEED THAT
CONVECTION GETS OUT OF HERE WILL HAVE TO BE LOOKED AT MORE THROUGH
THE DAY.
SEVERE POTENTIAL REMAINS...WITH 25.09Z HRRR SUGGESTING AN ISOLATED
SEVERE STORM OR TWO POSSIBLE. TIME PERIOD OF SEVERE POTENTIAL ON
TRACK...BETWEEN 3 AND 8 PM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
TODAY WITH THE POTENTIAL FOR STRONG TO SEVERE STORMS. FOCUS THEN
TURNS TO SHOWER AND STORM CHANCES FRIDAY...THEN ONTO TEMPERATURES
FOR THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST
FLOW ALOFT ACROSS THE UPPER MIDWEST. SEVERAL EMBEDDED SHORTWAVES
NOTED IN THE THE FLOW WITH A LEADING WEAK WAVE OVER SOUTH CENTRAL
MINNESOTA AND ANOTHER WAVE MOVING INTO NORTHWEST SOUTH DAKOTA. A
POTENT TROUGH WAS DIGGING INTO SOUTHERN SASKATCHEWAN/MANITOBA. THIS
TROUGH WILL BRING FALL-LIKE TEMPERATURES TO THE REGION FOR THE
WEEKEND. SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM
NORTH CENTRAL MINNESOTA SOUTHWEST ACROSS SOUTHERN NORTH DAKOTA AND
WAS PUSHING SOUTHEAST. A PREFRONTAL TROUGH WAS NOTED AS WELL
STRETCHING FROM NORTHEAST MINNESOTA SOUTH THROUGH CENTRAL MINNESOTA
INTO EASTERN SOUTH DAKOTA.THE TROUGH AND COLD FRONT WILL BE THE
FOCUS FOR SHOWER AND STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
AFTERNOON HOURS AND INTO THIS EVENING.
ISOLATED SHOWERS AND STORMS WILL JUST EDGE INTO SOUTHEAST MINNESOTA
AND WEST CENTRAL WISCONSIN THIS MORNING AS WEAK 850 MB MOISTURE
TRANSPORT MOVES INTO THE AREA. THIS ACTIVITY SHOULD WEAKEN AS IT
SLIDES SOUTHEAST THIS MORNING. ADDITIONAL DEVELOPMENT IS EXPECTED BY
LATE MORNING ALONG THE PREFRONTAL TROUGH LATE THIS MORNING INTO THE
EARLY AFTERNOON HOURS. MID AND HIGH LEVEL CLOUDS WORKING INTO THE
AREA FROM THE WEST WILL HAVE AN IMPACT ON HOW MUCH SURFACE
TEMPERATURES WARM TODAY. DEPENDING ON HOW MUCH WARMING
OCCURS...SEVERE THUNDERSTORMS ARE POSSIBLE MAINLY IN THE 3 TO 8 PM
TIMEFRAME. 0-6 KM BULK SHEAR VALUES INCREASE FROM AROUND 25 KTS
LATE THIS MORNING TO 35 TO 40 KTS LATE AFTERNOON INTO THE EVENING
HOURS. THE NAM CONTINUES TO BUILD STRONG INSTABILITY THIS
AFTERNOON WITH 0-3 KM MUCAPE VALUES CLIMBING TO AROUND 3000 J/KG.
THIS WOULD BE IF DEWPOINTS WOULD CLIMB INTO THE UPPER 60S TO LOWER
70S AND SURFACE TEMPERATURES WARM INTO THE LOWER 80S. SURFACE
TEMPERATURES ARE FORECAST TO CLIMB INTO THE UPPER 70S TO THE LOWER
80S BUT DEWPOINTS WILL BE MUCH LESS...IN THE 62 TO 65 DEGREE
RANGE. THINKING 0-3KM MUCAPE VALUES IN THE 1200 TO 1700 J/KG RANGE
SEEM MORE REALISTIC. THE POTENTIAL EXIST FOR A FEW ROUNDS OF
SHOWERS AND STORMS ALONG THE PREFRONTAL TROUGH AND ANOTHER TONIGHT
AS THE UPPER TROUGH DIVES SOUTHEAST INTO THE REGION AND THE COLD
FRONT EDGES CLOSER TO THE FORECAST AREA. IF STORMS HOLD OFF UNTIL
MID TO LATE AFTERNOON...LARGE HAIL AND DAMAGING WINDS MAY OCCUR
WITH THE STRONGER STORMS. THE FRONT IS EXPECTED TO PUSH THROUGH
THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY MORNING TAKING
THE BULK OF THE INSTABILITY SOUTH OF THE AREA. HOWEVER...THE
TROUGH WILL MOVE IN ITS WAKE WITH SHOWER AND ISOLATED STORM
CHANCES PERSISTING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 357 AM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS WILL BE ONGOING FRIDAY MORNING...ESPECIALLY
ACROSS CENTRAL AND FAR SOUTHWEST WISCONSIN. THE UPPER LEVEL TROUGH
THEN DIVES INTO THE AREA LATE FRIDAY MORNING INTO FRIDAY AFTERNOON.
SCATTERED TO NUMEROUS SHOWERS WILL DEVELOP AS COLDER AIR ALOFT MOVES
INTO THE AREA. THE TROUGH WILL REMAIN OVER THE REGION FRIDAY NIGHT
INTO SATURDAY AS AN UNSEASONABLY COLD AIRMASS MOVES IN. 850 MB
TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE -2.0 TO -2.5
RANGE...SUGGESTING NEAR RECORD COOL TEMPERATURES FOR THIS TIME OF
YEAR. HIGH TEMPERATURES ON SATURDAY WILL STRUGGLE TO GET OUT OF THE
60S. IN FACT...IT APPEARS LA CROSSE MAY SEE A RECORD LOWEST HIGH
TEMPERATURE FOR THE DATE. LATEST FORECAST IS 68 DEGREES AT LA
CROSSE. THIS WOULD BREAK THE OLD RECORD OF 69 SET BACK IN 1981.
FORECAST MODELS SUGGEST THERE WILL BE ENOUGH INSTABILITY ON SATURDAY
AFTERNOON TO GENERATE SOME SHOWERS...MAINLY ALONG AND NORTH OF
INTERSTATE 94. THIS MAKES SENSE LOOKING AT FORECAST SOUNDINGS
SHOWING SOME WEAK CAPE DURING THE AFTERNOON HOURS. HAVE ADDED A
SLIGHT CHANCE OF SHOWERS OVER CENTRAL WISCONSIN TO ACCOUNT FOR THIS.
ANOTHER SHORTWAVE ROTATES INTO NORTHERN WISCONSIN SATURDAY
NIGHT...BRINGING ADDITIONAL CHANCES FOR SHOWERS OVER NORTH CENTRAL
WISCONSIN. FLOW ALOFT THEN FINALLY STARTS TO TRANSITION TO ZONAL
EARLY NEXT WEEK AS THE TROUGH PUSHES EAST OF THE REGION INTO THE
EASTERN GREAT LAKES. TEMPERATURES WILL RETURN TO MORE SEASONABLE
VALUES FOR NEXT WEEK WITH HIGH CLIMBING BACK INTO THE UPPER 70S TO
AROUND 80. SEVERAL EMBEDDED WAVES IN THE ZONAL FLOW WILL BRINGING
PERIODIC CHANCES FOR SHOWERS AND STORMS MAINLY MONDAY NIGHT
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 647 AM CDT THU JUL 25 2013
A BAND OF SHOWERS AND EVEN A COUPLE THUNDERSTORMS WERE APPROACHING
BOTH TAF SITES AS OF 11Z. THESE SHOULD MOVE THROUGH THE TAF SITES
RELATIVELY QUICKLY...BY 14Z. NO VISIBILITY RESTRICTION IS
ANTICIPATED WITH CEILINGS STAYING VFR. THE VFR CONDITIONS LOOK TO
PERSIST THROUGH EARLY AFTERNOON. A COLD FRONT THEN LOOKS TO
APPROACH THE TAF SITES OUT OF WESTERN MINNESOTA. NUMEROUS SHOWERS
AND THUNDERSTORMS WILL FORM AHEAD OF THIS FRONT...BEING IN THE
VICINITY OF THE TAF SITES PERHAPS AS EARLY AS 17-18Z. CONFIDENCE
HAS INCREASED ENOUGH TO INCLUDE A TIME PERIOD WHERE THUNDERSTORMS
COULD DIRECTLY IMPACT THE TAF SITES...WHICH IS 19-22Z AT RST AND
20-23Z AT LSE. RESTRICTION TO MVFR VISIBILITIES AND CEILINGS IS
LIKELY...AND VISIBILITY COULD EVEN GO LOWER BRIEFLY. ADDITIONALLY
THERE COULD BE GUSTY WINDS AND HAIL...BUT CONFIDENCE IS TOO LOW TO
INCLUDE RIGHT NOW. SHOWERS AND THUNDERSTORMS MAY BE DONE WITH AT
BOTH TAF SITES BY 00Z...BUT NOT ALL MODEL GUIDANCE SUGGESTS SO.
THEREFORE...HAVE HELD ONTO VCTS MENTION TIL 03-04Z. VFR CONDITIONS
ARE EXPECTED TO PERSIST THROUGH THE NIGHTTIME HOURS IN THE WAKE OF
THE COLD FRONTAL PASSAGE. IF THE TAF SITES DO SEE RAIN...THERE
SHOULD BE ENOUGH ALTOSTRATUS AROUND DURING THE NIGHT TO PREVENT
FOG FORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
357 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
TODAY WITH THE POTENTIAL FOR STRONG TO SEVERE STORMS. FOCUS THEN
TURNS TO SHOWER AND STORM CHANCES FRIDAY...THEN ONTO TEMPERATURES
FOR THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST
FLOW ALOFT ACROSS THE UPPER MIDWEST. SEVERAL EMBEDDED SHORTWAVES
NOTED IN THE THE FLOW WITH A LEADING WEAK WAVE OVER SOUTH CENTRAL
MINNESOTA AND ANOTHER WAVE MOVING INTO NORTHWEST SOUTH DAKOTA. A
POTENT TROUGH WAS DIGGING INTO SOUTHERN SASKATCHEWAN/MANITOBA. THIS
TROUGH WILL BRING FALL-LIKE TEMPERATURES TO THE REGION FOR THE
WEEKEND. SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM
NORTH CENTRAL MINNESOTA SOUTHWEST ACROSS SOUTHERN NORTH DAKOTA AND
WAS PUSHING SOUTHEAST. A PREFRONTAL TROUGH WAS NOTED AS WELL
STRETCHING FROM NORTHEAST MINNESOTA SOUTH THROUGH CENTRAL MINNESOTA
INTO EASTERN SOUTH DAKOTA.THE TROUGH AND COLD FRONT WILL BE THE
FOCUS FOR SHOWER AND STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
AFTERNOON HOURS AND INTO THIS EVENING.
ISOLATED SHOWERS AND STORMS WILL JUST EDGE INTO SOUTHEAST MINNESOTA
AND WEST CENTRAL WISCONSIN THIS MORNING AS WEAK 850 MB MOISTURE
TRANSPORT MOVES INTO THE AREA. THIS ACTIVITY SHOULD WEAKEN AS IT
SLIDES SOUTHEAST THIS MORNING. ADDITIONAL DEVELOPMENT IS EXPECTED BY
LATE MORNING ALONG THE PREFRONTAL TROUGH LATE THIS MORNING INTO THE
EARLY AFTERNOON HOURS. MID AND HIGH LEVEL CLOUDS WORKING INTO THE
AREA FROM THE WEST WILL HAVE AN IMPACT ON HOW MUCH SURFACE
TEMPERATURES WARM TODAY. DEPENDING ON HOW MUCH WARMING
OCCURS...SEVERE THUNDERSTORMS ARE POSSIBLE MAINLY IN THE 3 TO 8 PM
TIMEFRAME. 0-6 KM BULK SHEAR VALUES INCREASE FROM AROUND 25 KTS
LATE THIS MORNING TO 35 TO 40 KTS LATE AFTERNOON INTO THE EVENING
HOURS. THE NAM CONTINUES TO BUILD STRONG INSTABILITY THIS
AFTERNOON WITH 0-3 KM MUCAPE VALUES CLIMBING TO AROUND 3000 J/KG.
THIS WOULD BE IF DEWPOINTS WOULD CLIMB INTO THE UPPER 60S TO LOWER
70S AND SURFACE TEMPERATURES WARM INTO THE LOWER 80S. SURFACE
TEMPERATURES ARE FORECAST TO CLIMB INTO THE UPPER 70S TO THE LOWER
80S BUT DEWPOINTS WILL BE MUCH LESS...IN THE 62 TO 65 DEGREE
RANGE. THINKING 0-3KM MUCAPE VALUES IN THE 1200 TO 1700 J/KG RANGE
SEEM MORE REALISTIC. THE POTENTIAL EXIST FOR A FEW ROUNDS OF
SHOWERS AND STORMS ALONG THE PREFRONTAL TROUGH AND ANOTHER TONIGHT
AS THE UPPER TROUGH DIVES SOUTHEAST INTO THE REGION AND THE COLD
FRONT EDGES CLOSER TO THE FORECAST AREA. IF STORMS HOLD OFF UNTIL
MID TO LATE AFTERNOON...LARGE HAIL AND DAMAGING WINDS MAY OCCUR
WITH THE STRONGER STORMS. THE FRONT IS EXPECTED TO PUSH THROUGH
THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY MORNING TAKING
THE BULK OF THE INSTABILITY SOUTH OF THE AREA. HOWEVER...THE
TROUGH WILL MOVE IN ITS WAKE WITH SHOWER AND ISOLATED STORM
CHANCES PERSISTING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 357 AM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS WILL BE ONGOING FRIDAY MORNING...ESPECIALLY
ACROSS CENTRAL AND FAR SOUTHWEST WISCONSIN. THE UPPER LEVEL TROUGH
THEN DIVES INTO THE AREA LATE FRIDAY MORNING INTO FRIDAY AFTERNOON.
SCATTERED TO NUMEROUS SHOWERS WILL DEVELOP AS COLDER AIR ALOFT MOVES
INTO THE AREA. THE TROUGH WILL REMAIN OVER THE REGION FRIDAY NIGHT
INTO SATURDAY AS AN UNSEASONABLY COLD AIRMASS MOVES IN. 850 MB
TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE -2.0 TO -2.5
RANGE...SUGGESTING NEAR RECORD COOL TEMPERATURES FOR THIS TIME OF
YEAR. HIGH TEMPERATURES ON SATURDAY WILL STRUGGLE TO GET OUT OF THE
60S. IN FACT...IT APPEARS LA CROSSE MAY SEE A RECORD LOWEST HIGH
TEMPERATURE FOR THE DATE. LATEST FORECAST IS 68 DEGREES AT LA
CROSSE. THIS WOULD BREAK THE OLD RECORD OF 69 SET BACK IN 1981.
FORECAST MODELS SUGGEST THERE WILL BE ENOUGH INSTABILITY ON SATURDAY
AFTERNOON TO GENERATE SOME SHOWERS...MAINLY ALONG AND NORTH OF
INTERSTATE 94. THIS MAKES SENSE LOOKING AT FORECAST SOUNDINGS
SHOWING SOME WEAK CAPE DURING THE AFTERNOON HOURS. HAVE ADDED A
SLIGHT CHANCE OF SHOWERS OVER CENTRAL WISCONSIN TO ACCOUNT FOR THIS.
ANOTHER SHORTWAVE ROTATES INTO NORTHERN WISCONSIN SATURDAY
NIGHT...BRINGING ADDITIONAL CHANCES FOR SHOWERS OVER NORTH CENTRAL
WISCONSIN. FLOW ALOFT THEN FINALLY STARTS TO TRANSITION TO ZONAL
EARLY NEXT WEEK AS THE TROUGH PUSHES EAST OF THE REGION INTO THE
EASTERN GREAT LAKES. TEMPERATURES WILL RETURN TO MORE SEASONABLE
VALUES FOR NEXT WEEK WITH HIGH CLIMBING BACK INTO THE UPPER 70S TO
AROUND 80. SEVERAL EMBEDDED WAVES IN THE ZONAL FLOW WILL BRINGING
PERIODIC CHANCES FOR SHOWERS AND STORMS MAINLY MONDAY NIGHT
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 24 2013
WIDELY SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS EVENING OVER
CENTRAL MINNESOTA AND ARE DROPPING SOUTHEAST AHEAD OF A WEAK SHORT
WAVE TROUGH. THE 25.01Z HRRR WOULD SUGGEST THESE WOULD DISSIPATE
BEFORE REACHING THE AREA. HOWEVER...IR SATELLITE INDICATES THE
CLOUD TOPS ARE NOT SHOWING ANY SIGNS OF WARMING YET AND GIVEN THE
CURRENT MOVEMENT...THESE COULD IMPACT KRST BEFORE SUNRISE. HAVE
THROWN IN A VCSH STARTING AT 10Z TO INDICATE THIS ACTIVITY COULD
BE GETTING CLOSE TO THE AREA. AFTER THAT...STILL HAVE VERY LOW
CONFIDENCE ON HOW THURSDAY IS GOING TO PLAY OUT. THE 25.00Z NAM
DID NOT SHIFT MUCH FROM THE 24.18Z RUN...IF ANYTHING...IT MIGHT BE
EVEN A LITTLE WEAKER WITH THE FORCING SIGNALS. NOT MUCH MOISTURE
CONVERGENCE OR MOISTURE TRANSPORT IS SHOWN TO BE OCCUR ALONG OR
INTO EITHER THE PRE-FRONTAL TROUGH OF SURFACE FRONT. NOT A LOT OF
DYNAMIC FORCING IS INDICATED EITHER AS THE MAIN SHORT WAVE TROUGH
IN THE NORTHWEST FLOW ALOFT WILL STILL BE OVER FAR NORTHERN
MINNESOTA INTO SASKATCHEWAN AND WILL BE POSITIVELY TILTED WHILE
ANOTHER SHORT WAVE TROUGH WILL BE MOVING OUT OF THE DAKOTAS
TOWARD IOWA FROM THE ONGOING CONVECTION OVER MONTANA. HAVE
MAINTAIN THE PREVIOUS THINKING OF SOME CONVECTION GOING UP IN THE
LATE MORNING TO EARLY AFTERNOON ALONG THE PRE-FRONTAL TROUGH...WHICH
THE HRRR ALSO SHOWS OCCURRING. THIS SHOULD MOVE OUT DURING THE
AFTERNOON WITH A SHORT PERIOD OF RECOVERY BEFORE THE FRONT COMES
IN WITH SOME ADDITIONAL SCATTERED CONVECTION. THIS WILL LIKELY END
DURING THE MID TO LATE EVENING BUT WILL LET THE NEXT FORECAST
DETAIL THAT ASPECT. CONFIDENCE STILL REMAINS TOO LOW TO INCLUDE
ANYTHING OTHER THAN VCTS AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT WED JUL 24 2013
.SHORT TERM...(TONIGHT AND THURSDAY)
ISSUED AT 328 PM CDT WED JUL 24 2013
MAIN FORECAST CONCERNS THIS PACKAGE...INCREASING SHRA/TSRA CHANCES
THRU THU AND SEVERE POTENTIAL WITH THEM.
DATA ANALYSIS AT 18Z HAD BROAD BUT GENERALLY WEAK AREA OF HIGH
PRESSURE ACROSS THE NORTH-CENTRAL CONUS...CENTERED OVER WI TO NEB.
A WEAK TROUGH OF LOW PRESSURE WAS LOCATED OVER EAST CENTRAL TO SOUTH
CENTRAL MN...IN RESPONSE TO A WEAK SHORTWAVE SEEN IN WV IMAGERY
DROPPING SOUTHEAST ACROSS MN. VIS IMAGERY SHOWED CUMULUS DEVELOPED
RAPIDLY ACROSS MUCH OF THE REGION LATE THIS MORNING...UNDER THE
COOL 850-700MB AIRMASS. CLOUDS AND SOME ISOLATED SPRINKLES THIS
MORNING HELPING KEEP TEMPS ON THE COOL SIDE TODAY...WITH MID DAY
READINGS ONLY IN THE LOW-MID 70S OVER MUCH OF MN/IA/WI.
24.12Z MODELS AGAIN LOOK TO HAVE INITIALIZED WELL...BUT FOR GFS ON
THE LOW SIDE WITH SFC DEW POINTS FROM ND/SD THRU MN/WI. SOLUTIONS
QUITE SIMILAR FOR TONIGHT/THU AND HAVE TRENDED BACK TO BEING A BIT
FASTER WITH THE FRONT APPROACHING THE AREA LATE THU. HOWEVER GFS
CONTINUES TO LAG THE CONSENSUS AT 00Z FRI. DPROG/DT OF 500MB HGTS
AT 24.12Z SHOWED THE MODEL RUNS OF 22.12Z AND 23.12Z VERIFIED WELL
ACROSS NOAM/EASTERN PAC. SOLUTION CONTINUE TO OFFER A TIGHTENING
CONSENSUS /AT LEAST AT 500MB/ AS A STRONGER SHORTWAVE DROPS THRU
THE NORTHWEST FLOW ALOFT TOWARD THE AREA TONIGHT/THU. TREND FAVORING
A COMPROMISE ON THE STRENGTH OF THE TROUGH BUT NOW FAVORING FASTER OF
EARLIER MODELS BY 00Z FRI. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED
MODELS GOOD WITH THE HIGH OVER THE REGION AND WEAK TROUGH OVER MN...
AND REASONABLE ENOUGH WITH SFC DEW POINTS OVER THE CENTRAL CONUS.
PER WV IMAGERY MODELS LOOK TO BE STRUGGLING A BIT WITH WEAK SHORTWAVE
RIPPLES IN THE NORTHWEST FLOW FROM SASKAT/MAN TO WI BUT LOOKED
REASONABLE WITH FEATURES UPSTREAM OVER WESTERN CAN TO IMPACT THE
AREA THU/THU NIGHT. NO CLEAR MODEL FAVORITE AND WITH THE TREND
TOWARD A COMMON CONSENSUS...FAVORED THE CONSENSUS. SHORT TERM FCST
CONFIDENCE REMAINS GENERALLY GOOD THIS CYCLE.
IN THE SHORT TERM...QUESTION REMAINS WILL WEAK 925-850MB WARM/
MOISTURE ADVECTION ALONG WITH SOME ISENTROPIC LIFT/WEAK INSTABILITY
BE ENOUGH FOR ISOLATED SHRA/TSRA LATE THIS AFTERNOON/EARLY THIS
EVENING. SHORT TERM FORECASTER ADDED SOME SPRINKLES TO THE NORTHWEST
HALF OF THE FCST AREA FOR THE REST OF THIS AFTERNOON. WILL LEAVE THIS
EVENING DRY FOR NOW AS APPEARS ANY ACTIVITY WILL BE STRONGLY DIURNAL.
MAIN AXIS OF MOISTURE/MOISTURE TRANSPORT/ INSTABILITY REMAINS WEST/
NORTH OF THE FCST AREA TONIGHT...CLOSER TO THE DEVELOPING/APPROACHING
SFC TROUGH/FRONT. LEFT OVERNIGHT PORTION OF THE FCST DRY.
EVEN THOUGH MODELS ARE QUITE SIMILAR ALOFT...PLENTY OF MODEL DETAIL
DIFFERENCES IN THE LOWER/SFC LEVELS AS THE TROUGH/FRONT APPROACHES
ON THU. CONSENSUS HAS PW VALUES INCREASING INTO THE 1.5 TO 1.75 INCH
RANGE AHEAD OF THE FRONT ON THU. MU CAPE VALUES BUILD INTO THE 1.5
TO 2.5K J/KG RANGE BY MID-DAY THU. QUESTION IS HOW QUICKLY
CONVECTION FIRES ON THU. SOUNDINGS SHOWING LITTLE CAPPING BY MID-
DAY AND WITH APPROACH OF THE SHORTWAVE/FALLING HGTS/DIVERGENCE
ALOFT...CONVECTION MAY FIRE BY LATE MORNING JUST NORTHWEST OF THE
FCST AREA...THEN SPREAD INTO THE AREA DURING THE EARLY AFTERNOON.
DEBRIS CLOUDS WOULD QUICKLY LIMIT ADDITIONAL WARMING/
DESTABILIZATION...WITH ANY SEVERE THREAT BEING SHORT-LIVED/
LIMITED. LATER CONVECTIVE DEVELOPMENT CLOSER TO THE APPROACHING
FRONT WOULD ALLOW FOR MORE MOISTURE/INSTABILITY TO MOVE INTO THE
AREA...WITH MORE OF A SEVERE THREAT LATER IN THE AFTERNOON/EARLY
EVENING AS THE CONVECTION MOVES INTO THE FCST AREA. SEE SWODY2 FOR
MORE DETAILS OF THE SEVERE THREAT. WOULD EXPECT CONVECTIVE
INITIATION TO BE TIED MORE TO THE FRONT...THEN MOVE INTO THE AREA
DURING THE MID/LATE AFTERNOON HOURS. LEFT SHRA/TSRA CHANCES THRU
THU MORNING QUITE LOW. THEN RAISED THEM THRU THE AFTERNOON...INTO
THE 50-70 PERCENT RANGE BY LATE AFTERNOON ACROSS THE NORTHWEST
HALF OF THE FCST AREA. USED A MODEL/ENSEMBLE CONSENSUS FOR LOWS/
HIGHS TONIGHT/THU...THOUGH CONCERNED IF CONVECTION FIRES EARLY...
THU MAY BE TOO WARM UNDER PLENTY OF CLOUDS AND SCT SHRA/TSRA DURING
THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM CDT WED JUL 24 2013
FORECAST CONCERNS IN THE THU NIGHT THRU SAT NIGHT PERIOD INCLUDE
SHRA/TSRA CHANCES THU NIGHT/FRI WITH THE TROUGH/FRONTAL
PASSAGE...THEN COOL TEMPERATURES FRI NIGHT THRU SAT NIGHT.
24.12Z MODELS REMAIN VERY SIMILAR THU NIGHT/FRI AS THE MAIN
SHORTWAVE DROPS ACROSS THE AREA. MODELS THEN BEGIN TO DIVERGE WITH
WHAT HAPPENS/WHERE THE MID LEVEL LOW ENDS UP BY LATE SAT/SAT NIGHT.
TREND OF THE MORE CONSISTENT AND VERY SIMILAR GFS/ECMWF RUNS IS
TOWARD A MORE SOUTHWEST POSITION OF THE MID LEVEL LOW BY 00Z SUNDAY.
FAVORED A MODEL/ENSEMBLE CONSENSUS WEIGHTED TOWARD THE GFS/ECMWF FOR
THU NIGHT THRU SAT NIGHT...WITH AVERAGE TO GOOD FCST CONFIDENCE.
SFC-700MB TROUGH/FRONT SLIDES INTO/ACROSS THE AREA THU NIGHT/FRI
MORNING. MODEST LOWER LEVEL THERMODYNAMIC AND UPPER LEVEL DYNAMIC
FORCING/LIFT TO MOVE ACROSS THE AREA THU NIGHT. FAVORING A SCENARIO
WITH BULK OF THE CONVECTION ACCOMPANYING THE SFC-850MB FRONT/TROUGH
RAISED SHRA/TSRA CHANCES THU NIGHT INTO THE 70-80 PERCENT RANGE AND
ADDED SOME TIMING AS THE FRONT MOVES ACROSS THE FCST AREA. WITH THE
CONSENSUS NOW TOWARD A FASTER FRONTAL PASSAGE...TRENDED PRECIP
CHANCES TO 30 PERCENT OR LESS BY FRI AFTERNOON. WITH THE LOW LEVEL
COLD ADVECTION/STABILIZATION BY FRI AFTERNOON...ONLY CARRIED
MENTION OF SHRA AFTER 18Z. MDT/STRONG LOW LEVEL COLD ADVECTION
SPREADS ACROSS THE AREA FRI/FRI NIGHT. DRIER SFC-700MB AIR TRIES TO
WRAP ACROSS THE AREA BEHIND THE SFC-500MB LOW BUT BUT SOME
DEFORMATION BAND MOISTURE MAY WRAP AROUND THE LOW AND ACROSS THE
AREA UNDER THE COOL TEMPS AND CYCLONIC FLOW ALOFT. THIS MOISTURE/
CLOUDS WILL BATTLE THE SUBSIDENCE IN THE WAKE OF THE LOW. DID
INCREASE CLOUD COVER OVER AT LEAST THE NORTHEAST HALF OF THE FCST
AREA FOR LATE FRI/FRI NIGHT. CLOUDS/MODEST NORTHWEST WINDS ON FRI
WILL KEEP HIGHS FROM RISING MUCH. NORTHWEST GRADIENT WINDS OF 5-
10KTS AND POTENTIAL FOR CLOUD COVER WILL KEEP LOWS FROM FALLING OFF
TOO FAR FRI NIGHT. CONTINUED LOW LEVEL DRYING INDICATED FOR SAT/SAT
NIGHT AS THE LOW MOVES AWAY AND SFC-850MB HIGH PRESSURE BUILDS INTO
THE REGION. BY 00Z SUN...850MB TEMPS STILL PROGGED TO BE SOME 1.5
TO 2 STANDARD DEVIATIONS BELOW NORMAL. FRI THRU SAT NIGHT/SUN
MORNING LOOKING TO BE A COOL...AUTUMN LIKE COUPLE DAYS. TRENDED
HIGHS/LOWS FOR FRI THRU SAT NIGHT TOWARD COOLER OF GUIDANCE VALUES.
MEDIUM RANGE MODEL RUNS OF 24.00Z IN DECENT AGREEMENT WITH EACH
OTHER AND THEIR PREVIOUS RUNS ON SUNDAY. TREND FAVORS SLOWER/
FURTHER SOUTHWEST OF EARLIER MODELS WITH THE MID LEVEL LOW NORTH OF
LK SUPERIOR. BY MONDAY SOLUTIONS DIVERGE WITH HOW QUICKLY THIS LOW
LIFTS NORTHEAST AND GIVES UP ITS INFLUENCE ON THE REGION. THESE
DIFFERENCES LEAD TO BIGGER DIFFERENCES BY TUE AS SHORTWAVES MOVE
EAST THRU THE MAIN BELT OF WESTERLIES ACROSS SOUTHERN CAN/NORTHERN
CONUS. BY TUE/WED...GFS/ECMWF WERE 180 DEGREES OUT OF PHASE WITH
TIMING OF STRONGER WAVES THRU THE FLOW BUT 24.12Z GFS HAS TRENDED
MORE SIMILAR TO THE ECMWF. GIVEN MODELS LOOKING TO DEAL WITH AN
ACTIVE QUASI-ZONAL FLOW NEXT WEEK...THE LESSER RUN-TO-RUN
CONSISTENCY SEEN IN THE DAY 5-6-7 PERIOD NOT SURPRISING. DAY 4-7
FCST CONFIDENCE AVERAGE AT BEST THIS CYCLE...AND WITHOUT A
PREFERRED MODEL WILL SIDE NEAR THE MODEL/ENSEMBLE CONSENSUS.
SUNDAY CONTINUES TO LOOK LIKE A DRY/QUIET...SEASONABLY COOL DAY AS
THE CAN HIGH PRESSURE CENTERED OVER THE REGION IN THE MORNING SLIPS
SOUTHEAST THRU THE DAY. WITH THE MODELS THEN VARYING ON TIMING OF
STRONGER...MORE TRACKABLE SHORTWAVES THRU THE FLOW...FCST GETS
MUDDY FOR EARLY NEXT WEEK. THERE WILL BE DRY PERIODS/DAYS IN THE
MON-WED PERIODS BUT WHICH THESE WILL BE IN NEARLY IMPOSSIBLE TO
DETERMINE WITH THE VARIETY OF SOLUTIONS AMONG THE RECENT MODEL
SETS. SMALL SHRA/TSRA CHANCES FOR MUCH OF THE MON-WED PERIOD
REASONABLE FOR NOW UNTIL THE DETAILS CAN BE SORTED OUT. AFTER THE
COOL WEEKEND...IT DOES APPEAR TEMPS WILL WARM BACK TO NEAR NORMAL
BY THE MIDDLE OF NEXT WEEK AS THE FLOW TRANSITIONS TO WESTERLY.
MODEL CONSENSUS HIGHS/ LOWS FOR THE DAY 4-7 PERIOD LOOK WELL
TRENDED AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 24 2013
WIDELY SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS EVENING OVER
CENTRAL MINNESOTA AND ARE DROPPING SOUTHEAST AHEAD OF A WEAK SHORT
WAVE TROUGH. THE 25.01Z HRRR WOULD SUGGEST THESE WOULD DISSIPATE
BEFORE REACHING THE AREA. HOWEVER...IR SATELLITE INDICATES THE
CLOUD TOPS ARE NOT SHOWING ANY SIGNS OF WARMING YET AND GIVEN THE
CURRENT MOVEMENT...THESE COULD IMPACT KRST BEFORE SUNRISE. HAVE
THROWN IN A VCSH STARTING AT 10Z TO INDICATE THIS ACTIVITY COULD
BE GETTING CLOSE TO THE AREA. AFTER THAT...STILL HAVE VERY LOW
CONFIDENCE ON HOW THURSDAY IS GOING TO PLAY OUT. THE 25.00Z NAM
DID NOT SHIFT MUCH FROM THE 24.18Z RUN...IF ANYTHING...IT MIGHT BE
EVEN A LITTLE WEAKER WITH THE FORCING SIGNALS. NOT MUCH MOISTURE
CONVERGENCE OR MOISTURE TRANSPORT IS SHOWN TO BE OCCUR ALONG OR
INTO EITHER THE PRE-FRONTAL TROUGH OF SURFACE FRONT. NOT A LOT OF
DYNAMIC FORCING IS INDICATED EITHER AS THE MAIN SHORT WAVE TROUGH
IN THE NORTHWEST FLOW ALOFT WILL STILL BE OVER FAR NORTHERN
MINNESOTA INTO SASKATCHEWAN AND WILL BE POSITIVELY TILTED WHILE
ANOTHER SHORT WAVE TROUGH WILL BE MOVING OUT OF THE DAKOTAS
TOWARD IOWA FROM THE ONGOING CONVECTION OVER MONTANA. HAVE
MAINTAIN THE PREVIOUS THINKING OF SOME CONVECTION GOING UP IN THE
LATE MORNING TO EARLY AFTERNOON ALONG THE PRE-FRONTAL TROUGH...WHICH
THE HRRR ALSO SHOWS OCCURRING. THIS SHOULD MOVE OUT DURING THE
AFTERNOON WITH A SHORT PERIOD OF RECOVERY BEFORE THE FRONT COMES
IN WITH SOME ADDITIONAL SCATTERED CONVECTION. THIS WILL LIKELY END
DURING THE MID TO LATE EVENING BUT WILL LET THE NEXT FORECAST
DETAIL THAT ASPECT. CONFIDENCE STILL REMAINS TOO LOW TO INCLUDE
ANYTHING OTHER THAN VCTS AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1142 PM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 834 PM CDT FRI JUL 26 2013
WEAKENING LINE OF CONVECTION HAS PROGRESSED ABOUT A THIRD OF THE
WAY ACROSS THE CWA...EXTENDING FROM LINCOLN TO WINCHESTER AT 830
PM. HAVE HAD SEVERAL REPORTS OF A QUICK HALF TO 1 INCH OF RAIN
WITH THIS BAND. FURTHER EAST...HAVE HAD SCATTERED SHOWERS MUCH OF
THE EVENING. NOT MUCH IN THE WAY OF INSTABILITY ACROSS THE EASTERN
HALF OF THE CWA...SO THE CURRENT LINE SHOULD CONTINUE TO SLOWLY
WEAKEN. HAVE UPDATED THE GRIDS ACROSS THE EAST TO MENTION ONLY
ISOLATED THUNDER WITH SCATTERED SHOWERS PREVAILING.
FRONTAL BOUNDARY WAS APPROACHING THE ILLINOIS RIVER AND SKIES
WERE QUICKLY CLEARING BEHIND IT...ALTHOUGH SOME COLD-AIR
STRATOCUMULUS CONTINUES TO DROP SOUTHWARD THROUGH IOWA. DRIER AIR
IS NOT TOO FAR BEHIND THE FRONT WITH DEW POINTS DOWN TO THE UPPER
40S IN PORTIONS OF CENTRAL IOWA. WITH THIS TYPE OF DRIER AIR
ADVECTING IN...CURRENT LOW TEMPERATURE FORECAST STILL LOOKS
REASONABLE...ALTHOUGH SOME UPDATES WERE DONE TO THE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1142 PM CDT FRI JUL 26 2013
FRONTAL BOUNDARY APPROACHING KCMI AS MIDNIGHT APPROACHES...WITH
WINDS TO SWING AROUND TO THE NORTHWEST SHORTLY. REMNANTS OF THE
SHOWERS WERE SOUTH OF THE TAF SITES AND NO ADDITIONAL RAIN IS
EXPECTED. HAVING SOME ISSUES WITH MVFR CEILINGS ALONG THE
BOUNDARY...DIPPING BELOW 1000 FEET AT TIMES AROUND KCMI. BACK EDGE
OF THE CLOUDS HAS REACHED KSPI AND WILL MOVE EAST OF THE REMAINING
TAF SITES BY 11Z.
LATER IN THE DAY ON SATURDAY...SOME GUSTY WINDS TO AROUND 15 KNOTS
ARE EXPECTED AS A DEEP UPPER LOW SPINS OVER WISCONSIN AND UPPER
MICHIGAN. COLD AIR ALOFT WILL LEAD TO MORE DIURNAL CLOUD
DEVELOPMENT AROUND 4000 FEET...AND MAY YIELD A COUPLE SPRINKLES AS
WELL. HUMIDITY PLOTS SHOWING MORE SUBSTANTIAL CEILINGS TRYING TO
WORK THEIR WAY SOUTHWARD TOWARD THE TAF SITES AFTER 00Z. HAVE KEPT
EVENING CLOUDS IN THE SCATTERED CATEGORY FOR NOW...AS THE CORRIDOR
ALONG I-74 IS ON THE PERIPHERY OF THIS SLUG OF CLOUDS.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT FRI JUL 26 2013
SHOWERS AND STORMS WILL BE POSSIBLE THROUGH TONIGHT ALONG A COLD
FRONT...THEN AN UNSEASONABLY COOL AIR MASS WILL SETTLE INTO
ILLINOIS FOR SATURDAY AND SUNDAY. A WARMING TREND WILL BEGIN ON
MONDAY AS UPPER FLOW BECOMES MORE ZONAL FROM WEST TO EAST. ONE LOW
PRESSURE SYSTEM IS EXPECTED TO EJECT FROM THE SOUTHERN PLAINS
ACROSS SOUTHERN ILLINOIS MONDAY NIGHT AND TUESDAY. A WEAKER UPPER
TROUGH WILL SWING ACROSS NORTHERN ILLINOIS ON THURSDAY...SETTING
UP NORTHWEST FLOW ALOFT THROUGH FRIDAY.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
19Z SURFACE ANALYSIS SHOWS THE COLD FRONT APPROACHING THE
IOWA/ILLINOIS BORDER. RADAR SHOWS A NARROW LINE OF SHOWERS AND
STORMS ALONG THE FRONT IN IOWA...AND FARTHER SOUTHEAST AHEAD OF
THE FRONT IN EASTERN MISSOURI AND FAR WESTERN ILLINOIS. A BROAD
COVERAGE OF LIGHT RAIN SHOWERS EXTENDED ACROSS MUCH OF CENTRAL
ILLINOIS AND INTO WEST CENTRAL INDIANA. MOST AREAS IN CENTRAL
ILLINOIS WERE SEEING LESS THAN 0.10" OF RAIN OUT AHEAD OF THE
FRONT.
4KM NCEP AND HRRR OUTPUT INDICATE THE LINE WILL MAINTAIN SOME
INTENSITY DURING THE DAYLIGHT HOURS...BUT WEAKEN WITH SUNSET AS
THE LINE OF STORMS REACHES THE I-55 CORRIDOR. TIMING BASED ON
RADAR AND HRRR HAS THE LINE OF STORMS GENERALLY INTO INDIANA BY
08Z/3 AM. THE GFS/NAM/ECMWF/GEM ARE NOT FAR OFF FROM THAT
ASSESSMENT...SO WE HAVE UPDATED THE POPS LIKEWISE. BASICALLY,
SCATTERED COVERAGE IS EXPECTED ALONG AND AHEAD OF THE FRONT, SO
CHANCE POPS WERE USED /30-50 PCT/. SOME AREAS MAY SEE A STRONGER
UPDRAFT AND RECEIVED 0.25" RAIN IN A SHORT TIME, WHILE NEARBY
AREAS SEE LITTLE TO NO RAIN.
SATURDAY WILL FEATURE THE ARRIVAL OF A CHILLY CANADIAN AIR MASS AS
AIRFLOW BECOMES NORTH-NORTHWEST THROUGH A DEEP LAYER OF THE
ATMOSPHERE. 850MB TEMPS WILL DROP TO +6C IN OUR NORTH WITH 9-10C IN
THE SOUTH. ANY DAYTIME HEATING WILL CREATE STEEP LOW LEVEL LAPSE
RATES...WHICH WILL WORK TOGETHER WITH INCREASING BULK SHEAR AND
POSITIVE VORTICITY ADVECTION TO KICK OFF A FEW SHOWERS SATURDAY
AFTERNOON. MOST AREAS WILL PROBABLY REMAIN DRY...AND ANY RAIN THAT
DOES DEVELOP WILL NOT ADD UP TO 0.01"...SO WE WENT WITH SCATTERED
SPRINKLES FOR OUR NORTHERN COUNTIES SAT AFTN.
CLOUD COVER WILL DEVELOP QUICKLY IF ANY SUNSHINE BREAKS THROUGH
FOR ANY LENGTH OF TIME...WHICH WILL HELP TO KEEP HIGHS IN THE
70-73 DEG RANGE. WOULD NOT BE SURPRISED IF SOME LOCATIONS DO NOT
REACH 70 IF THE 6C LINE AT 850MB DOES REACH OUR COUNTIES. DRY
ADIABATIC MIXING OF 6C FROM 850MB WOULD ONLY PRODUCE A HIGH OF
66F. ANY SHOWERS WILL QUICKLY DISSIPATE WITH THE APPROACH OF
SUNSET.
RECORD OR NEAR RECORD LOWS ARE FORECAST FOR SATURDAY NIGHT.
CLEARING SKIES WILL BE A KEY COMPONENT OF THAT HAPPENING...BUT ALL
INDICATIONS ARE THAT CLOUDS WILL BE DIURNALLY DRIVEN AND SHOULD
DISSIPATE SAT EVE. LOW 50S WILL BE COMMON ACROSS THE FORECAST
AREA. RECORD LOW FOR PIA AND SPI SAT NIGHT IS 53.
SUNDAY MAY BE A CARBON COPY OF SATURDAY...WITH THE UPPER TROUGH
LINGERING ACROSS THE WESTERN GREAT LAKES AND INTO EASTERN
ILLINOIS, AND LITTLE CHANGE IN THE AIR MASS. SPOTTY SHOWERS AND
SPRINKLES WILL BE POSSIBLE...MAINLY IN THE NORTH CLOSER TO THE
COLDER AIR.
MONDAY WILL START A WARMING TREND AS THE UPPER TROUGH AXIS DEPARTS
TO THE EAST AND WESTERLY FLOW DEVELOP. THAT WILL SET THE STAGE FOR
A PROGRESSIVE LOW TO MOVE FROM THE PLAINS ACROSS SOUTHERN MISSOURI
AND SOUTHERN IL. SOME LOCALLY HEAVY RAIN WILL BE POSSIBLE LATER
MONDAY NIGHT AS THE LOW APPROACHES AND A WARM FRONT DEVELOPS
NEAR OUR SOUTHERN COUNTIES. THE MODELS HAVE TRENDED FARTHER SOUTH
WITH THE TRACK OF THE LOW THE LAST 2 MODEL RUNS...SO IT IS NOT OUT
OF THE QUESTION THAT LATER RUNS TAKE IT EVEN FARTHER SOUTH. WE
REDUCED LIKELY POPS TO CHANCE MONDAY NIGHT TO TREND DOWN...BUT
ADDED SOME LIKELY TO TUES IN OUR FAR SOUTHERN COUNTIES AS
GFS/ECMWF AGREE ON DECENT COVERAGE OF SHOWERS/STORMS DURING THE
DAY IN SOUTHERN IL RIGHT NOW. PRECIP WILL DIMINISH TUESDAY NIGHT
AS THE BULK OF THE FORCING FOR PRECIP DEPARTS TO THE EAST WITH THE
LOW.
WARMING WILL DEVELOP AHEAD OF THE LOW...AND DEWPOINTS WILL CLIMB
BACK INTO THE 60S WITH THE SYSTEM. LOCALLY HEAVY RAIN MAY DEVELOP
IN THE STRONGER STORMS...WITH RAINFALL RATES OF 1-2 INCHES PER
HOUR.
LONG TERM...WEDNESDAY THROUGH FRIDAY.
WEDNESDAY LOOKS MAINLY DRY AT THIS POINT, ALTHOUGH SOME ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE AS NORTHWEST FLOW RETURNS AND
500MB SHORTWAVES MOVE INTO THE AREA. DEWPOINTS WILL CLIMB INTO THE
UPPER 60S BY WEDNESDAY...SO MUGGY FEELING AIR WILL RETURN AS HIGHS
CLIMB INTO THE LOWER 80S. SOME MID 80S FOR HIGHS WILL BE POSSIBLE
ON THURSDAY AND FRIDAY AS 850MB TEMPS CLIMB BACK TO 14-16C. RAIN
CHANCES INCREASE MORE DRAMATICALLY ON FRIDAY PER THE GFS...WITH A
STRONGER SYSTEM DROPPING SOUTHEAST FROM THE NORTHERN PLAINS. THE
ECMWF LAGS THE GFS BY 24 HRS WITH THAT FEATURE.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
401 AM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT JUL 27 2013
AN ABNORMALLY COOL AND DRY AIRMASS IS CURRENTLY IN PLACE OVER THE
CENTRAL AND NORTHERN PLAINS IN THE FORM OF A SURFACE RIDGE WHICH
EXTENDS FROM SOUTHERN KANSAS NORTHWARD THROUGH NEBRASKA AND INTO THE
NORTHERN PLAINS. THIS AIRMASS IS CHARACTERIZED BY TEMPS IN THE UPPER
40S TO MID 50S ACROSS EASTERN NEBRASKA AND IN THE UPPER 50S TO LOWER
60S THROUGHOUT EASTERN KANSAS. EXPECT THESE TEMPS TO CONTINUE TO
DROP THROUGH THE REST OF THE OVERNIGHT HOURS AND SETTLE AROUND THE
MID TO UPPER 50S FOR OUR FORECAST AREA. RADAR TRENDS SHOW A VERY
WEAK COMPLEX OF SHOWERS AND THUNDERSTORMS IN CENTRAL NEBRASKA. THIS
COMPLEX LOOKS TO BE ASSOCIATED WITH SOME MODERATE ISENTROPIC LIFT
ALONG THE 310K THETA E SURFACE. SOMEWHAT SURPRISING IS THE AMOUNT OF
LIGHTNING DETECTED WITH THESE STORMS AS RAP SOUNDINGS ONLY INDICATE
AROUND 100-200 J/KG OF ELEVATED INSTABILITY FOR THESE STORMS TO WORK
WITH. NONETHELESS HAVE GONE WITH A CHANCE OF ISOLATED THUNDERSTORMS
FOR THE NORTH CENTRAL AND CENTRAL PART OF THE STATE...INCLUDING THE
FAR WESTERN ZONES OF THE FORECAST AREA THROUGH THE MORNING
HOURS...BEFORE GRADUALLY DISSIPATING DURING THE AFTERNOON. WITH THE
COOLER/DRIER AIRMASS IN PLACE OVER THE FORECAST AREA EXPECT TEMPS TO
BE WELL BELOW SEASONAL NORMS...WITH HIGHS REACHING THE MID TO UPPER
70S...WITH PERHAPS A FEW AREAS REACHING 80 DEGREES. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING AS ANOTHER ROUND OF WARM AIR ADVECTION SHOWERS
COMMENCE ACROSS WESTERN AND CENTRAL KANSAS. EXPECT THESE SHOWERS TO
SPILL INTO OUR AREA AND SPREAD EASTWARD OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING. ANOTHER COOL NIGHT IS IN STORE FOR THE AREA ON
SATURDAY NIGHT...AS LOWS WILL LIKELY DROP INTO THE LOWER TO MID 50S
ACROSS THE EASTERN HALF OF THE CWA...WHILE AREAS IN THE WESTERN HALF
WILL STAY IN THE MID TO UPPER 50S.
.LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 324 AM CDT SAT JUL
27 2013
MOISTURE AND PRECIP SLOWLY INCREASE FROM WEST TO EAST ACROSS
EASTERN KANSAS ON SUNDAY...BECOMING LIKELY SUNDAY NIGHT INTO
MONDAY. HIGHS SUNDAY WITH INCREASING CLOUD COVER AND RAIN CHANCES
EXPECTED TO BE IN THE MIDDLE 70S FOR MUCH OF THE AREA. BY 12Z
MONDAY...SURFACE LOW OVER THE TX PANHANDLE GETS A BOOST FROM A
PASSING SHORTWAVE TROF ROLLING OFF THE HIGH PLAINS...INCREASING
MOISTURE ADVECTION AND THE LLJ AND FOCUSING PRECIPITATION ACROSS
EASTERN KANSAS. STILL SOME DISCREPANCIES AS TO HOW FAR NORTH THE
BRUNT OF THE RAIN WILL FALL...WITH NAM ALONG THE I70 CORRIDOR AND
EC FARTHER SOUTHWARD TOWARD SE KS. WILL FAVOR POPS OVER THE
SOUTHERN HALF OF THE AREA AND NOTE THAT PRECIP AMOUNTS COULD BE A
FEW INCHES OR MORE IN SOME LOCATIONS. NO WATCH AT THIS TIME BUT
WILL NEED TO MONITOR EVOLUTION FOR POSSIBLE LOCALIZED FLOODING
CONCERNS ON MONDAY.
SYSTEM MOVES EAST BY MONDAY NIGHT AND EXPECT PRECIP TO END QUICKLY
W TO E EARLY TUESDAY. MAINLY DRY CONDITIONS FORECAST THROUGH
THURSDAY. ZONAL FLOW SLOWLY TRANSITIONS TO WNW FLOW AROUND THE
SOUTHERN UPPER HIGH...AND THIS SLOWLY WARMS TEMPERATURES INTO THE
LOWER 80S TUESDAY TO THE UPPER 80S BY THURSDAY. MAY SEE THE NEXT
CHANCE FOR RAINFALL ON FRIDAY AS ANOTHER SW TROF TRAVERSES THROUGH
THE FLOW BUT HAVE NOT GONE TOO HIGH ON CHANCES THIS FAR OUT.
SURFACE FRONT EXTENDS FROM LOW
OVER THE TX PANHANDLE AND TO THE NE..AND AM SEEING A LITTLE BETTER
AGREEMENT IN BRINGING PRECIP BULLSEYUE INTO NE KS BY THE AFTERNOON
HOURS. SOME SUGGESTION BY THE ECMWF THAT HEAVIEST RAIN WOULD FALL
TO THE SOUTH OF THE AREA...BUT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1111 PM CDT FRI JUL 26 2013
VFR PREVAILS AT KTOP/KFOE/KMHK WITH FOCUS BEING ON OVERNIGHT FOG
POTENTIAL AND POSSIBLE SHOWERS SATURDAY. MID LEVEL CLOUDS OBSERVED
OVER SOUTH CENTRAL NEBRASKA WILL SHIFT SOUTHEAST TOWARDS SITES
OVERNIGHT. THIS FACTOR COMBINED WITH DRIER AIR AT THE LOW LEVELS
AND WINDS THRU 2KFT STAYING MIXY SHOULD KEEP DENSE FOG POTENTIAL
LOW. WIDELY SCATTERED SHOWERS PUSHING SOUTHEAST OVERNIGHT MAY
STILL REACH KMHK AFT 14Z. OTHERWISE NORTH WINDS SHOULD RESIDE
NEAR 10 KTS BEFORE WEAKENING TO AROUND 5 KTS AFT 11Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEIGHTON
LONG TERM...67
AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS GAYLORD MI
140 AM EDT SAT JUL 27 2013
.SYNOPSIS...
ISSUED AT 415 PM EDT FRI JUL 26 2013
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY ADVANCE
THROUGH THE STATE...TODAY THROUGH SATURDAY. THIS SYSTEM WILL PRODUCE
A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT...WITH THE
BULK OF THE RAINFALL OCCURRING LATE THIS AFTERNOON AND THIS EVENING.
RAIN MAY BE HEAVY AT TIMES...PARTICULARLY OVER THE EASTERN UPPER
PENINSULA.
BEHIND THE FRONT...SUBSTANTIALLY COOLER AIR WILL SETTLE INTO THE
GREAT LAKES FOR THE UPCOMING WEEKEND KNOCKING TEMPERATURES DOWN TO
WELL BELOW NORMAL READINGS FOR LATE JULY. THIS WILL LEAD TO
ADDITIONAL SHOWERS DEVELOPING ON SATURDAY AND PERSISTING THROUGH
SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 132 AM EDT SAT JUL 27 2013
PUT IN SOME UPDATES FOR THE RAIN LEAVING AND THE TEMPERATURES,
FALLING A LITTLE SLOWER THAN FORECASTED EARLIER. THINK THAT THE
CLOUD OVER AND SOME OF THE WINDS ARE HOLDING THE TEMPERATURES A UP
A BIT. OTHERWISE, THE FORECAST IS LOOKING GOOD.
UPDATE ISSUED AT 949 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: CONTINUE TO REFINE NEAR TERM POPS/WX AS DEEP
MOISTURE PLUME AND ASSOCIATED HEAVIEST RAINFALL EXITS STAGE RIGHT.
IN IT/S WAKE...WE CONTINUE TO BE AHEAD OF THE SURFACE BOUNDARY
THAT IS NOW REACHING GREEN BAY WITH IT/S SIGHTS ON NORTHERN
MICHIGAN OVERNIGHT. BETWEEN THESE TWO FEATURES...HAVE SEEN A FEW
SHOWERS BUBBLE UP...AND EXPECT THAT THIS WILL REMAIN THE CASE
UNTIL FROPA...SO WILL TREND POPS TO SCATTERED THROUGH
MIDNIGHT...BUT LINGER THEM THROUGH MUCH OF THE NIGHT /PARTICULARLY
OVER MY SOUTHEASTERN ZONES.
WILL ADD FOG TO THE GOING FORECAST AFTER MIDNIGHT AS WELL AS
UPSTREAM FOG PRODUCT IMAGERY SUGGESTS THE POTENTIAL FOR AT LEAST A
TEMPORARY THINNING/BREAK IN THE CLOUDINESS...WHICH WITH THIS
EVENING/S RAIN AND CURRENT 0-2F SURFACE DEWPOINT DEPRESSIONS...
WILL LIKELY ALLOW SOME FOG TO GET GOING...BUT LIKELY NOT GET TOO
OUT OF HAND GIVEN LOW STRATUS THAT LOOKS TO ARRIVE SHORTLY BEHIND
THE SURFACE COLD FRONT.
TEMPERATURE TRENDS HAVE BEEN ADJUSTED...BUT INHERITED LOWS RANGING
FROM THE LOWER 50S OVER EASTERN UPPER...TO THE LOWER 60S OVER
NORTHEAST LOWER STILL LOOK RIGHT ON TRACK.
UPDATE ISSUED AT 616 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: GOING FORECAST DOING JUST FINE AS OF THIS
WRITING...WITH SOME COSMETIC ADJUSTMENTS TO POPS/WEATHER AS RAIN
HAS JUST ABOUT REACHED THE ENTIRE FORECAST AREA. TEMPS HAVE FALLEN
NICELY WITH ARRIVAL OF RAINFALL..SO HAVE TRENDED NEAR TERM
TEMPERATURES DOWN AS WELL.
SEVERE THREAT HAS PRETTY MUCH ENDED WITH MUCAPES DROPPING CWA-WIDE
OVER THE PAST 3 HOURS. LIGHTNING STRIKES ARE FOLLOWING SUIT AS OF
THIS WRITING...BUT SOME EMBEDDED THUNDER CERTAINLY LIKELY THROUGH
THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
SHOWERS AND STORMS ON THE UPSWING THIS AFTERNOON ACROSS THE NORTH
WOODS. WATER VAPOR DEFINITELY HELPS EXPLAIN PART OF THE REASON...WITH
AN UNSEASONABLY STRONG SHORTWAVE TROUGH GOING NEGATIVE TILT BACK
ACROSS THE WESTERN LAKES. NICE MID LEVEL SPEED MAX ALSO NOTED...WITH
CORE OF 50+ KNOT H5 WINDS ROUNDING BASE OF TROUGH INTO SOUTHWEST
WISCONSIN. DEEP LAYER DYNAMICS INTERACTING WITH IN-PLACE RESPECTABLY
MOIST AIRMASS (PWAT VALUES PER RAP GUIDANCE NEAR 1.5 INCHES) HELPING
INDUCE CONVECTIVE DEVELOPMENT. MAIN LINE OF STORMS TIED TO
WISCONSIN/CENTRAL UPPER MICHIGAN COLD FRONT/FRONTAL WAVE WHERE LOW
LEVEL CONVERGENCE/DEEP LAYER DYNAMICS ARE BETTER JUXTAPOSED. MORE
SCATTERED SHOWERS AND STORMS BREAKING OUT ACROSS NORTHERN MICHIGAN
AS SUFFICIENT ML CAPE DEVELOPMENT (UPWARDS OF 500 J/KG) AND OBVIOUS
COOLING OF EARLIER H8-H7 WARM NOSE HAS TIPPED THE SCALE TO MOIST
CONVECTIVE DEVELOPMENT. SO FAR...THINGS HAVE BEEN BEHAVING
THEMSELVES...WITH JUST SOME LOCALLY HEAVY RAIN UNDER THE HEAVIER
CELLS. APPEARS A MUCH NEEDED WIDESPREAD RAIN IS IN THE OFFING THIS
EVENING AS ABOVE DYNAMICS/MOISTURE AXIS SPREAD EAST. FORECAST
CONCERNS CENTER ON SUCH...SPECIFICALLY TIMING OF SHOWERS AND STORMS
AND SEVERE WEATHER POTENTIAL.
UPSCALE GROWTH WILL CONTINUE WITH SHOWERS/STORMS AS DEEP LAYER
DYNAMICS ONLY INCREASE HEADING INTO LATER THIS AFTERNOON AND
EVENING. COLD FRONT EXPECTED TO GET THE BOOT EAST AS MID LEVEL
SUPPORT DOES THE SAME...AND WILL SIMPLY FOLLOW IT AND BEST UPWARD QG
SUPPORT FOR SHOWER/STORM TIMING. EXPECT ALL AREAS TO GET WET...WITH
THE HEAVIEST RAINS EXPECTED ACROSS FAR NORTHWEST LOWER AND EASTERN
UPPER (LOCAL AMOUNTS IN EXCESS OF AN INCH). MAIN LINE OF ACTIVITY
EXPECTED TO SWEEP EAST THIS EVENING...EXITING OFF THE SUNRISE SIDE
DURING THE EARLY MORNING. TEMPORAL DETAIL ACCOUNTS FOR SUCH...USING
CATEGORICAL COVERAGE FOR SPATIAL PURPOSES. NOT OVERLY ENTHUSED ABOUT
SEVERE POTENTIAL...WITH ML CAPE SOMEWHAT ON THE LEAN SIDE...AND
SHOULD CONTINUE TO REMAIN SO. DEEP LAYER EFFECTIVE SHEAR INCREASES
TO OVER 30 KNOTS...WITH 40 KNOT CORE SLIDING ACROSS EASTERN UPPER
LATE THIS AFTERNOON. CANNOT RULE OUT AN ISOLATED SEVERE WIND
GUST/MARGINALLY SEVERE HAILER WITH THE STRONGEST ACTIVITY...BUT A
WIDESPREAD SEVERE EVENT IS NOT EXPECTED. INTERESTINGLY...BACKED LAKE
INDUCED FLOW ACROSS THE TIP THE MITT/NORTHEAST LOWER/EASTERN UPPER
HAS RESULTED IN A TOUCH BETTER STORM ORGANIZATION WITH EVEN SOME
HINTS OF LOW-TOPPED SUPERCELLS. SPOTTER REPORTS NEGATIVE...
HOWEVER...WITH JUST LOCALLY HEAVY RAIN REPORTED WITH THESE CELLS.
WILL DEFINITELY CONTINUE TO MONITOR. POST-FRONTAL LOW LEVEL MOISTURE
SHOULD KEEP RATHER CLOUDY CONDITIONS THROUGH THE EARLY MORNING.
INITIAL SHOT OF CAA NOT OVERLY IMPRESSIVE...WITH LOWS BY SUN-UP
RANGING FROM THE 50S WEST...TO LOWER 60S ALONG NORTHEAST LOWER
COASTLINE.
DRY SLOT CONTINUES INTO SATURDAY MORNING AS MID LEVEL LOW PRESSURE
PINWHEELS INTO NORTHERN WISCONSIN. OFF THE DECK PROFILES REMAIN
RATHER DRY RIGHT THROUGH THE DAY...WITH DEEPER MOISTURE AXIS REMAIN
TO OUR WEST. CAA DROPS H8 TEMPERATURES INTO THE MID SINGLE
DIGITS...MORE THAN COLD ENOUGH TO ENTICE A LAKE RESPONSE (GULP!).
THAT SAID...NOT REALLY ENTHUSED ABOUT LAKE POTENTIAL...WITH DEEP
MOISTURE REMAINING UPSTREAM AND RATHER WEAK/DISORGANIZED LOW LEVEL
WIND FIELDS. MAY SEE SOME POP-UP ACTIVITY DURING THE AFTERNOON WITH
LAND MASS DESTABILIZATION...ESPECIALLY IF THE MORE AGGRESSIVE
NAM-WRF DEPICTIONS ARE REALIZED. HAVE TRENDED FORECAST HEAVILY IN
THIS DIRECTION...FOCUSING "BEST" SHOWER POTENTIAL TO
CLIMATOLOGICALLY FAVORED NORTHEAST LOWER WHERE LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED. THUNDER THREAT NOT INCLUDED...DISCOUNTING THE NAM
AT THIS TIME. LESS SHOWER ACTIVITY LIKELY TO RESULT IN SLIGHTLY WARMER
TEMPERATURES. HAVE NUDGED READINGS UP A FEW DEGREES ACROSS THE
BOARD...BUT NO DOUBT TEMPERATURES WILL BE SEVERAL DEGREES BELOW LATE
JULY NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
A RATHER BLOCKED LOOK REMAINS TO THE OVERALL HEMISPHERIC
PATTERN...WITH REX BLOCKING FOUND OVER THE NORTH CENTRAL
PACIFIC...AND A LARGE RIDGE OF HIGH PRESSURE FOUND AROUND IN THE
NORTH ATLANTIC /40W/. IN BETWEEN WE ARE LEFT WITH MEAN TROUGHING
OVER THE GREAT LAKES...WITH A VIGOROUS SHORTWAVE SEEN ON WATER VAPOR
IMAGERY DROPPING INTO THE UPPER MISSISSIPPI VALLEY THAT WILL HAVE
IMPLICATIONS FOR OUR WEEKEND WEATHER. LOOKING AHEAD...THE PATTERN
APPEARS TO BE VERY SLOW TO BREAK DOWN OVER THE NEXT SEVERAL
DAYS...WITH NORTH ATLANTIC HIGH PROGGED TO ACTUALLY RETROGRADE A BIT
BY EARLY NEXT WEEK...BEFORE SLOWLY BREAKING DOWN AND BECOMING
INCREASINGLY PROGRESSIVE LATER NEXT WEEK. THIS IDEA IS REFLECTED IN
THE LATEST NAO ENSEMBLE FORECASTS...MAINTAINING AN OVERALL NEGATIVE
PHASE/BLOCKED/COOLISH PATTERN UNTIL THE BEGINNING OF AUGUST BEFORE
TRENDING MORE NEUTRAL.
SATURDAY NIGHT INTO SUNDAY...MIGHT AS WELL RIP THE JULY AND AUGUST
PAGE RIGHT OFF THE CALENDAR...AS PATTERN FOR THE WEEKEND WILL BE
NOTHING SHORT OF FALL-LIKE. FIRST OFF..APPROACHING SHORT WAVE IS
SCHEDULED TO DROP INTO THE GREAT LAKES AND BECOME CLOSED OFF BY
SUNDAY AS A 555 DM LOW /YIKES!/. THE 500 MB HEIGHT ANOMALY IS AROUND
3 SD BELOW NORMAL FOR THIS TIME OF YEAR PER GEFS STANDARDIZED
ANOMALIES. CORE OF COLDEST AIR LOOKS TO PASS DIRECTLY OVER THE
CWA...WITH H85 TEMPS FALLING AOB 5C DURING THE DAY SUNDAY. BASED
ON PATTERN RECOGNITION AND ABUNDANCE OF H85-H7 MOISTURE PRESENT
DURING THE DAY ON SUNDAY...LOOKING LIKE A PRIME SETUP FOR SOME
INSTABILITY SHOWERS...ESPECIALLY DURING THE AFTERNOON IF WE CAN GET
JUST ENOUGH INSOLATION...DESPITE OVERALL CLOUDY LOOK TO THE
FORECAST. IN ADDITION...ANY SUBTLE VORT MAX ROUNDING MAIN LOW WILL
ALSO CREATE A THREAT FOR SHOWERS. REMOVED THUNDER FROM THE FORECAST
FOR INLAND SPOTS AS I AM NOT CONFIDENT THAT WE WILL HAVE SUFFICIENT
LAPSE RATES AND INSOLATION TO PRODUCE ANY APPRECIABLE CAPE AND
CONVECTIVE DEPTH TO PRODUCE THUNDER. COULD FORESEE SOME GRAUPEL
BEING MIXED GIVEN THE AMOUNT OF COLD AIR ALOFT...BUT TOO SOON TO
INCLUDE SUCH SMALL/MESOSCALE DETAILS IN THE FORECAST ATTM. HIGH
TEMPS ON SUNDAY WILL STRUGGLE TO BREAK THE 60 DEGREE MARK BASED ON
THIS VERY COOL PATTERN...AN KNOCKED OFF A DEGREE OR TWO FROM THE
INHERITED HIGH TEMPERATURES.
OF BIGGER CONCERN IS THE LAKE EFFECT RAIN POTENTIAL /YES...LAKE
EFFECT/...LAKE TEMPS IN THE MID TO UPPER 60S AND AFOREMENTIONED H85
TEMPS WILL CREATE DELTA T`S AROUND 13 TO 18C. THERE IS A DISCREPANCY
BETWEEN THE GUIDANCE OF THE MAIN 1000-850 MB FLOW SUNDAY
NIGHT...WITH THE GFS SUGGESTING MORE OF A SOUTHERLY FLOW FOR NW
LOWER...BUT THE CONSENSUS OFF THE NAM/GEM/ECMWF IS FOR A WEST TO
NORTHWEST ONSHORE WIND DIRECTION...ALBEIT FAIRLY LIGHT. WOULD NOT BE
SURPRISED TO SEE SOME LAKE EFFECT THUNDER WITH LAKE-INDUCED CAPE
VALUES HOVERING AROUND 750 J/KG BASED OFF NAM AND SREF BUFKIT
SOUNDINGS...AND LEFT SLT CHC THUNDER FOR LAKE EFFECT REGIONS THROUGH
SUNDAY. GIVEN THE STRONG INSTABILITY OVER THE LAKES WITH THE UPPER
LOW...ALSO LOOKING LAKE A GOOD SETUP FOR WATERSPOUTS OVER ALL OF THE
GREAT LAKES THROUGH SUNDAY.
SUNDAY NIGHT INTO MONDAY...THE UPPER LOW WILL BE SLOW TO MOVE OFF TO
THE EAST...ALONG WITH THE CORE OF DEEPEST MOISTURE AND BEST FORCING.
DELTA T`S WILL STILL REMAIN FAVORABLE FOR SOME LAKE EFFECT RAIN
SHOWERS FOR NORTHWEST LOWER...ALONG WITH WATERSPOUTS FOR THE GREAT
LAKES THROUGH SUNDAY NIGHT. DRIER MID LEVEL AIR WILL FILTER IN LATE
SUNDAY NIGHT INTO MONDAY...ALONG WITH WEAK SURFACE HIGH PRESSURE
SETTLING INTO THE WESTERN GREAT LAKES. SKIES WILL GRADUALLY CLEAR
FROM WEST TO EAST MONDAY...WITH HIGH TEMPERATURES EXPECTED TO
REBOUND INTO THE MIDDLE 60S TO NEAR 70...ASSUMING SUFFICIENT
SUNSHINE BY AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...CUTOFF LOW PROGGED TO BE CLEAR OF THE
REGION BY MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN THE GREAT
LAKES THROUGH TUESDAY NIGHT. SHORT WAVE RIDGING IS EXPECTED TO
SETTLE IN OVERHEAD UNDER A WEST NORTHWEST UPPER LEVEL FLOW REGIME.
THE REGION SHOULD SEE A GOOD DEAL OF SUNSHINE...WITH NEAR TO
SLIGHTLY BELOW NORMAL READINGS FOR TUESDAY ALONG WITH SOME COOL
NIGHTS EXPECTED MONDAY AND TUESDAY NIGHT. THE NEXT SHORTWAVE IN THE
WNW FLOW REGIME DROPS INTO THE GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY...AND THE ASSOCIATED LOW MOVING THROUGH SOUTHERN ONTARIO
WILL DRAG A COLD FRONT THROUGH THE CWA DURING THIS TIMEFRAME. THIS
WILL PROVIDE THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
REGION. A SECONDARY STRONGER SHORT WAVE LOOKS TO FOLLOW QUICK ON ITS
HEELS BY FRIDAY. ECMWF/GFS DIFFER ON THE TIMING AND PLACEMENT OF THE
SECOND WAVE...WITH THE NEW 12Z ECMWF SLOWER AND FURTHER NORTH WITH
THE WAVE. WILL HOLD OFF ADDING POPS FOR FRIDAY FOR NOW...AS I DON`T
WANT TO CLUTTER UP THE EXTENDED TOO MUCH WITH AN ALREADY FAIRLY BUSY
WEATHER PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 132 AM EDT SAT JUL 27 2013
SUMMARY: A COLD FRONT WILL PUSH THROUGH THE TERMINALS OVERNIGHT
TAKING ANY REMAINING SHOWER ACTIVITY AND PUSHING IT EAST. LOW
PRESSURE WILL REMAIN OVER NORTHERN MICHIGAN THROUGH SATURDAY...
HOWEVER...WITH LOW CLOUDS EXPECTED THROUGH THE DAY ALONG WITH A FEW
AFTERNOON SHOWERS.
RESTRICTIONS: CONDITIONS HAVE DETERIORATED TO IFR/MVFR OVER THE PAST
FEW HOURS...AND EXPECT A LITTLE MORE DETERIORATION THROUGH THE
PRE-DAWN HOURS. THIS SHOULD GIVE MBL/TVC/PLN ALL A PERIOD OF IFR
CIGS...WITH LOW MVFR EXPECTED TO HOLD ON AT APN. GRADUAL
IMPROVEMENT IS EXPECTED DURING THE DAY ON SATURDAY WITH VFR
RETURNING TO MBL/TVC/PLN BY AFTERNOON. THERE REMAINS SOME QUESTION
AS TO THE POTENTIAL FOR A SECONDARY LOW PRESSURE SYSTEM TO SPREAD
RAIN BACK TOWARDS APN IN THE AFTERNOON...AND AS SUCH WILL DELAY
IMPROVEMENT TO VFR HERE UNTIL SATURDAY EVENING.
WINDS: WINDS WILL BECOME LIGHT NORTHWEST OVERNIGHT...STRENGTHENING
TO 5-10KTS FOR THE DAY ON SATURDAY BEFORE DIMINISHING TO 5KTS OR
LESS AGAIN SATURDAY EVENING.
&&
.MARINE...
ISSUED AT 415 PM EDT FRI JUL 26 2013
MARINE...GUSTY PRE-FRONTAL SOUTHWEST WINDS TO CONTINUE THROUGH THIS
AFTERNOON...MAINLY IMPACTING NORTHERN LAKE MICHIGAN. PRESSURE
GRADIENT SLACKENS OVERNIGHT...DESPITE COLD FRONTAL PASSAGE. GUSTY
THUNDERSTORM WINDS EXPECTED ALONG THIS FRONT...ESPECIALLY THIS
EVENING. MAINLY LIGHT WEST WINDS EXPECTED THROUGH THIS WEEKEND.
WATERSPOUT POTENTIAL WILL BE ON THE INCREASE THIS WEEKEND AS
UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE SLOWLY ROTATES ACROSS
THE NORTHERN LAKES. PERIODIC SHOWERS ALSO EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...NS
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
313 AM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
TODAY...PER UNR UA SOUNDING AND THE RAP AND NAM MODELS...IT LOOKS
LIKE THERE IS A MOIST AND MODESTLY UNSTABLE EML OPERATING ACROSS THE
FCST AREA. THE NAM...RAP...HRRR AND GEMREG MODELS SEEM TO HAVE A
HANDLE ON THIS DISTURBANCE WITH DIFFERENCES IN THE LOCATION OF THE
RAINFALL. THE CONSENSUS IS FOR THE STORMS ACROSS WRN AND SWRN NEB TO
DECAY OR MOVE OUT OF THE FCST AREA EARLY THIS MORNING WHILE THE
SECOND BAND ACROSS NCNTL NEB CONTINUES TO OPERATE THROUGHOUT THE
MORNING AND THEN DECAYS DURING THE AFTERNOON.
SPC PUBLISHED THIS DISCUSSION AT 742Z...MODERATE MIDLEVEL WAA AND
FRONTOGENESIS IS LOCATED OVER WRN/CNTRL NEB THIS MORNING. IN
ADDITION...A PLUME OF MOISTURE AT 600-700 MB AND STEEP MIDLEVEL
LAPSE RATES IS YIELDING MODERATE MUCAPE VALUES UPWARDS OF 1000 J/KG.
THIS BUOYANCY COMBINED WITH THE ZONE OF FOCUSED MESOSCALE ASCENT IS
RESULTING IN SCATTERED THUNDERSTORM DEVELOPMENT OVER THE AREA. IN
ADDITION...A 60 KT MIDLEVEL NNWLY JET IS CONTRIBUTING TO STRONG
EFFECTIVE BULK SHEAR ON THE ORDER OF 40-60 KT...WHICH IS SUPPORTIVE
OF ELEVATED SUPERCELL DEVELOPMENT. THIS ENVIRONMENT MAY RESULT IN
ISOLATED INSTANCES OF LARGE HAIL DURING THE MORNING...BUT THE THREAT
IS TOO MARGINAL FOR A WW.
TONIGHT...SOME MODEL SOLNS...THE NAM IN PARTICULAR...SUGGEST ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SWRN
NEB. THE GEMREG IS FARTHER SOUTH HOLDS THE QPF ACROSS KS.
THIS WEATHER SHOULD BE GENERATED BY A DISTURBANCE...CURRENTLY ACROSS
WRN MT...WHICH WILL DROP SOUTH THROUGH THE NW FLOW AND MAINLY AFFECT
THE CNTL HIGH PLAINS BUT THE NAM SHOWS A BURST OF CONVECTION FIRING
ACROSS SWRN NEB. GIVEN THE NORTHWEST FLOW UNDERWAY AND THE APPARENT
FERTILE ENVIRONMENT FOR RAINFALL...THE NAM IS A CREDIBLE SOLN. SO
TSTMS ARE POSSIBLE TONIGHT...MAINLY SOUTH OF INTERSTATE 80.
HIGH TEMPS TODAY SHOULD REMAIN IN THE 70S WITH THE COOL SPOT ACROSS
CUSTER COUNTY...NEAR 70 FOR A HIGH THERE. LOWS TONIGHT IN THE 40S
AND 50S LOOK REASONABLE GIVEN THE COOL HIGH ACROSS SRN MANITOBA AND
BACKED SFC WINDS TUGGING ON THE COOL AIR FROM THE NORTH.
.LONG TERM...
.SUNDAY THROUGH MONDAY...
A FAIRLY COOL PERIOD STARTS THE WEEK AS MODELS ARE IN GOOD AGREEMENT
FOR A SLOW TRANSITION TO A FAIRLY ACTIVE AND WET START OF THE
WEEK. SEVERAL BOUNDARIES WILL COME INTO PLAY AS MOISTURE POOLS
ACROSS THE WEST IN A PREVAILING UPSLOPE PATTERN. A FRONTAL
BOUNDARY WILL EXTEND SOUTH ON THE HIGH PLAINS...WHILE SURFACE
RIDGING REACHES FROM THE NORTHERN MIDWEST THROUGH THE OHIO VALLEY.
AT THIS TIME MONDAY EVENING APPEARS A GOOD SHOT FOR SEVERE
THUNDERSTORM DEVELOPMENT AS THE UPPER RIDGE AXIS WEAKENS AND
EMBEDDED WAVES MOVE EAST IN THE EVENING. IF ALL PANS OUT GOOD
INSTABILITY EXTENDS THROUGH THE FAR NORTHWEST SANDHILLS THAT WOULD
PROVIDE THE ENVIRONMENT FOR SEVERE STORMS MONDAY NIGHT. CONSIDERABLE
CLOUD COVERAGE WILL HELP KEEP TEMPERATURES DOWN AS WELL WITH HIGHS
MAINLY IN 70S... COMPARED TO NORMALS THAT WOULD BE CLOSER TO THE
UPPER 80S.
.TUESDAY THROUGH SATURDAY...
THE PATTERN REMAINS OVERALL PROGRESSIVE WITH SURFACE BOUNDARIES IN
PLACE FOR A CONTINUED CHANCE FOR DAILY THUNDERSTORM ACTIVITY. AS THE
FLOW BECOMES MORE ZONAL TEMPERATURES WILL TREND TOWARD NORMAL BY MIDWEEK.
THE EMBEDDED WAVES CREATE CHALLENGES AS TO THE AREAL COVERAGE OF
STORMS. THE UPPER RIDGE STRENGTHENS ACROSS THE INTERMOUNTAIN
REGION THROUGH MIDWEEK THEN WEAKENS AS THE NEXT UPPER LOW MOVES
INTO THE NORTHEAST PACIFIC. THE RISING HEIGHTS MIDWEEK WILL HELP
SHIFT THE BETTER CHANCE FOR RAIN NORTH UNTIL THE APPROACH OF THE
WEEKEND. TEMPERATURES REBOUND IN THE FAR WEST TUESDAY...ALTHOUGH
IF MODELS SLOW DOWN TEMPERATURES MAY STRUGGLE TO REACH THE 80S.
FOR NOW TRENDED TEMPERATURES UP BEYOND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM CDT SAT JUL 27 2013
SHORT RANGE FORECASTS PROJECT THE DEVELOPMENT OF SHOWERS OR
THUNDERSTORMS DEVELOPING 06Z-08Z IN CENTRAL AND NORTH CENTRAL
NEBRASKA TONIGHT. THE SHORT RANGE PROJECTIONS INDICATE THAT THE
SHOWERS/THUNDERSTORMS WILL DEVELOP NORTH AND EAST OF A VTN-MHN-LBF
LINE AND THEY COULD CONTINUE INTO THE MORNING SATURDAY MAYBE TO 16Z.
SINCE VTN IS ON THE NORTHERN EDGE OF THE AREA AND LBF ON THE WESTERN
EDGE...THERE IS LITTLE CONFIDENCE THAT THEY WILL OCCUR AT THE LBF
AND VTN TERMINALS. FOR THE TIME BEING...THEN...WE WILL NOT INCLUDE
THUNDER IN THE TERMINAL FORECASTS FOR VTN AND LBF.
LAST NIGHT...THE EVENING SOUNDING SIGNALED THE POSSIBILITY OF FOG AS
IT HAD A UNIFORM MOISTURE BELOW 1000 FEET AGL WITH A SATURATION
TEMPERATURE OF 59. MIST FOG DID FORM WITH VISIBILITY BELOW 1SM.
TONIGHT...THE EVENING LBF SOUNDING ONCE AGAIN SHOWED UNIFORM
MOISTURE BELOW 1000 FEET AGL BUT THE INDICATED SATURATION
TEMPERATURE IS 47. LOW TEMPERATURES TONIGHT ARE EXPECTED TO REMAIN
WELL ABOVE THAT TEMPERATURE...BR/FG IS NOT LIKELY.
IN THE AREAS NOT AFFECTED BY THE SHOWERS/THUNDERSTORMS...NO
RESTRICTIONS TO FLIGHT OPERATIONS ARE EXPECTED.
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...KECK
AVIATION....CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
104 AM CDT SAT JUL 27 2013
.UPDATE...
ISSUED AT 1255 AM CDT SAT JUL 27 2013
LITTLE CHANGE TO THE GOING FORECAST. HAVE DROPPED SKY COVER
FORECAST TO ZERO WEST AND POPS TO ZERO ENTIRE FORECAST AREA.
RECORD LOW TEMPERATURES ARE STILL POSSIBLE AROUND
DAYBREAK...ESPECIALLY AT BISMARCK AND JAMESTOWN.
UPDATE ISSUED AT 947 PM CDT FRI JUL 26 2013
HIGH PRESSURE CONTINUES TO SETTLE ACROSS THE NORTHERN PLAINS THIS
EVENING GENERATING LIGHT WINDS AND CLEAR SKIES. TEMPERATURES ARE
STILL EXPECTED TO RADIATE TO RECORD LOWS (LOWER 40S) OVER BISMARCK
AND JAMESTOWN BY EARLY SATURDAY MORNING. SEE TABLE IN THE SHORT
TERM SECTION BELOW FOR FORECAST AND RECORD LOWS FOR OTHER SELECTED
CITIES IN WESTERN AND CENTRAL NORTH DAKOTA.
OTHERWISE...NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST.
THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 657 PM CDT FRI JUL 26 2013
NOT TOO MANY CHANGES WERE MADE TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
RECORD LOWS STILL LOOK TO BE ON TRACK FOR BISMARCK AND JAMESTOWN
TONIGHT. SEE TABLE IN THE SHORT TERM DISCUSSION BELOW FOR FORECAST
AND RECORD LOWS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
NO PRECIPITATION FOR THE SHORT TERM PERIOD...WITH THE MAIN
CHALLENGE BEING RECORD COLD TEMPERATURES FOR SATURDAY
MORNING...MAINLY FOR BISMARCK AND JAMESTOWN.
LATEST VISIBLE SATELLITE IMAGERY SHOWS SCT/BKN CUMULUS FIELD
COVERING ALL OF NORTH DAKOTA. CYCLONIC FLOW WITH AN UPSTREAM
SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN WILL MAINTAIN THE
CUMULUS FIELD THROUGH THE EVENING...AND AFTER SUNSET WILL SEE A
GRADUAL REDUCTION IN CLOUDS WITH CLEAR SKIES COMMENCING LATER
TONIGHT. THE SHORTWAVE IS EXPECTED TO MAKE IT TO AROUND STANLEY BY
00Z SATURDAY...THEN INTO THE JAMES RIVER VALLEY BY 06Z SATURDAY.
THE GFS AND TO SOME EXTENT THE RAP AND HRRR TRY TO DEVELOP A
COUPLE SHOWERS IN THE SOUTHWEST AND ALSO IN THE NORTHEAST/TURTLE
MOUNTAINS THIS AFTERNOON...BUT HAVE OPTED TO KEEP IT DRY WITH
REGIONAL RADAR AND SURFACE OBSERVATIONS CONTINUING TO SHOW A VOID
IN ANY PRECIPITATION DEVELOPMENT UP TO THIS POINT. A 1030MB
SURFACE HIGH PRESSURE OVER SOUTHEASTERN SASKATCHEWAN WILL ALSO
SHIFT SOUTHEAST INTO EAST CENTRAL NORTH DAKOTA...AND INTO THE
LOWER JAMES RIVER VALLEY BY 12Z SATURDAY. UPSTREAM LOW
TEMPERATURES IN SOUTH CENTRAL CANADA FRIDAY MORNING RANGED FROM
38F TO 42F...WHICH IS IN THE BALLPARK OF WHAT THE MET/MAV GUIDANCE
IS FOR CENTRAL NORTH DAKOTA. THE OLD RULE OF THUMB USING THE
MINIMUM DEWPOINT DURING THE MAX TEMPERATURE FOR OBTAINING AN
APPROXIMATE LOW TEMPERATURE ALSO SUPPORTS LOWS BETWEEN 39F AND
44F. CONFIDENCE IS HIGH FOR RECORD LOWS IN BISMARCK AND
JAMESTOWN...WITH MINOT...WILLISTON...AND DICKINSON COMING JUST SHY
OF ESTABLISHING NEW RECORD LOWS.
RECORD LOW TEMPERATURES FOR SATURDAY JULY 27 ARE AS FOLLOWS...
CITY RECORD LOW/DATE FORECAST LOW TEMP
BISMARCK 43F/1994 41F
JAMESTOWN 44F/1904 41F
MINOT 40F/1925 42F
WILLISTON 40F/1908 43F
DICKINSON 40F/1971 43F
CONSIDERING THE LOCATION OF THE SURFACE HIGH...EAST CENTRAL NORTH
DAKOTA AND INTO THE SOUTHERN JAMES RIVER VALLEY...THIS IS THE
OPTIMAL LOCATION FOR OBTAINING THE COLDEST TEMPERATURES ACROSS
SOUTH CENTRAL NORTH DAKOTA...BISMARCK AND JAMESTOWN. UPSTREAM
OBSERVATIONS IN SOUTH CENTRAL CANADA ALSO HAD SOME PATCHY FOG FRIDAY
MORNING AND HAVE ADDED THAT TO THE FORECAST...MAINLY ALONG AND
JUST EAST OF HIGHWAY 83.
FOR SATURDAY...SUNNY WEST...AND MOSTLY SUNNY SKIES CENTRAL.
EXPECT MID TO LATE MORNING CUMULUS AGAIN DEVELOPING OVER CENTRAL
NORTH DAKOTA WITH WEAK CYCLONIC FLOW...BUT SOUNDINGS SHOW DRY
AIR/SUBSIDENCE ALOFT WILL BECOME MUCH STRONGER..AND THIS WILL
INHIBIT ANY FURTHER BUILD UPS FOR THE AFTERNOON. THE RESULT WILL
BE A SCATTERED FAIR WEATHER CUMULUS FIELD EARLY ON...THEN
DISSIPATING THROUGH THE AFTERNOON. AFTERNOON HIGHS AROUND 70F
CENTRAL TO THE MID 70S WEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
WE TRANSITION FROM A COOL AND DRY PERIOD BACK TO A WARMER AND
ACTIVE PERIOD FOR THE BEGINNING OF THE LONG TERM PERIOD.
AFTERWARDS...A RETURN TO A RELATIVELY QUIET PERIOD IS EXPECTED
THROUGH THE MIDDLE PORTIONS OF THE WORK WEEK UNTIL LATER NEXT WEEK
WHEN WE MAY SEE INCREASING CHANCES FOR MORE WIDESPREAD
PRECIPITATION.
RETURN FLOW INCREASES OVER WESTERN NORTH DAKOTA SATURDAY NIGHT AS
SURFACE HIGH PRESSURE SLOWLY MOVES EAST TOWARDS THE UPPER
MISSISSIPPI VALLEY...AND A SFC TROUGH DEVELOPS IN THE LEE OF THE
MONTANA ROCKIES AHEAD OF A LONG WAVE TROUGH MOVING INTO ALBERTA.
LATEST 12Z MODELS HAVE AGAIN SLOWED DOWN THE EASTWARD PROGRESSION
OF THE SURFACE TROUGH OVER EASTERN MONTANA...AND NOW KEEP ALL
PRECIPITATION OFF TO OUR WEST THROUGH SUNDAY MORNING. AS A RESULT
I HAVE REMOVED ALL MENTION OF THUNDERSTORMS THROUGH 18Z SUNDAY.
SHORT WAVE MID LEVEL RIDGE MOVING ACROSS THE REGION ON SUNDAY WILL
BRING WARMER AIR TO WEST AND CENTRAL NORTH DAKOTA...WITH DAYTIME
HIGHS WARMING BACK TOWARDS THE 80 DEGREE MARK WEST AND MID TO
UPPER 70S CENTRAL. WE START TO SEE INCREASING INSTABILITY OVER THE
FAR WESTERN COUNTIES SUNDAY AFTERNOON AS RETURN FLOW CONTINUES
HELPING LOW LEVEL MOISTURE MOVE BACK INTO THE NORTHERN PLAINS.
WHILE I HAVE KEPT SOME MENTION FOR AFTERNOON CONVECTION IN THE
FORECAST ACROSS THE WEST...12Z NAM/GFS BUFFER SOUNDINGS INDICATE
WE WILL BE STRONGLY CAPPED SO WILL CONSIDER TRENDING SUNDAY
AFTERNOON DRY WITH FUTURE FORECAST PACKAGES.
AS THE RIDGE CONTINUES EASTWARD...FLOW ALOFT WILL TRANSITION TO MORE
WEST/SOUTHWESTERLY SUNDAY NIGHT THROUGH MONDAY AND INTO MONDAY NIGHT
ALONG WITH FAVORABLY INSTABILITY FOR THUNDERSTORMS SPREADING ACROSS
THE STATE. COMBINED WITH THE SURFACE TROUGH PUSHING EAST ACROSS THE
DAKOTAS...EXPECT TO SEE A RATHER ACTIVE CONVECTIVE PERIOD FROM
LATE SUNDAY NIGHT THROUGH MONDAY EVENING. AS FAR AS SEVERE
WEATHER...LINGERING CLOUDS FROM SUNDAY NIGHTS EXPECTED CONVECTION
COULD VERY WELL LIMIT THE SEVERE POTENTIAL...FOR MONDAY.
HOWEVER...LATEST MODELS ARE NOW INCREASING THE POTENTIAL FOR
SCATTERED STRONG TO SEVERE STORMS...ESPECIALLY MONDAY
AFTERNOON/EVENING. WILL MENTION THIS POSSIBILITY IN THE HWO. IT
SHOULD BE NOTED THE 12Z NAM...WHILE A FAST OUTLIER...WOULD FAVOR
THE MOST ACTIVE PERIOD LATE SUNDAY EVENING THROUGH MONDAY
AFTERNOON. THUS WILL NEED TO KEEP AN EYE ON THE MODEL TRENDS THE
NEXT FEW PERIODS.
AFTER THIS SHORT PERIOD OF ACTIVE WEATHER...MODELS FORECAST A RETURN
TO A QUIETER WEATHER PERIOD TUESDAY INTO MID-WEEK WITH NORTHWEST
FLOW ALOFT REDEVELOPING FOLLOWED BY ANOTHER S/WV RIDGE. WHILE CANNOT
RULE OUT ISOLATED SHOWERS/THUNDERSTORMS...THE OVERALL PATTERN
TUESDAY-THURSDAY WOULD NOT SUPPORT WIDESPREAD PRECIPITATION. AS WE
PROCEED TOWARDS THE END OF THE WORK WEEK INTO THE FOLLOWING
WEEKEND...BOTH THE 12Z GFS/ECMWF DEPICT ANOTHER ACTIVE WEATHER
PERIOD DEVELOPING AS FLOW BECOMES QUASI-ZONAL AGAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY) ISSUED AT 1255
AM CDT SAT JUL 27 2013
VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. A FEW TO SCATTERED
CLOUDS COULD WORK INTO KMOT AND KJMS BEFORE DAYBREAK. WINDS WILL
CONTINUE TO GRADUALLY VEER TO EASTERLY/SOUTHEASTERLY THROUGH THE
PERIOD AS HIGH PRESSURE CRESTS ACROSS THE REGION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...KS
LONG TERM...NH
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
421 AM EDT SAT JUL 27 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH EAST ACROSS THE REGION THROUGH
TONIGHT. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE OHIO VALLEY
ON SUNDAY WHILE AN UPPER LEVEL LOW SPINS ACROSS THE GREAT LAKES.
THE UPPER LEVEL LOW WILL MOVE SLOWLY NORTHEAST THROUGH MONDAY
WHILE THE SURFACE HIGH EXPANDS ACROSS AREA. TEMPERATURES WILL BE
BELOW NORMAL THROUGH THE BEGINNING OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN GREAT AGREEMENT THIS MORNING. HAVE USED THE RAP AND
HRRR FOR TIMING OF PCPN.
AS WAS ADVERTISED YESTERDAY...A PIECE OF ENERGY IS BEING DRAWN NE
ACRS THE OHIO VALLEY THIS MORNING WHILE AN UPR LVL CLOSED LOW SLOWLY
ROTATES SOUTHWARD ACRS THE WRN GREAT LAKES. THIS ENERGY WILL
COMBINE WITH SOME LOW TO MID LVL FORCING OUT AHEAD OF A COLD
FRONT TO BRING WIDESPREAD SHOWERS TO MUCH OF THE REGION DURING THE
MORNING HOURS. INSTABILITY IS WEAK ENOUGH THAT THUNDER IS NOT
ANTICIPATED. FOR THIS AFTERNOON...THE COLD FRONT WILL PUSH EAST
INTO THE WRN CWFA WHILE WIDESPREAD PCPN PUSHES TO THE EAST. THERE
COULD BE A GAP BETWEEN DEVELOPMENTAL PCPN ALONG/AHEAD OF THE FRONT
VERSUS DEPARTING WIDESPREAD PCPN. WE SHOULD SEE ENOUGH DAYTIME
HEATING TO ALLOW FOR A LITTLE MORE INSTABILITY THIS AFTN FOR A
MENTION OF THUNDER. GIVEN PWATS OF 1.75 INCHES...SOME OF THE
SHOWERS MAY BE MODERATE TO LOCALLY HEAVY.
CLOUDS AND PCPN WILL HOLD TEMPERATURES DOWN. HIGHS IN THE LOWER TO
MID 70S STILL LOOK REASONABLE WHICH ARE ABOUT 10 DEGREES BELOW
NORMAL FOR LATE JULY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
S/WV ENERGY ROTATING SE INTO THE REGION AROUND UPR LVL CLOSED LOW
WILL PUSH THE COLD FRONT EAST OF THE AREA OVERNIGHT. THE THREAT OF
SHOWERS/ISOLATED STORMS WILL COME TO AN END THIS EVENING THROUGH
EARLY MORNING...FOLLOWED BY SOME CLEARING IN THE DRY SLOT BEHIND
THE FRONT. MODELS CONTINUE TO ADVERTISE SOME COOL AIR OVERNIGHT...
ESPECIALLY WEST WHERE DRIER AIR AND BETTER CLEARING WILL OCCUR.
RECORD LOWS TONIGHT ARE 50 AT CMH...54 AT DAY AND 53 AT CVG. DAY
AND CVG HAVE THE BEST CHANCE OF EITHER TYING OR BREAKING THEIR
RECORD LOWS. WILL RANGE LOWS FROM NEAR 50 WEST TO THE UPPER 50S
EAST.
UPR LVL CLOSED LOW WILL MOVE SLOWLY EAST ACRS THE WRN/CNTRL GREAT
LAKES AREA ON SUNDAY WHILE A RIDGE OF HIGH PRESSURE BUILDS INTO
THE OHIO VALLEY. CAA IN THE WAKE OF THE FRONT WILL RESULT IN SOME
SCT-BKN CUMULUS CLOUDS. CLOUDS SHOULD BE MOST NUMEROUS ACRS THE
FAR NW WHERE EMBEDDED S/WV ENERGY ROTATING AROUND THE LOW COMBINED
WITH WEAK DIURNAL INSTABILITY MAY RESULT IN A FEW SPOTTY SHOWERS
DURING THE AFTN AND EARLY EVENING. HIGHS ON SUNDAY WILL BE UNSEASONABLY
COOL RANGING FROM THE LOWER TO MID 70S. THESE VALUES WILL BE CLOSE
TO RECORD LOW MAXES FOR THE DATE.
FOR SUNDAY NIGHT INTO MONDAY...MOSTLY CLEAR NIGHT/MOSTLY SUNNY
DAY AS HIGH PRESSURE EXPANDS ACRS THE REGION WHILE UPR LVL CLOSED
LOW MOVES OFF TO THE EAST. TEMPERATURES WILL MODIFY SLIGHTLY INTO
THE MID AND UPPER 70S.
FOR THE PERIOD MONDAY NIGHT INTO TUESDAY NIGHT...HIGH PRESSURE
WILL MOVE EAST. MODELS SUGGEST THAT A SLOW MOVING LOW PRESSURE
SYSTEM WILL MOVE TOWARD THE OHIO VALLEY REGION FROM THE CNTRL/SRN
PLAINS. THE APPROACH OF THIS SYSTEM WILL BRING AN INCREASING
CHANCE FOR PCPN...MAINLY FOR LOCATIONS ALONG AND SOUTH OF THE OHIO
RIVER. OVERNIGHT LOWS WILL MODIFY WITH INCREASING CLOUDS. HIGHS
ON TUESDAY WILL RANGE FROM THE UPPER 70S TO AROUND 80 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
MODELS HAVE SLOWED ON AFOREMENTIONED LOW PRESSURE SYSTEM...SO PCPN
WILL LINGER INTO WEDNESDAY...MAINLY ALONG AND SOUTH OF THE OHIO
RIVER. ON THURSDAY...A SYSTEM EAST OF THE AREA WILL BRING A CHANCE
FOR SHOWERS AND THUNDERSTORMS TO EASTERN PORTIONS OF THE REGION.
BY THURSDAY NIGHT AND CONTINUING INTO FRIDAY...HIGH PRESSURE WILL
BRING DRY CONDITIONS BACK TO THE REGION. THERE WILL BE A SLIGHT
WARMING TREND IN TEMPERATURES THROUGH THE WEEK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
BROKEN MID LEVEL CLOUDS BETWEEN FL100-150 COVER THE AREA. BROKEN
TO OVERCAST LOW CLOUDS NEAR FL050 OVER EXTREME WESTERN AREA ARE
BEGINNING TO SPREAD EASTWARD. THESE LOW CLOUDS CONTAIN SHOWERS AND
PATCHES OF LIGHT RAIN IN ADVANCE OF THE COLD FRONT. SHOWERS ARE
FORECAST TO INCREASE IN INTENSITY AND COVERAGE INTO LATE MORNING.
THERE ARE SOME EARLY INDICATIONS THAT WE MAY SEE SOME CIGS FROM
KCVG TO KDAY DIP BELOW FL010 MID TO LATE MORNING FOR AN HOUR OR TWO.
WE WILL MONITOR THE SITUATION AND UPDATE THE FORECASTS IF OUR
CONFIDENCE INCREASES. THESE LOWER CIGS WOULD BE ASSOCIATED WITH
THE PERSISTENT RAIN AND HEAVY SHOWER ACTIVITY.
WITH THE EXCEPTION OF THE ABOVE MENTION IFR CONDS WE ARE EXPECTING
WIDESPREAD MVFR CONDS IN THE PCPN THIS MORNING WITH ONLY A BRIEF
LOWERING TO IFR IN VSBY IN SOME OF THE HEAVIEST SHOWERS. THIS PERIOD
OF PCPN SHOULD END AROUND NOON. AT THAT TIME THE MAIN THREAT WILL
BE THE POTENTIAL FOR WIDELY SCATTERED THUNDERSTORMS TO DEVELOPING
ALONG THE COLD FRONT AS IT MOVES EAST SOUTHEASTWARD ACROSS THE AREA
THIS AFTERNOON AND EVENING.
BEHIND THE FRONT LOW LEVEL DRY AIR WILL BEGIN TO PUSH IN CAUSING
THE LOW CLOUDS TO DISSIPATE. HOWEVER, MID LEVEL MOISTURE IS
EXPECTED TO BE SLOW TO RETREAT FROM THE AREA SO MID LEVEL CLOUDS
ARE CURRENTLY EXPECTED TO PERSIST THROUGH MOST OF THE NIGHTTIME
HOURS.
IN ADVANCE OF THE FRONT SURFACES WINDS WILL BE SOUTHWEST 5-12KT
BECOMING NORTHWEST AROUND 10KT BEHIND THE FRONT.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS MEDFORD OR
934 PM PDT FRI JUL 26 2013
.DISCUSSION...EVENING UPDATE. THUNDERSTORMS CONTINUE TO DIMINISH
ACROSS THE REGION WITH THUNDERSTORMS REMAINING IN ROUGHLY A MEDICINE
LAKE TO PAISLEY LINE AND TO THE SE. CURRENT FORECAST HAS THIS AND
WILL NOT UPDATE THIS EVENING.
ANOTHER HOT DAY IS OCCURRING ACROSS THE AREA...THOUGH
TEMPERATURES HAVE COOLED A BIT...ABOUT 5 DEGREES COOLER THAN
YESTERDAY. INSTABILITY AND AMPLE UPPER MOISTURE IS HELPING TO
GENERATE THUNDERSTORMS EAST OF THE CASCADES AND OVER NORTHERN
CALIFORNIA. THE AREAS EXPECTED TO GET THE MOST THUNDERSTORM
ACTIVITY ARE MODOC AND LAKE COUNTIES...WITH THE HRRR SHORT-RANGE
GUIDANCE AND OBSERVED LIGHTNING STRIKES SUPPORTING THIS. A RED
FLAG WARNING AT RFW HAS BEEN ISSUED FOR LAKE...EASTERN MODOC...AND
EXTREME EASTERN KLAMATH COUNTIES. WEST OF THE CASCADES CONVECTIVE
INHIBITION...AS IS SHOWN IN FORECAST SOUNDINGS AND IN THE CURRENT
CLOUD DEVELOPMENT WHICH IS LIMITED IN VERTICAL DEVELOPMENT.
A COOLDOWN AND TRANSITION TOWARD NORMAL OR JUST BELOW NORMAL
TEMPERATURES WILL BE UNDERWAY TONIGHT INTO NEXT WEEK. TOMORROW THERE
IS ONE MORE CHANCE OF THUNDERSTORMS OVER NORTHERN CALIFORNIA WITH
LINGERING INSTABILITY THERE. ELSEWHERE...WESTERLIES AND STABLE
CONDITIONS WILL PREVENT THUNDERSTORM ACTIVITY. THE MARINE LAYER
WILL DEEPEN AND SEND CLOUDS FURTHER INLAND OVER THE NEXT COUPLE
MORNINGS...REACHING ROSEBURG BY SUNDAY MORNING. FOG WILL BEGIN TO
SUBSIDE AT THE COAST AS THE MARINE LAYER DEEPENS AND CLOUD BASES
RISE SOME...WITH DRIZZLE.
DRY AND COOL WEATHER WILL CONTINUE THROUGH EARLY NEXT WEEK...AND BY
WEDNESDAY MORNING DRIZZLE MAY AFFECT THE NORTH COAST AREA AROUND
NORTH BEND. THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME AND HAVE
KEPT THEM OUT OF THE EXTENDED PORTION OF THE FORECAST...WITH
SOUTHWEST AND WEST FLOW ALOFT...SIGNALING A CONTINUING STABLE AIR
MASS.
&&
.AVIATION...MARINE STRATUS HAS CLEARED FROM THE COASTAL AREAS
THIS MORNING...BUT LOW CLOUDS WILL RETURN TO THE SAME AREAS OF
COOS AND WESTERN DOUGLAS COUNTY AROUND 03Z THIS
EVENING...PERSISTING INTO SATURDAY MORNING. INLAND...VFR IS
EXPECTED OVER THE NEXT 24 HOURS. THUNDERSTORMS WILL CONTINUE THIS
AFTERNOON AND EVENING FROM NORTHERN CALIFORNIA NORTHEASTWARD INTO
KLAMATH AND LAKE COUNTIES. GUSTY AND VARIABLE WINDS WILL ACCOMPANY
THUNDERSTORMS.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ORZ030.
RED FLAG WARNING UNTIL 8 PM PDT SATURDAY FOR ORZ031.
CA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM
PDT SATURDAY FOR
PZZ356.
GALE WARNING FROM 11 AM TO 8 PM PDT SATURDAY FOR PZZ356.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SUNDAY FOR
PZZ350-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SUNDAY
FOR PZZ350.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SUNDAY FOR PZZ370.
GALE WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ376.
HAZARDOUS SEAS WARNING UNTIL 11 AM PDT MONDAY FOR PZZ376.
$$
NSK/NSK/BPN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
222 AM EDT SAT JUL 27 2013
.SYNOPSIS...
PRECIPITATION CHANCES WILL REMAIN IN THE FORECAST THROUGH THE
WEEKEND AS A SERIES OF UPPER LEVEL DISTURBANCES AND A COLD FRONT
PASS THROUGH. CONDITIONS LOOK TO IMPROVE SLIGHTLY FOR THE START OF
NEXT WEEK AS SURFACE HIGH PRESSURE BUILDS WHILE REDUCING CHANCES FOR
PRECIPITATION.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE INCREASING
OVER THE NC FOOTHILLS AND PORTIONS OF UPSTATE SC IN RESPONSE TO
INCREASING UPSLOPE FLOW AND PVA OVER THE REGION. POPS WERE INCREASED
ACCORDINGLY AND EXPECT THE COVERAGE OF PRECIP TO INCREASE THROUGH
THE OVERNIGHT HOURS. SO FAR...NONE OF STORMS HAVE REACHED SEVERE
LEVEL DUE TO LIMITED BUOYANCY. THE MAIN THREAT FROM THESE STORMS
WILL BE HEAVY RAINFALL AND LOCALIZED FLOODING.
AS OF 945 PM EDT FRIDAY...SHOWERS AND THUNDERSTORMS ARE GRADUALLY
INCREASING OVER NE GA...THE WRN UPSTATE AND THE CENTRAL AND SW NC
MTNS. THIS IS GENERALLY WHAT WAS EXPECTED...THOUGH IT/S A FEW HOURS
EARLIER THAN EXPECTED. I SUSPECT THAT THIS CONVECTION WILL CONTINUE
TO SLOWLY MOVE NORTHEAST THE REST OF THE NIGHT...AND IT/S POSSIBLE
THAT MORE WILL DEVELOP ALONG THE BLUE RIDGE AS THE LLVL FLOW
INCREASES LATE. THE STRENGTHENING WINDS WILL BE IN RESPONSE TO AN
APPROACHING SHORT WAVE WHICH SHOWS UP WELL ON THE RUC H5 ANALYSIS
AND THE WATER VAPOR IMAGERY PRETTY MUCH RIGHT OVER THE MISSISSIPPI
RIVER ATTM. LOCALLY HEAVY RAIN AND EVEN A SEVERE STORM ARE TWO STILL
LOOK LIKE A GOOD BET.
AS OF 600 PM EDT FRIDAY...UPPED POPS INTO THE LIKELY CATEGORY ACROSS
A BROAD SECTION OF THE CENTRAL PART OF THE FA LATER TONIGHT. MOST OF
THE CONVECTIVE ALLOWING MODELS DEVELOP SHOWERS AND THUNDERSTORMS
LATER TONIGHT AS THE LLVL FLOW INCREASES TO 20 TO 25 KTS AND A
RATHER POTENT SHORT WAVE APPROACHES FROM THE BEST. IT APPEARS THAT
RAIN CHANCES WILL BE HIGHEST ACROSS THE BLUE RIDGE AND OUT INTO THE
FOOTHILLS WHERE UPSLOPE WILL AID ASCENT. LOCALLY VERY HEAVY RAIN IS
POSSIBLE WITH THE STORMS...WHICH HAS BASICALLY BEEN THE STORY OF THE
SUMMER. WITH DRY MID-LEVEL AIR...A FEW AREAS OF LARGE HAIL DAMAGING
STRAIGHT LINE WINDS WILL ALSO BE POSSIBLE...ESPECIALLY EARLY ON IN
THE EVENT...SAY BETWEEN 8 PM AND MIDNIGHT.
PREVIOUS DISCUSSION...ISOLATED DEEP CONVECTION CONTINUES TO DEVELOP
ACROSS THE FOOTHILLS AND THE UPPER SAVANNAH RIVER VALLEY. A LACK OF
TRULY ROBUST INSTABILITY (DUE TO WARM MID-LEVEL TEMPS) IS LIMITING
THE VERTICAL DEVELOPMENT OF THE CONVECTION...AND THERE HAS BEEN NO
LIGHTNING ACTIVITY OBSERVED THUS FAR (IN FACT...CELLS HAVE NOT EVEN
COME CLOSE TO BEING ENOUGH TO PRODUCE LIGHTNING). NEVERTHELESS...CU
IS BEGINNING TO APPEAR SOMEWHAT AGITATED OVER THE HIGH TERRAIN...AND
AS THE ATM CONTINUES TO HEAT UP...COVERAGE AND INTENSITY OF
CONVECTION SHOULD GRADUALLY INCREASE. WE WILL CONTINUE TO ADVERTISE
A GRADUAL INCREASE IN POPS TO LOW/SOLID CHANCE ACROSS THE WESTERN
HALF OF THE AREA BY LATE AFTERNOON...WHILE HOLDING ON TO SLIGHT
COVERAGE AT BEST IN THE WEAKER INSTABILITY ACROSS OUR EASTERN
PIEDMONT ZONES.
THE SHORT TERM MODELS CONTINUE TO PICK UP ON A WEAK VORT MAX...
POSSIBLY CONVECTIVELY INDUCED AND A PRECURSOR TO THE PRIMARY SHORT
WAVE CURRENTLY APPROACHING THE MISS VALLEY...MOVING ACROSS THE CWA
THIS EVENING INTO THE EARLY PART OF THE OVERNIGHT. IN RESPONSE...
MOST MODELS...INCLUDING THE HIRES MODELS...HINT AT INCREASING
COVERAGE OF CONVECTION TONIGHT. OUR CURRENT EXPECTATION IS THAT THIS
WAVE WILL SWEEP THE MORE ROBUST CONVECTIVE ACTIVITY CURRENTLY
DEVELOPING OVER CENTRAL GEORGIA ACROSS THE WESTERN HALF OF THE CWA
THIS EVENING...SO WILL GENERALLY FEATURE 40-50 POPS ACROSS MUCH OF
THE AREA DURING THIS TIME. SHEAR IS WEAK AND INSTABILITY COULD
CERTAINLY BE BETTER...BUT AN ISOLATED PULSE SEVERE STORM WILL BE
POSSIBLE ALONG WITH THE THREAT OF HEAVY RAIN THREAT.
TOMORROW MAY BE AN INTERESTING DAY AS THE PRIMARY VORT MAX
APPROACHES FROM THE TENN VALLEY. DEEP LAYER FLOW WILL STRENGTHEN IN
ADVANCE OF THIS FEATURE SUCH THAT SHEAR IS QUITE RESPECTABLE FOR
MID-SUMMER (20-25 KTS 0-3 KM...30-35 KTS 0-6 KM). THE PRIMARY
CONCERN WILL BE WITH THE DEGREE OF INSTABILITY...AS THE
STRENGTHENING S/SE FLOW SHOULD ALSO RESULT IN PLENTY OF MORNING
STRATOCU. NEVERTHELESS...MODEL SOUNDINGS DEPICT QUITE A BIT OF
LINGERING DRY MID-LEVEL AIR...SO WE COULD SEE ENOUGH HEATING TO
REALIZE CLOSE TO 2000 J/KG CAPE VALUES. IF SO...WE MAY WELL SEE AN
ORGANIZED SEVERE WEATHER THREAT. CONSIDERING THE UNCERTAINTY ABOUT
THE DEGREE OF HEATING...THE CURRENT SPC /SEE TEXT/5 PERCENT AREA
APPEARS REASONABLE FOR DAY 2.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRI...NUMEROUS SHOWERS/THUNDERSTORMS SHOULD BE ON
GOING SAT EVENING OVER EASTERN SECTIONS...IN RESPONSE TO A VIGOROUS
VORT MAX MOVING THROUGH THE CAROLINAS. I EXPECT THAT THE MAIN BODY
OF SHOWERS/STORMS WILL MOVE EAST OF THE AREA BY MIDNIGHT.
HOWEVER...A WEAK COLD FRONT WILL SLIP SE TO THE LEE OF THE MOUNTAINS
BY DAYBREAK SUNDAY...SO WILL NEED TO HOLD ONTO SOME CHANCE POPS
OVERNIGHT FOR SOME UPSLOPE MOUNTAIN SHOWERS...AND PERHAPS SOME
SHOWERS AND THUNDERSTORMS INDUCED BY THE FRONT.
ON SUNDAY...THE FRONT WILL LINGER OVER THE REGION AS AN UPPER LOW
DIGS OVER THE GREAT LAKES. LOW LEVEL CONVERGENCE COMBINED WITH UPPER
DIFFLUENCE AND AFTERNOON CAPES PEAKING AROUND 1500J IN THE AFTERNOON
SHOULD BE ENOUGH FOR SCT TO NUMEROUS SHOWERS AND THUNDERSTORMS...
MOST NUMEROUS OVER EASTERN SECTIONS. SOME SHOWERS/STORMS COULD LINGER INTO
SUNDAY EVENING OVER THE EAST. HOWEVER...THE FRONT WILL FINALLY MOVE
EAST OF THE AREA OVERNIGHT WITH HIGH PRESSURE BUILDING IN FROM THE
WEST.
ON MONDAY...THE SURFACE HIGH IS FORECAST TO DOMINATE THE REGIONAL
WEATHER. THEREFORE...EXPECT A DRY DAY WITH MOSTLY CLEAR TO PARTLY
CLOUDY CONDITIONS. STAYED CLOSE TO CONSENSUS GUIDANCE FOR MOST GRID
FIELDS. MAX TEMPS WILL BE A COUPLE CATEGORIES BELOW AVERAGE ON
SUNDAY...WARMING TO ABOUT A CATEGORY BELOW AVERAGE MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...THE EXTENDED PERIOD BEGINS LATE MONDAY WITH
HIGH PRESSURE BUILDING IN OVER THE EAST COAST BEHIND THE DEPARTING
FRONTAL SYSTEM...USHERING IN DRIER AIR OVER THE CWA FOR THE
BEGINNING OF NEXT WEEK. THE COMBINATION OF INVERSIONS AND WARMER AIR
ALOFT SHOULD KEEP MOST OF THE AREA CAPPED THROUGH MIDWEEK...ALLOWING
ONLY FOR SLIGHT CHANCE POPS MONDAY AND CHANCE POPS TUESDAY
AFTERNOON. THE AIRMASS BEGINS TO SATURATE AGAIN BY WEDNESDAY AS
ANOTHER TROUGH DIPS DOWN...AND THE MOIST AIR COMBINED WITH AN
APPROACHING SHORTWAVE WILL MAKE FOR GREATEST POPS WEDNESDAY
AFTERNOON/EVENING. IMPROVED DEEP LAYER MOISTURE AND GENERAL
TROUGHINESS OVER THE SOUTHEASTERN CONUS WILL KEEP THE PATTERN
UNSETTLED WITH MORE DIURNALLY DRIVEN CONVECTION THROUGH THE END OF
NEXT WEEK.
CLOUD COVER AT THE BEGINNING OF THE PERIOD WILL KEEP HIGH TEMPS
BELOW AVERAGE...AND HIGHS WILL REMAIN COOLER THAN NORMAL THROUGH THE
END OF NEXT WEEK DUE TO LOWER THICKNESS ADVECTION. LOWS WILL BE NEAR
AVERAGE FOR THE ENTIRE MEDIUM RANGE.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...A LINE OF CONVECTION EXTENDING FROM THE NORTHERN NC
FOOTHILLS TO I-26 CORRIDOR WAS RATHER SLOWLY MOVING EAST TOWARD THE
AIRFIELD OVERNIGHT HOURS. THIS LINE MAY AFFECT THE TERMINAL BETWEEN
7Z AND 9Z SAT AND TEMPO THUNDER WAS MENTIONED ACCORDINGLY. CURRENT
VFR CONDITIONS WILL DEGRADE TO MVFR ONCE THE LINE MOVES THE FIELD
AND MVFR CLOUD DECK WITH INTERMITTENT SHOWERS WILL CONTINUE THROUGH
THE MORNING HOURS. WITH DIURNAL HEATING AND THE PASSAGE OF UPPER
SHORT WAVE ENERGY ON SAT...SHOWERS AND THUNDERSTORMS WILL
RE-DEVELOPER DURING THE PRIME HEATING HOURS. LIGHT SOUTHERLY WINDS
WILL PREVAIL THRU THE PERIOD THOUGH STRONGER WIND GUSTS ARE POSSIBLE
IN THUNDERSTORMS.
ELSEWHERE...A LINE OF SHRA/TSTMS WAS MOVING EAST ACROSS THE NC
FOOTHILLS AND UPSTATE SC OVERNIGHT HOURS. AREAS BEHIND THIS LINE
WILL REMAIN RELATIVELY QUIET THOUGH INTERMITTENT SHOWERS WILL BE
SEEN INTO THE MORNING HOURS. ONCE AGAIN...KAVL MAY SEE PATCHY FOG
WITH BRIEF IFR VISBY/CEILING TOWARD THE SUNRISE. AN UPPER SHORT WAVE
ENERGY WILL SWING ACROSS THE REGION DURING THE DAY ON SAT. THIS WILL
COMBINE WITH DIURNAL INSTABILITY TO TRIGGER CONVECTION DURING THE
AFTERNOON HOURS. LIGHT SOUTHERLY WINDS WILL PREVAIL FOR MOST
LOCATIONS THOUGH STRONGER WIND GUSTS CAN NOT BE RULED OUT IN
THUNDERSTORMS. KAVL WILL SEE WINDS VEERING TO THE NORTH BY THE
EVENING HOURS.
OUTLOOK...CONVECTION WILL DEVELOP AGAIN SUNDAY...BUT COVERAGE SHOULD
BE DIMINISHING. BRIEF DRYING IS POSSIBLE ON MON AND TUE WITH HIGH
PRES FOLLOWING FROPA.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT MED 60% MED 76% HIGH 87% HIGH 93%
KGSP MED 71% MED 76% HIGH 82% MED 64%
KAVL HIGH 94% HIGH 83% HIGH 81% MED 60%
KHKY MED 63% HIGH 88% MED 68% MED 69%
KGMU MED 72% HIGH 80% HIGH 81% MED 64%
KAND MED 71% HIGH 83% HIGH 91% MED 61%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...JOH/MCAVOY
SHORT TERM...LG
LONG TERM...VISIN
AVIATION...JOH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
157 AM EDT SAT JUL 27 2013
.SYNOPSIS...
PRECIPITATION CHANCES WILL REMAIN IN THE FORECAST THROUGH THE
WEEKEND AS A SERIES OF UPPER LEVEL DISTURBANCES AND A COLD FRONT
PASS THROUGH. CONDITIONS LOOK TO IMPROVE SLIGHTLY FOR THE START OF
NEXT WEEK AS SURFACE HIGH PRESSURE BUILDS WHILE REDUCING CHANCES FOR
PRECIPITATION.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE INCREASING
OVER THE NC FOOTHILLS AND PORTIONS OF UPSTATE SC IN RESPONSE TO
INCREASING UPSLOPE FLOW AND PVA OVER THE REGION. POPS WERE INCREASED
ACCORDINGLY AND EXPECT THE COVERAGE OF PRECIP TO INCREASE THROUGH
THE OVERNIGHT HOURS. SO FAR...NONE OF STORMS HAVE REACHED SEVERE
LEVEL DUE TO LIMITED BUOYANCY. THE MAIN THREAT FROM THESE STORMS
WILL BE HEAVY RAINFALL AND LOCALIZED FLOODING.
AS OF 945 PM EDT FRIDAY...SHOWERS AND THUNDERSTORMS ARE GRADUALLY
INCREASING OVER NE GA...THE WRN UPSTATE AND THE CENTRAL AND SW NC
MTNS. THIS IS GENERALLY WHAT WAS EXPECTED...THOUGH IT/S A FEW HOURS
EARLIER THAN EXPECTED. I SUSPECT THAT THIS CONVECTION WILL CONTINUE
TO SLOWLY MOVE NORTHEAST THE REST OF THE NIGHT...AND IT/S POSSIBLE
THAT MORE WILL DEVELOP ALONG THE BLUE RIDGE AS THE LLVL FLOW
INCREASES LATE. THE STRENGTHENING WINDS WILL BE IN RESPONSE TO AN
APPROACHING SHORT WAVE WHICH SHOWS UP WELL ON THE RUC H5 ANALYSIS
AND THE WATER VAPOR IMAGERY PRETTY MUCH RIGHT OVER THE MISSISSIPPI
RIVER ATTM. LOCALLY HEAVY RAIN AND EVEN A SEVERE STORM ARE TWO STILL
LOOK LIKE A GOOD BET.
AS OF 600 PM EDT FRIDAY...UPPED POPS INTO THE LIKELY CATEGORY ACROSS
A BROAD SECTION OF THE CENTRAL PART OF THE FA LATER TONIGHT. MOST OF
THE CONVECTIVE ALLOWING MODELS DEVELOP SHOWERS AND THUNDERSTORMS
LATER TONIGHT AS THE LLVL FLOW INCREASES TO 20 TO 25 KTS AND A
RATHER POTENT SHORT WAVE APPROACHES FROM THE BEST. IT APPEARS THAT
RAIN CHANCES WILL BE HIGHEST ACROSS THE BLUE RIDGE AND OUT INTO THE
FOOTHILLS WHERE UPSLOPE WILL AID ASCENT. LOCALLY VERY HEAVY RAIN IS
POSSIBLE WITH THE STORMS...WHICH HAS BASICALLY BEEN THE STORY OF THE
SUMMER. WITH DRY MID-LEVEL AIR...A FEW AREAS OF LARGE HAIL DAMAGING
STRAIGHT LINE WINDS WILL ALSO BE POSSIBLE...ESPECIALLY EARLY ON IN
THE EVENT...SAY BETWEEN 8 PM AND MIDNIGHT.
PREVIOUS DISCUSSION...ISOLATED DEEP CONVECTION CONTINUES TO DEVELOP
ACROSS THE FOOTHILLS AND THE UPPER SAVANNAH RIVER VALLEY. A LACK OF
TRULY ROBUST INSTABILITY (DUE TO WARM MID-LEVEL TEMPS) IS LIMITING
THE VERTICAL DEVELOPMENT OF THE CONVECTION...AND THERE HAS BEEN NO
LIGHTNING ACTIVITY OBSERVED THUS FAR (IN FACT...CELLS HAVE NOT EVEN
COME CLOSE TO BEING ENOUGH TO PRODUCE LIGHTNING). NEVERTHELESS...CU
IS BEGINNING TO APPEAR SOMEWHAT AGITATED OVER THE HIGH TERRAIN...AND
AS THE ATM CONTINUES TO HEAT UP...COVERAGE AND INTENSITY OF
CONVECTION SHOULD GRADUALLY INCREASE. WE WILL CONTINUE TO ADVERTISE
A GRADUAL INCREASE IN POPS TO LOW/SOLID CHANCE ACROSS THE WESTERN
HALF OF THE AREA BY LATE AFTERNOON...WHILE HOLDING ON TO SLIGHT
COVERAGE AT BEST IN THE WEAKER INSTABILITY ACROSS OUR EASTERN
PIEDMONT ZONES.
THE SHORT TERM MODELS CONTINUE TO PICK UP ON A WEAK VORT MAX...
POSSIBLY CONVECTIVELY INDUCED AND A PRECURSOR TO THE PRIMARY SHORT
WAVE CURRENTLY APPROACHING THE MISS VALLEY...MOVING ACROSS THE CWA
THIS EVENING INTO THE EARLY PART OF THE OVERNIGHT. IN RESPONSE...
MOST MODELS...INCLUDING THE HIRES MODELS...HINT AT INCREASING
COVERAGE OF CONVECTION TONIGHT. OUR CURRENT EXPECTATION IS THAT THIS
WAVE WILL SWEEP THE MORE ROBUST CONVECTIVE ACTIVITY CURRENTLY
DEVELOPING OVER CENTRAL GEORGIA ACROSS THE WESTERN HALF OF THE CWA
THIS EVENING...SO WILL GENERALLY FEATURE 40-50 POPS ACROSS MUCH OF
THE AREA DURING THIS TIME. SHEAR IS WEAK AND INSTABILITY COULD
CERTAINLY BE BETTER...BUT AN ISOLATED PULSE SEVERE STORM WILL BE
POSSIBLE ALONG WITH THE THREAT OF HEAVY RAIN THREAT.
TOMORROW MAY BE AN INTERESTING DAY AS THE PRIMARY VORT MAX
APPROACHES FROM THE TENN VALLEY. DEEP LAYER FLOW WILL STRENGTHEN IN
ADVANCE OF THIS FEATURE SUCH THAT SHEAR IS QUITE RESPECTABLE FOR
MID-SUMMER (20-25 KTS 0-3 KM...30-35 KTS 0-6 KM). THE PRIMARY
CONCERN WILL BE WITH THE DEGREE OF INSTABILITY...AS THE
STRENGTHENING S/SE FLOW SHOULD ALSO RESULT IN PLENTY OF MORNING
STRATOCU. NEVERTHELESS...MODEL SOUNDINGS DEPICT QUITE A BIT OF
LINGERING DRY MID-LEVEL AIR...SO WE COULD SEE ENOUGH HEATING TO
REALIZE CLOSE TO 2000 J/KG CAPE VALUES. IF SO...WE MAY WELL SEE AN
ORGANIZED SEVERE WEATHER THREAT. CONSIDERING THE UNCERTAINTY ABOUT
THE DEGREE OF HEATING...THE CURRENT SPC /SEE TEXT/5 PERCENT AREA
APPEARS REASONABLE FOR DAY 2.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRI...NUMEROUS SHOWERS/THUNDERSTORMS SHOULD BE ON
GOING SAT EVENING OVER EASTERN SECTIONS...IN RESPONSE TO A VIGOROUS
VORT MAX MOVING THROUGH THE CAROLINAS. I EXPECT THAT THE MAIN BODY
OF SHOWERS/STORMS WILL MOVE EAST OF THE AREA BY MIDNIGHT.
HOWEVER...A WEAK COLD FRONT WILL SLIP SE TO THE LEE OF THE MOUNTAINS
BY DAYBREAK SUNDAY...SO WILL NEED TO HOLD ONTO SOME CHANCE POPS
OVERNIGHT FOR SOME UPSLOPE MOUNTAIN SHOWERS...AND PERHAPS SOME
SHOWERS AND THUNDERSTORMS INDUCED BY THE FRONT.
ON SUNDAY...THE FRONT WILL LINGER OVER THE REGION AS AN UPPER LOW
DIGS OVER THE GREAT LAKES. LOW LEVEL CONVERGENCE COMBINED WITH UPPER
DIFFLUENCE AND AFTERNOON CAPES PEAKING AROUND 1500J IN THE AFTERNOON
SHOULD BE ENOUGH FOR SCT TO NUMEROUS SHOWERS AND THUNDERSTORMS...
MOST NUMEROUS OVER EASTERN SECTIONS. SOME SHOWERS/STORMS COULD LINGER INTO
SUNDAY EVENING OVER THE EAST. HOWEVER...THE FRONT WILL FINALLY MOVE
EAST OF THE AREA OVERNIGHT WITH HIGH PRESSURE BUILDING IN FROM THE
WEST.
ON MONDAY...THE SURFACE HIGH IS FORECAST TO DOMINATE THE REGIONAL
WEATHER. THEREFORE...EXPECT A DRY DAY WITH MOSTLY CLEAR TO PARTLY
CLOUDY CONDITIONS. STAYED CLOSE TO CONSENSUS GUIDANCE FOR MOST GRID
FIELDS. MAX TEMPS WILL BE A COUPLE CATEGORIES BELOW AVERAGE ON
SUNDAY...WARMING TO ABOUT A CATEGORY BELOW AVERAGE MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...THE EXTENDED PERIOD BEGINS LATE MONDAY WITH
HIGH PRESSURE BUILDING IN OVER THE EAST COAST BEHIND THE DEPARTING
FRONTAL SYSTEM...USHERING IN DRIER AIR OVER THE CWA FOR THE
BEGINNING OF NEXT WEEK. THE COMBINATION OF INVERSIONS AND WARMER AIR
ALOFT SHOULD KEEP MOST OF THE AREA CAPPED THROUGH MIDWEEK...ALLOWING
ONLY FOR SLIGHT CHANCE POPS MONDAY AND CHANCE POPS TUESDAY
AFTERNOON. THE AIRMASS BEGINS TO SATURATE AGAIN BY WEDNESDAY AS
ANOTHER TROUGH DIPS DOWN...AND THE MOIST AIR COMBINED WITH AN
APPROACHING SHORTWAVE WILL MAKE FOR GREATEST POPS WEDNESDAY
AFTERNOON/EVENING. IMPROVED DEEP LAYER MOISTURE AND GENERAL
TROUGHINESS OVER THE SOUTHEASTERN CONUS WILL KEEP THE PATTERN
UNSETTLED WITH MORE DIURNALLY DRIVEN CONVECTION THROUGH THE END OF
NEXT WEEK.
CLOUD COVER AT THE BEGINNING OF THE PERIOD WILL KEEP HIGH TEMPS
BELOW AVERAGE...AND HIGHS WILL REMAIN COOLER THAN NORMAL THROUGH THE
END OF NEXT WEEK DUE TO LOWER THICKNESS ADVECTION. LOWS WILL BE NEAR
AVERAGE FOR THE ENTIRE MEDIUM RANGE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...CU HAVE DRIED UP WITH THE LOSS OF HEATING AND THE AIRFIELD
SHOULD EXPERIENCE SEVERAL HOURS OF FAIR WEATHER. LATER TONIGHT
CONDITIONS WILL BE FAVORABLE FOR NOCTURNAL CONVECTION AND I HAVE A
TEMPO GROUP FOR TSTMS FROM 06-09 UTC. STILL EXPECT STRENGTHENING
SOUTHERLY FLOW ACTING UPON AN INCREASINGLY MOIST LOW LEVEL AIR MASS
TO RESULT IN THE DEVELOPMENT OF WIDESPREAD STRATUS ACROSS THE AREA
LATE TONIGHT. CIGS MAY BE LOWER TONIGHT WITH SOME PCPN IN THE AREA
AND I TAKE THEM DOWN TO BKN010 AT 0900 UTC. ONLY SLOW IMPROVEMENT IS
EXPECTED THROUGH THE MORNING HOURS WITH THE MOIST SE FLOW AND
POSSIBLE ONGOING SHOWER OR TSTM ACTIVITY. MORE ACTIVITY IS LIKELY IN
THE AFTERNOON AS A STRONGER UPPER LOW MOVES THROUGH. EXPECTING S TO
SE WINDS THROUGH THE PERIOD.
ELSEWHERE...A BROKEN LINE OF SHRA/TSTMS IS SLOWLY ADVANCING ACROSS
THE GA. CONDITIONS BECOME FAVORABLE FOR CONVECTION LATER
TONIGHT...THOUGH I/M NOT SURE IF THIS LINE WILL MAKE IT OR IF WE
WILL HAVE TO WAIT FOR MORE STORMS. AS A COMPROMISE...I HAVE TEMPO
THUNDER PROBS FROM 03-07. STRATUS IS A GOOD BET TONIGHT WITH MOIST
SOUTHEAST FLOW AND A LLVL WIND FIELD INCREASING TO AROUND 20 KTS.
WENT RIGHT ON THE CUSP OF IFR/MVFR. A LOT WILL DEPEND ON HOW MUCH
RAIN FALLS...BUT AS A RULE THAT MUCH LLVL WIND SHOULD KEEP US FROM
SEEING REALLY LOW CIGS. I DID GO LOWER AT KAVL. MORE SHRA/TSTMS ARE
EXPECTED TMRW. WINDS WILL BE S TO SE THROUGH THE PERIOD.
OUTLOOK...CONVECTION WILL DEVELOP AGAIN SUNDAY...BUT COVERAGE SHOULD
BE DIMINISHING. BRIEF DRYING IS POSSIBLE ON MON AND TUE WITH HIGH
PRES FOLLOWING FROPA.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT MED 60% MED 76% HIGH 87% HIGH 93%
KGSP MED 71% MED 76% HIGH 82% MED 64%
KAVL HIGH 94% HIGH 83% HIGH 81% MED 60%
KHKY MED 63% HIGH 88% MED 68% MED 69%
KGMU MED 72% HIGH 80% HIGH 81% MED 64%
KAND MED 71% HIGH 83% HIGH 91% MED 61%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...JOH/MCAVOY
SHORT TERM...LG
LONG TERM...VISIN
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
342 AM CDT SAT JUL 27 2013
.DISCUSSION...
SHOWERS HAVE BEEN MOVING INTO THE WEST HALF OF MIDDLE TN EARLY
THIS MORNING AS A WEAK H5 TROF MOVES INTO THE REGION. TROF SHOULD
MOVE EAST OF THE REGION WITHIN THE NEXT FEW HOURS AND HRRR SHOWS
THESE SHOWERS ENDING LATER THIS MORNING.
VERY UNUSUAL FORECAST FOR MID SUMMER. H5 CLOSED LOW WILL MOVE
SLOWLY EAST THRU THE GREAT LAKES THIS WEEKEND. ASSOCIATED SFC LOW
WILL HELP BRING A COLD FRONT INTO NW MIDDLE TN LATE TODAY...AND TO
THE REST OF THE AREA BY MIDNIGHT. SCATTERED SHOWERS AND MAYBE A
FEW STORMS WILL REDEVELOP THIS AFTERNOON AND EARLY EVENING AHEAD
OF THE FRONT. RAINFALL AMOUNTS WILL BE LIGHT WITH LESS THAN 1/4
INCH IN MOST AREAS.
COOLER AND DRY WEATHER ON TAP FOR SUN/MON AS SFC RIDGE SETTLES
INTO MID TN. MONDAY MORNING MIN TEMPS COULD APPROACH RECORDS.
GFS GUIDANCE IS AN OUTLIER BY FORECASTING 2 DEGREES COLDER THAN
THE RECORD AT BNA...AND A WHOPPING 5 DEGREES COLDER THAN THE
RECORD AT CSV. SO...LEANED MORE TOWARD THE WARMER AND SEEMINGLY
MORE REASONABLE NAM/ECMWF GUIDANCE.
H5 HEIGHTS REBOUND BY TUESDAY AS GREAT LAKES LOW MOVES FURTHER
AWAY AND RIDGE REBUILDS ACROSS THE SOUTHERN U.S. HOWEVER...GFS AND
ECMWF SHOW WEAK NW FLOW ALOFT WITH A TROF APPROACHING THE MID
STATE TUE/WED...FOLLOWED BY ANOTHER BUT WEAKER COLD FRONT LATE
WEDNESDAY. WITH MEAN RH AND LIFT INCREASING...WILL GO WITH CHANCE
TYPE POPS TUESDAY THRU WEDNESDAY EVENING. GFS AND ECMWF BOTH SHOW
SIGNIFICANT QPF BULLS EYES BUT MAINLY IN SOUTHERN KY.
AFTER THE TROF MOVES AWAY...SOME DRYING IS EXPECTED THURSDAY AND
FRIDAY WITH TEMPS UP A FEW DEGREES AS THICKNESS/HEIGHTS EDGE
UPWARD. RAIN CHANCES MAY INCREASE AGAIN NEXT WEEKEND AS BOTH
MODELS SHOW YET ANOTHER WEAK FRONT MOVING SLOWLY INTO MIDDLE TN
FROM THE NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 85 61 81 60 / 40 10 0 0
CLARKSVILLE 83 56 80 58 / 30 10 0 0
CROSSVILLE 80 58 76 57 / 50 20 05 05
COLUMBIA 85 61 83 61 / 40 10 0 0
LAWRENCEBURG 84 61 83 62 / 40 10 0 0
WAVERLY 84 58 81 60 / 30 10 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
49
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 AM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT SAT JUL 27 2013
THE MAIN QUESTIONS FOR TODAY/TONIGHT ARE WITH HOW COLD IT WILL BE
ALONG WITH HOW FAR SOUTHWEST WILL THE RAIN SHOWERS MAKE IT.
CURRENTLY...A CLOSED MID LEVEL LOW CONTINUES TO SLOWLY DRIFT
ACROSS LAKE SUPERIOR WITH THREE MAIN SHORTWAVE TROUGHS ROTATING
AROUND IT LIKE SPOKES ON A WHEEL. THE SOUTHWESTERN SHORTWAVE HAS
HELPED TO PULL THE COLD CORE OF THE LOW SOUTHWARD ACROSS WESTERN
WISCONSIN. THIS HAS ALSO BROUGHT A LOW TO MID LEVEL BROKEN CLOUD
DECK AND SPORADIC VERY LIGHT RAIN SHOWERS DOWN WITH IT.
FOR TODAY...TEMPERATURES WILL GREATLY RELY UPON HOW MUCH CLOUD
COVER DEVELOPS. BASED ON 27.00Z NAM/GFS AND 27.06Z HRRR/RAP RH
FIELDS...EXPECT THAT THE MORE BROKEN TO OVERCAST CLOUD COVER WILL
BE ACROSS WESTERN WISCONSIN UNDER THE CORE OF THE LOW WITH IT
BECOMING MORE SCATTERED THE FURTHER SOUTHWEST YOU GO TOWARD IOWA.
AS A BASE FOR TEMPERATURES TODAY...MIXED DOWN FROM AROUND 850MB
DURING THE PEAK DIURNAL HEATING THIS AFTERNOON AND THEN ADJUSTED
DOWN A BIT BASED ON HOW OVERCAST CLOUD COVER IS. DOING THIS
YIELDS HIGHS IN THE UPPER 50S TO LOW 60S IN WESTERN TO NORTH
CENTRAL WISCONSIN AND LOW TO MID 60S INTO NORTHEAST IOWA. BASED ON
THESE HIGHS...SOME RECORD LOW MAXIMUM TEMPERATURES ARE IN DANGER
OF BEING BROKEN TODAY...SEE THE CLIMATE SECTION BELOW FOR LOCAL
RECORDS. GIVEN THE STEEP LOW LEVEL LAPSE RATES...RAIN SHOWERS ARE
EXPECTED BUT WILL BE ISOLATED TO SCATTERED AT TIMES TODAY.
EXPECT THAT SOME SHOWERS WILL PERSIST INTO TONIGHT...PARTICULARLY
IN NORTH CENTRAL WISCONSIN WHERE CLOUD COVER WILL ALSO BE MORE
PREVALENT. COULD BE PUSHING SOME RECORD LOWS...BUT THAT MAINLY
DEPENDS ON WHETHER SKIES CAN CLEAR OUT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 331 AM CDT SAT JUL 27 2013
THE LOW WILL START TO DRIFT EAST ACROSS THE GREAT LAKES ON SUNDAY
WITH GRADUALLY WARMING CONDITIONS EACH DAY INTO WEDNESDAY. SOME
SHOWERS COULD HANG ON ACROSS WESTERN WISCONSIN ON SUNDAY...BUT A
RIDGE OF HIGH PRESSURE WILL PUSH IN FROM THE WEST INTO MONDAY AND
BRING AN END TO THEM.
TUESDAY THEN APPEARS TO BE THE NEXT CHANCE FOR A MORE WIDESPREAD
RAINFALL...THOUGH CONFIDENCE IS NOT VERY HIGH IN THIS OCCURRING.
THE STRONGEST FORCING APPEARS TO SPLIT THE REGION AS ONE MID LEVEL
SHORT WAVE TROUGH TRACKS ACROSS SOUTHERN CANADA AND ANOTHER GOES
THROUGH MISSOURI. THE 27.00Z GEM IS THE MOST WIDESPREAD WITH ITS
QPF AS THE COLD FRONT/TROUGH COMES THROUGH WITH THE REST OF THE
27.00Z GUIDANCE REALLY BACKING OFF. SO...HAVE KEPT THE CHANCES IN
ON TUESDAY FOR NOW. THE BETTER CHANCE COULD COME ON WEDNESDAY AS
THE MAIN COLD FRONT DROPS THROUGH DURING PEAK HEATING.
AFTER A RIDGE OF HIGH PRESSURE MOVES IN ON THURSDAY...THE NEXT
SHOT FOR PRECIPITATION COMES IN ON FRIDAY ALONG A BAND OF WARM AIR
ADVECTION AHEAD OF THE NEXT SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1137 PM CDT FRI JUL 26 2013
LARGE AREA OF CLOUDS IN THE CYCLONIC FLOW REMAINS OVER MUCH
WISCONSIN AND EASTERN MINNESOTA. CEILINGS FOR THE MOST PART ARE
VFR OVER MINNESOTA BUT BECOME MVFR IN WISCONSIN. KLSE ALREADY HAS
HAD A SHORT PERIOD OF MVFR AND OBSERVATIONS AT 04Z INDICATE A
PRETTY SOLID MVFR DECK NORTH OF I94. THE 27.03Z RAP SUGGESTS THESE
LOWER CEILINGS WILL CONTINUE TO PROGRESS SOUTHWARD AND HAVE TAKEN
KLSE DOWN TO MVFR BASED ON THIS. WITH SOME HEATING AND MIXING
SATURDAY MORNING...THE CEILINGS SHOULD GO BACK UP TO VFR AND STAY
THERE FOR THE REMAINDER OF THE PERIOD. WILL LIKELY ALSO SEE SOME
GUSTS TO AROUND 20 KNOTS AGAIN DURING THE LATE MORNING AND
AFTERNOON. THE 27.00Z NAM CONTINUES TO SUGGESTS THAT ANY SHOWERS
THAT DEVELOP IN THE CYCLONIC FLOW WILL REMAIN NORTHEAST OF BOTH
TAF SITES AND WILL CONTINUE WITH A DRY FORECAST.
&&
.CLIMATE...WEEKEND
ISSUED AT 331 AM CDT SAT JUL 27 2013
THROUGH THE WEEKEND...THERE WILL BE POSSIBILITY FOR RECORD COLD
MAXIMUMS AND COLD MINIMUMS. HERE ARE SOME OF THE RECORDS FOR
THIS MORNINGS LOWS AND TODAYS HIGHS.
RECORD LOW TEMPERATURES FOR THIS MORNING...
AUSTIN MN 47 IN 1980
ROCHESTER MN 47 IN 1920
CHARLES CITY IA 47 IN 1971
DECORAH IA 46 IN 1962
MEDFORD WI 42 IN 1893
LA CROSSE WI 48 IN 1891
PRAIRIE DU CHIEN 45 IN 1911
SPARTA WI 42 IN 1971
RECORD LOW MAXIMUM TEMPERATURES FOR TODAY...
AUSTIN MN 67 IN 2005
ROCHESTER MN 64 IN 1981
CHARLES CITY IA 65 IN 1905
DECORAH IA 65 IN 1972
MEDFORD WI 62 IN 1945
LA CROSSE WI 69 IN 1981
PRAIRIE DU CHIEN 67 IN 1972
SPARTA WI 71 IN 2005
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...04
CLIMATE...BOYNE/HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CDT FRI JUL 26 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 349 PM CDT FRI JUL 26 2013
AT 3 PM...A SURFACE LOW WAS LOCATED OVER NORTHEAST WISCONSIN. A
COLD FRONT EXTENDED SOUTHWEST FROM THIS LOW THROUGH THE WISCONSIN
DELLS AND THE EASTERN PORTIONS OF GRANT COUNTY. SCATTERED SHOWERS
AND THUNDERSTORMS WERE FOUND AHEAD OF THIS FRONT. A SECONDARY COLD
FRONT FROM MEDFORD WISCONSIN TO WOOD LAKE MINNESOTA. ALONG AND
BEHIND THIS FRONT...THERE WERE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS.
FOR TONIGHT...THE 26.12Z MODELS ARE IN GOOD AGREEMENT THAT THE
900 TO 700 MB LAYER WILL REMAIN FAIRLY SATURATED ACROSS WISCONSIN
OVERNIGHT. AS A RESULT KEPT SKIES MAINLY BROKEN. MEANWHILE IN
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...IT IS LESS CLEAR SO WENT
WITH A SCATTERED TO BROKEN DECK OF CLOUDS IN THESE AREAS. WITH THE
MODELS SHOWING THAT THE ML CAPES QUICKLY DISSIPATING THIS
EVENING...JUST WENT WITH EVENING SHOWERS ALONG AND NORTH OF
INTERSTATE 94.
ON SATURDAY...THE MODELS SHOW THAT 850 MB TEMPERATURES WILL ONLY
RANGE FROM 3 TO 6C ACROSS WESTERN WISCONSIN AND 6 TO 8C IN
NORTHEAST IOWA AND SOUTHEAST MINNESOTA. THESE TEMPERATURES ARE 2
TO 3 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR...SO
EXPECTING RECORD OR NEAR RECORD MAXIMUM TEMPERATURES RANGING FROM
THE UPPER 50S TO MID 60S. NORMAL HIGH TEMPERATURES ARE IN THE
LOWER AND MID 80S. WITH 950 MB TO 800 MB LAPSE RATES OF 8 TO
10C/KM AND ML CAPES UP TO 100 J/KG...EXPECT ISOLATED TO SCATTERED
SHOWERS TO DEVELOP BY MID MORNING AND THEN CONTINUE INTO THE
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 349 PM CDT FRI JUL 26 2013
ON SATURDAY NIGHT...THE MODELS SHOW THAT A STRONG VORTICITY
MAXIMUM WILL MOVE SOUTHEAST ACROSS WISCONSIN. WITH GOOD 950 TO
650 MB...EXPECT THAT THE ISOLATED TO SCATTERED SHOWERS WILL
CONTINUE ACROSS WESTERN WISCONSIN. THE HIGHEST PRECIPITATION
CHANCES WILL EB FOUND NORTH OF THE INTERSTATE 94 CORRIDOR. THIS
VORT MAX WILL BE ACCOMPANIED WITH 2C 850 MB TEMPERATURES. THIS IS
2.5 TO 3 STANDARD DEVIATIONS BELOW NORMAL. FORTUNATELY IT LOOKS
LIKE THERE BE MAINLY MOSTLY CLOUDY SKIES ACROSS THE AREA OR WE
COULD BE POTENTIALLY LOOKING AT LOW TEMPERATURES FALLING TO AROUND
40 DEGREES. DUE TO THE CLOUDS...THESE TEMPERATURES WILL LIKELY
RANGE FROM THE MID 40S TO LOWER 50S.
ON SUNDAY...THE CLOSED 500 MB LOW OVER LAKE SUPERIOR WILL KEEP
UNUSUALLY 850 MB TEMPERATURES ACROSS THE REGION. 850 MB
TEMPERATURE ANOMALIES WILL RANGE FROM 2 TO 2.5 STANDARD DEVIATIONS
BELOW NORMAL. SINCE THE MOS TEMPERATURES TAKE IN CLIMATOLOGY...
STAYED AWAY FROM ANY BLEND THAT CONTAINED THEM AND WENT MORE WITH
A BLEND OF THE ACTUAL MODEL TEMPERATURES TO CAPTURE BETTER THE
UNUSUALLY COOL TEMPERATURES ACROSS THE REGION. LIKE SATURDAY...
THE 950 TO 800 MB LAPSE RATES WILL RANGE FROM 8 TO 10 C/KM AND ML
CAPES WILL CLIMB UP TO 100 J/KG ACROSS WESTERN WISCONSIN. DUE TO
THIS KEPT A MENTION OF ISOLATED TO SCATTERED SHOWERS.
ON MONDAY AND MONDAY NIGHT...THE MODELS ARE SHOWING 500 MB RIDGING
WILL DEVELOP IN THE WAKE OF THE CLOSED 500 MB LOW ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THIS WILL KEEP THE FRONTOGENESIS AND
BEST 850 MB MOISTURE TRANSPORT WELL TO OUR SOUTHWEST. WITH THE
EXCEPTION OF THE GEM...THE REMAINDER OF THE MODELS HAVE THE AREA
DRY FOR THIS TIME PERIOD. THIS MAKES A LOT SENSE WHEN CONSIDERING
THE DRY DEW POINTS ACROSS THE REGION...THUS...TOOK THE
PRECIPITATION CHANCES OUT OF THE FORECAST. IN ADDITION WITH THE
850 MB TEMPERATURES RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL...STAYED AWAY FROM ANY BLEND WHICH CONTAINED THE MOS TO
BETTER REPRESENT THE COOLNESS RESIDING ACROSS THE REGION.
ON WEDNESDAY NIGHT...BOTH THE GFS AND ECMWF ARE IN AGREEMENT THAT
THERE WILL BE STRONG SUBSIDENCE ACROSS THE REGION IN THE WAKE OF
COLD FRONT FRONT. DUE TO THIS...REMOVED THE LOW PRECIPITATION
CHANCES THAT WERE IN THE ALL BLEND DATA BASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1137 PM CDT FRI JUL 26 2013
LARGE AREA OF CLOUDS IN THE CYCLONIC FLOW REMAINS OVER MUCH
WISCONSIN AND EASTERN MINNESOTA. CEILINGS FOR THE MOST PART ARE
VFR OVER MINNESOTA BUT BECOME MVFR IN WISCONSIN. KLSE ALREADY HAS
HAD A SHORT PERIOD OF MVFR AND OBSERVATIONS AT 04Z INDICATE A
PRETTY SOLID MVFR DECK NORTH OF I94. THE 27.03Z RAP SUGGESTS THESE
LOWER CEILINGS WILL CONTINUE TO PROGRESS SOUTHWARD AND HAVE TAKEN
KLSE DOWN TO MVFR BASED ON THIS. WITH SOME HEATING AND MIXING
SATURDAY MORNING...THE CEILINGS SHOULD GO BACK UP TO VFR AND STAY
THERE FOR THE REMAINDER OF THE PERIOD. WILL LIKELY ALSO SEE SOME
GUSTS TO AROUND 20 KNOTS AGAIN DURING THE LATE MORNING AND
AFTERNOON. THE 27.00Z NAM CONTINUES TO SUGGESTS THAT ANY SHOWERS
THAT DEVELOP IN THE CYCLONIC FLOW WILL REMAIN NORTHEAST OF BOTH
TAF SITES AND WILL CONTINUE WITH A DRY FORECAST.
&&
.CLIMATE...WEEKEND
ISSUED AT 349 PM CDT FRI JUL 26 2013
THROUGH THE WEEKEND...THERE WILL BE POSSIBILITY FOR RECORD COLD
MAXIMUMS AND COLD MINIMUMS. HERE ARE SOME OF THE RECORDS FOR
TONIGHT AND SATURDAY.
RECORD LOW TEMPERATURES FOR TONIGHT...
AUSTIN MN 47 IN 1980
ROCHESTER MN 47 IN 1920
CHARLES CITY IA 47 IN 1971
DECORAH IA 46 IN 1962
MEDFORD WI 42 IN 1893
LA CROSSE WI 48 IN 1891
PRAIRIE DU CHIEN 45 IN 1911
SPARTA WI 42 IN 1971
RECORD LOW MAXIMUM TEMPERATURES FOR SATURDAY...
AUSTIN MN 67 IN 2005
ROCHESTER MN 64 IN 1981
CHARLES CITY IA 65 IN 1905
DECORAH IA 65 IN 1972
MEDFORD WI 62 IN 1945
LA CROSSE WI 69 IN 1981
PRAIRIE DU CHIEN 67 IN 1972
SPARTA WI 71 IN 2005
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
CLIMATE...BOYNE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1025 AM EDT SAT JUL 27 2013
.UPDATE...
WEAK FRONTAL BOUNDARY SITUATED ACROSS THE MID MISSISSIPPI RIVER
VALLEY THIS MORNING. 500MB ANALYSIS SHOWS A SHEAR AXIS ACROSS
WESTERN GA. A BROKEN LINE OF SHOWERS HAS FORMED ALONG AND JUST
AHEAD OF THIS FEATURE. THE LATEST RUNS OF THE HRRR SEEM TO HANDLE
THIS WELL...SO HAVE RE-ORIENTED POPS ACCORDINGLY.
IN ADDITION...DUE TO THE THICK CLOUD COVER AND PRECIP...HAVE DECREASED
MAX TEMPS ACROSS THE NORTHERN PART OF THE STATE A FEW DEGREES.
&&
.PREV DISCUSSION... /ISSUED 748 AM EDT SAT JUL 27 2013/
PREV DISCUSSION... /ISSUED 434 AM EDT SAT JUL 27 2013/
SHORT TERM /TODAY THROUGH SUNDAY/...
PRIMARY CONCERN IS LIKELIHOOD OF CONVECTION THIS AFTERNOON AND
EVENING. APPROACHING SHORT WAVE TROUGH JUST WEST OF CWA THIS
MORNING YET MEAN RH AND VERTICAL MOTION LACKING. IR/WV IMAGERY
ALSO CONFIRMING THIS BAND OF DRIER AIR CURRENTLY ACROSS WESTERN GA
UP THROUGH ERN TN. DEEPER MOISTURE JUST WEST OF TROUGH AXIS IN
MS/AL. THIS MOISTURE WILL PUSH INTO CWA THIS AFTERNOON AND EVENING
SO EXPECT DEVELOPMENT OF SCT TSRA AROUND 18-20Z WITH 30-50PCT
COVERAGE...GREATEST OVER ERN AND WC/SW GA. A FEW STORMS COULD
APPROACH SVR CRITERIA BUT MLCAPE AND THETA-E LAPSE RATES DO NOT
WARRANT ANYTHING MORE INTENSE THAN THAT. OVER NORTH AND MUCH OF
MIDDLE GA...GFS HAS VERY LITTLE CAPE DUE TO SLIGHTLY DRIER LOW
LEVELS AND THICKER MID CLOUDS. AFTER SOME PATCHY FOG AGAIN SUNDAY
MORNING...SHOULD BE EVEN LESS COVERAGE OF STORMS OVER NORTH AND
WEST GA SUNDAY PM AS SHORT WAVE PASSES AND DRIER AIR PUSHES
FURTHER IN. HAVE KEPT POPS IN CHC CATEGORY OVER SOUTH AND EAST
COUNTIES BUT MUCH OF NORTH GA WILL BE POP-FREE.
WENT ABOVE MAX TEMP GUIDANCE FOR SAT AND SUN BASED ON LESS CLOUDS/
PRECIP THAN PREV THOUGHT. USED BLEND OF 30 DAY BIAS CORRECTED TEMPS
WITH GREATER WEIGHT TOWARD THE MAV FOR MIN TEMPS.
SNELSON
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
WITH SFC RIDGING BUILDING INTO THE CWA NEAR THE BEGINNING OF THE
LONG TERM AND NO STRONG WAVES PEGGED IN THE UPPER LEVELS...THIS MAY
PROVIDE A SHORT BREAK IN THE HIGHER THAN CLIMO POPS. WITH SFC RIDGE
CENTERED OVER THE OHIO VALLEY ON MONDAY...THE GFS KEEPS THE CWA DRY
WHEREAS THE ECMWF LINGERS SOME BETTER MOISTURE ACROSS CENTRAL
GEORGIA. FORECAST IS NEAR A BLEND OF THE TWO...WITH ONLY A SLIGHT
CHANCE MENTIONED ACROSS CENTRAL GEORGIA FOR THE AFTERNOON. WITH A
SERIES OF SHORTWAVES MOVING THROUGH MID-WEEK...WILL SEE A RETURN
OF THE ABOVE NORMAL POPS. GFS HAS BEEN FAIRLY CONSISTENT WITH
TIMING BETWEEN LAST NIGHT AND TONIGHT WHEREAS THE ECMWF HAS HAD
SOME RUN TO RUN DIFFERENCES. 00Z ECMWF HAS COME INTO BETTER
AGREEMENT AGAIN WITH THE 00Z GFS AS OPPOSED TO THE 12Z ECMWF. MAIN
IMPACT WITH THESE SHORTWAVES WILL BE AN INCREASE IN POPS FOR THE
WEDNESDAY TO THURSDAY TIME FRAME WITH THE BEST CHANCES ACROSS
NORTH GEORGIA ON WEDNESDAY. GIVEN SOME CONSISTENCY IN TIMING WITH
THE GFS...HAVE GONE AHEAD AND INTRODUCED LIKELY POPS FOR FAR NORTH
GEORGIA ON WEDNESDAY. PLENTY OF INSTABILITY WITH THE SYSTEM...BUT
SHEAR IS LACKING. STILL WITH INSTABILITY ALONE...ITS ENOUGH THAT
SOME OF THE STORMS COULD BECOME STRONG. GFS AND ECMWF ARE
CONSISTENT WITH HIGHER RAINFALL AMOUNTS ACROSS NORTH GEORGIA WITH
BOTH MODELS DEPICTING JUST UNDER 2 INCHES IN THE WEDNESDAY/THURSDAY
TIME FRAME. BY FRIDAY...UPPER DISTURBANCE IS EAST OF THE AREA AND
THAT WILL BRING US BACK INTO A MORE TYPICAL SUMMERTIME
PATTERN...AT LEAST IN TERMS OF CONVECTION.
11
AVIATION...
12Z UPDATE...
IFR VSBYS AND CIGS SHOULD BE CLEARING BY 13-14Z. OTHERWISE...PRIMARY
CONCERN IS CHC FOR TSRA THIS AFTERNOON/EVENING. SEEING SOME SIGNS
THAT COVERAGE WILL NOT BE AS WIDESPREAD ACROSS MOST OF THE AREA AS
THOUGHT EARLIER. HAVE INCREASED POP TO TEMPO FROM 20Z-00Z FOR
MOST SITES BUT LATER FORECASTS MAY NEED TO DECREASE DURATION OF
TEMPO OR REMOVE IT ALL TOGETHER. SE SFC WINDS WILL SHIFT TO SW
13-15Z WITH SPEEDS INCREASING TO 6-8KTS. ALREADY SEEING SSW WINDS
AT ATL. IN SPITE OF DRIER AIR MOVING INTO NORTH GA EARLY SUNDAY
MORNING...WILL LIKELY SEE SOME STRATUS AGAIN.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TSRA LIKELIHOOD/COVERAGE THIS AFTERNOON.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 88 65 / 50 40 20 10
ATLANTA 85 69 86 66 / 40 30 20 10
BLAIRSVILLE 81 63 82 57 / 50 30 10 10
CARTERSVILLE 85 66 86 60 / 40 30 10 10
COLUMBUS 89 72 89 70 / 40 40 20 20
GAINESVILLE 84 68 85 64 / 50 30 20 10
MACON 90 69 90 69 / 40 40 30 20
ROME 86 66 86 59 / 40 30 10 10
PEACHTREE CITY 85 67 86 62 / 30 30 20 10
VIDALIA 90 72 89 72 / 40 40 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LISTEMAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1033 AM CDT SAT JUL 27 2013
.DISCUSSION...
ISSUED 1033 AM CDT SAT JUL 27 2013
UNSEASONABLY COOL AIRMASS HAS SETTLED INTO CENTRAL ILLINOIS THIS
MORNING...WITH 15Z/10AM TEMPS RANGING FROM THE LOWER 60S NORTH OF
PEORIA TO THE LOWER 70S ALONG/SOUTH OF I-70. SKIES STARTED OUT
CLEAR...BUT HAVE BECOME PARTLY SUNNY AS SCT-BKN DIURNAL CU HAVE
DEVELOPED ACROSS THE AREA. VERY COLD TEMPS ALOFT ASSOCIATED WITH
DEEP UPPER LOW SPINNING OVER THE WESTERN GREAT LAKES WILL SUPPORT
STEEP MID-LEVEL LAPSE RATES AND PLENTY OF CLOUD DEVELOPMENT. MAY
EVEN SEE SOME SPRINKLES FROM TIME TO TIME...AS FORECAST SOUNDINGS
SHOW A 3000 TO 4000-FOOT THICK CLOUD LAYER ENHANCED BY A SHORT-WAVE
TROUGH ROTATING ACROSS NORTH-CENTRAL ILLINOIS. HRRR SUGGESTS
SCATTERED SPRINKLES AHEAD OF THIS FEATURE AS WELL...AND HAVE SEEN
SOME WEAK RETURNS UPSTREAM ON KDVN RADAR OVER THE PAST HOUR.
HAVE THEREFORE UPDATED THE FORECAST TO INCREASE CLOUD COVER AND
ADD SCATTERED SPRINKLES DURING THE LATE MORNING INTO THE
AFTERNOON. ALSO NUDGED HIGHS UP A DEGREE OR TWO...AS JULY SUN HAS
WARMED READINGS A BIT FASTER THIS MORNING THAN PREVIOUSLY THOUGHT.
ZONE UPDATE HAS ALREADY BEEN ISSUED.
BARNES
&&
.AVIATION...
ISSUED 608 AM CDT SAT JUL 27 2013
VFR CONDITIONS SHOULD PREVAIL AT ALL TAF SITES NEXT 24HRS. SKIES
WILL START AS CLEAR AT ALL SITES...BUT BELIEVE CU/SC WILL DEVELOP
THIS MORNING AND BE SCATTERED FOR MOST OF THE DAY. THERE COULD BE
A 3-4 HOURS WHERE THE CU/SC BECOMES BROKEN AT TIMES SO HAVE TEMPO
GROUP FOR ALL SITES FOR THE LATE MORNING TO EARLY AFTERNOON. CLOUD
COVER SHOULD BE DIURNAL SO HAVE SKIES CLEARING OUT AGAIN AROUND
SUNSET. WINDS WILL BE NORTHWEST MOST OF THE DAY BUT THEN BECOME
VARIABLE AND LIGHTER AROUND SUNSET.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 303 AM CDT SAT JUL 27 2013
SHORT TERM...TODAY THROUGH MONDAY
COLD FRONT AT 07Z HAD CLEARED ALL BUT OUR SOUTHEAST FEW COUNTIES
WHILE SKIES CLEARED FOR MUCH OF THE CWA. LIGHT W/NW WINDS WERE
SLOWLY BRINGING IN COOLER AND DRIER AIR WITH MID 50S DEW POINTS
NOTED WEST OF THE IL RIVER. UNSEASONABLY COLD AIRMASS POISED TO
OUR NORTHWEST...WITH A FALL-LIKE +2C 850MB 00Z TEMPERATURE AT
INTERNATIONAL FALLS. THIS MODIFIED CANADIAN AIRMASS WILL SHIFT
SOUTHEAST ACROSS THE REGION THIS WEEKEND ON THE BACK SIDE OF A
STRONG CLOSED 500MB LOW DRIFTING ACROSS THE GREAT LAKES. STEEP LOW
LEVEL LAPSE RATES AND CYCLONIC FLOW SHOULD ALLOW PLENTY OF DIURNAL
CU FORMATION TODAY AND SUNDAY. WITH DEEPER MOISTURE STAYING
FARTHER NORTHEAST FEEL ANY SPRINKLES WILL BE TOO ISOLATED TO
MENTION IN FORECAST. MAIN STORY THROUGH SUNDAY WILL BE UNUSUALLY
COOL TEMPERATURES FOR LATE JULY. 850MB READINGS ARE FORECAST TO DIP AS
LOW AS +5-7C OVER THE NORTHERN CWA LATER TODAY AND TONIGHT. THUS
RECORD COOL HIGHS TODAY /GENERALLY LOWER 70S/ AND RECORD LOWS
TONIGHT /NEAR 50F/ WILL BE IN JEOPARDY. SEE CLIMATE SECTION BELOW
FOR SPECIFIC NUMBERS FOR OFFICIAL CLIMATE SITES.
TEMPERATURES WILL BEGIN TO MODERATE LATER SUNDAY AND ESPECIALLY
MONDAY AS HIGH PRESSURE SHIFTS SOUTH OF THE OHIO VALLEY AND THE
NEXT LOW DEVELOPS OVER THE CENTRAL PLAINS. A WARM FRONT LIFTING
NORTHEAST ACROSS MISSOURI COULD SPREAD SCATTERED THUNDERSTORMS AS
FAR EAST AS WESTERN IL LATE MONDAY AFTERNOON WITH BETTER CHANCES
MONDAY NIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
00Z MODELS HAVE COME INTO A BIT BETTER AGREEMENT IN HANDLING THE CENTRAL
PLAINS LOW WHICH IS FORECAST TO TRACK EAST TOWARDS THE CENTRAL
MISSISSIPPI RIVER/LOWER OHIO RIVER VALLEY REGION BY LATE TUESDAY.
NAM IS FARTHEST NORTH/QUICKEST WHILE ECMWF HAS TRENDED FARTHER
NORTH AND NOW LOOKS SIMILAR TO CURRENT AND PREVIOUS GFS SOLUTIONS.
THUS WILL EXPAND LIKELY POPS NORTH FOR MUCH OF THE SOUTHERN HALF
OF THE CWA MONDAY NIGHT AND TUESDAY WITH CHANCE POPS FARTHER NORTH.
MOISTURE RETURN SOUTH OF THE SYSTEM AND FORCING SUGGEST A MODERATE
1-2 INCH QPF EVENT WHERE EVENTUAL PRECIP PATH DOES LAY OUT.
WED-FRI APPEARS GENERALLY DRY WITH LOW AMPLITUDE NW FLOW ALOFT AND
TEMPERATURES RETURNING TO NEAR NORMAL. A WEAK UPPER WAVE IS
PROGGED TO MOVE THROUGH IN THE WED/WED NIGHT TIME FRAME BUT WITH
LIMITED FORCING THIS FAR SOUTH ONLY HAVE SLIGHT CHANCE POPS. A
MORE RESPECTABLE SYSTEM MAY PUSH EAST INTO THE MIDWEST TOWARDS THE
END OF THE WEEK. QUITE A LARGE MODEL SPREAD IN TIMING AND LOCATION
SO CURRENT LOW CHANCE POPS ON FRIDAY LOOK GOOD.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
615 AM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT JUL 27 2013
AN ABNORMALLY COOL AND DRY AIRMASS IS CURRENTLY IN PLACE OVER THE
CENTRAL AND NORTHERN PLAINS IN THE FORM OF A SURFACE RIDGE WHICH
EXTENDS FROM SOUTHERN KANSAS NORTHWARD THROUGH NEBRASKA AND INTO THE
NORTHERN PLAINS. THIS AIRMASS IS CHARACTERIZED BY TEMPS IN THE UPPER
40S TO MID 50S ACROSS EASTERN NEBRASKA AND IN THE UPPER 50S TO LOWER
60S THROUGHOUT EASTERN KANSAS. EXPECT THESE TEMPS TO CONTINUE TO
DROP THROUGH THE REST OF THE OVERNIGHT HOURS AND SETTLE AROUND THE
MID TO UPPER 50S FOR OUR FORECAST AREA. RADAR TRENDS SHOW A VERY
WEAK COMPLEX OF SHOWERS AND THUNDERSTORMS IN CENTRAL NEBRASKA. THIS
COMPLEX LOOKS TO BE ASSOCIATED WITH SOME MODERATE ISENTROPIC LIFT
ALONG THE 310K THETA E SURFACE. SOMEWHAT SURPRISING IS THE AMOUNT OF
LIGHTNING DETECTED WITH THESE STORMS AS RAP SOUNDINGS ONLY INDICATE
AROUND 100-200 J/KG OF ELEVATED INSTABILITY FOR THESE STORMS TO WORK
WITH. NONETHELESS HAVE GONE WITH A CHANCE OF ISOLATED THUNDERSTORMS
FOR THE NORTH CENTRAL AND CENTRAL PART OF THE STATE...INCLUDING THE
FAR WESTERN ZONES OF THE FORECAST AREA THROUGH THE MORNING
HOURS...BEFORE GRADUALLY DISSIPATING DURING THE AFTERNOON. WITH THE
COOLER/DRIER AIRMASS IN PLACE OVER THE FORECAST AREA EXPECT TEMPS TO
BE WELL BELOW SEASONAL NORMS...WITH HIGHS REACHING THE MID TO UPPER
70S...WITH PERHAPS A FEW AREAS REACHING 80 DEGREES. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING AS ANOTHER ROUND OF WARM AIR ADVECTION SHOWERS
COMMENCE ACROSS WESTERN AND CENTRAL KANSAS. EXPECT THESE SHOWERS TO
SPILL INTO OUR AREA AND SPREAD EASTWARD OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING. ANOTHER COOL NIGHT IS IN STORE FOR THE AREA ON
SATURDAY NIGHT...AS LOWS WILL LIKELY DROP INTO THE LOWER TO MID 50S
ACROSS THE EASTERN HALF OF THE CWA...WHILE AREAS IN THE WESTERN HALF
WILL STAY IN THE MID TO UPPER 50S.
.LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 324 AM CDT SAT JUL
27 2013
MOISTURE AND PRECIP SLOWLY INCREASE FROM WEST TO EAST ACROSS
EASTERN KANSAS ON SUNDAY...BECOMING LIKELY SUNDAY NIGHT INTO
MONDAY. HIGHS SUNDAY WITH INCREASING CLOUD COVER AND RAIN CHANCES
EXPECTED TO BE IN THE MIDDLE 70S FOR MUCH OF THE AREA. BY 12Z
MONDAY...SURFACE LOW OVER THE TX PANHANDLE GETS A BOOST FROM A
PASSING SHORTWAVE TROF ROLLING OFF THE HIGH PLAINS...INCREASING
MOISTURE ADVECTION AND THE LLJ AND FOCUSING PRECIPITATION ACROSS
EASTERN KANSAS. STILL SOME DISCREPANCIES AS TO HOW FAR NORTH THE
BRUNT OF THE RAIN WILL FALL...WITH NAM ALONG THE I70 CORRIDOR AND
EC FARTHER SOUTHWARD TOWARD SE KS. WILL FAVOR POPS OVER THE
SOUTHERN HALF OF THE AREA AND NOTE THAT PRECIP AMOUNTS COULD BE A
FEW INCHES OR MORE IN SOME LOCATIONS. NO WATCH AT THIS TIME BUT
WILL NEED TO MONITOR EVOLUTION FOR POSSIBLE LOCALIZED FLOODING
CONCERNS ON MONDAY.
SYSTEM MOVES EAST BY MONDAY NIGHT AND EXPECT PRECIP TO END QUICKLY
W TO E EARLY TUESDAY. MAINLY DRY CONDITIONS FORECAST THROUGH
THURSDAY. ZONAL FLOW SLOWLY TRANSITIONS TO WNW FLOW AROUND THE
SOUTHERN UPPER HIGH...AND THIS SLOWLY WARMS TEMPERATURES INTO THE
LOWER 80S TUESDAY TO THE UPPER 80S BY THURSDAY. MAY SEE THE NEXT
CHANCE FOR RAINFALL ON FRIDAY AS ANOTHER SW TROF TRAVERSES THROUGH
THE FLOW BUT HAVE NOT GONE TOO HIGH ON CHANCES THIS FAR OUT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 611 AM CDT SAT JUL 27 2013
A BATCH OF WEAK SHOWERS AND THUNDERSTORMS WILL APPROACH KMHK
WITHIN THE NEXT HOUR AND WILL LIKELY REMAIN NEAR THE TERMINAL
THROUGH 15Z. THE OUTER EXTENT OF THE SHOWERS WILL APPROACH KTOP
AND KMHK BRINGING THE POSSIBILITY OF SOME LIGHT SHOWERS THROUGH 14
TO 15Z. BY NOON THESE SHOWERS SHOULD DISSIPATE LEAVING CLOUDY
SKIES WHICH WILL GRADUALLY CLEAR THROUGH THE REMAINDER OF THE
FORECAST PERIOD.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEIGHTON
LONG TERM...67
AVIATION...LEIGHTON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
505 AM CDT SAT JUL 27 2013
...CORRECTED...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT JUL 27 2013
AN ABNORMALLY COOL AND DRY AIRMASS IS CURRENTLY IN PLACE OVER THE
CENTRAL AND NORTHERN PLAINS IN THE FORM OF A SURFACE RIDGE WHICH
EXTENDS FROM SOUTHERN KANSAS NORTHWARD THROUGH NEBRASKA AND INTO THE
NORTHERN PLAINS. THIS AIRMASS IS CHARACTERIZED BY TEMPS IN THE UPPER
40S TO MID 50S ACROSS EASTERN NEBRASKA AND IN THE UPPER 50S TO LOWER
60S THROUGHOUT EASTERN KANSAS. EXPECT THESE TEMPS TO CONTINUE TO
DROP THROUGH THE REST OF THE OVERNIGHT HOURS AND SETTLE AROUND THE
MID TO UPPER 50S FOR OUR FORECAST AREA. RADAR TRENDS SHOW A VERY
WEAK COMPLEX OF SHOWERS AND THUNDERSTORMS IN CENTRAL NEBRASKA. THIS
COMPLEX LOOKS TO BE ASSOCIATED WITH SOME MODERATE ISENTROPIC LIFT
ALONG THE 310K THETA E SURFACE. SOMEWHAT SURPRISING IS THE AMOUNT OF
LIGHTNING DETECTED WITH THESE STORMS AS RAP SOUNDINGS ONLY INDICATE
AROUND 100-200 J/KG OF ELEVATED INSTABILITY FOR THESE STORMS TO WORK
WITH. NONETHELESS HAVE GONE WITH A CHANCE OF ISOLATED THUNDERSTORMS
FOR THE NORTH CENTRAL AND CENTRAL PART OF THE STATE...INCLUDING THE
FAR WESTERN ZONES OF THE FORECAST AREA THROUGH THE MORNING
HOURS...BEFORE GRADUALLY DISSIPATING DURING THE AFTERNOON. WITH THE
COOLER/DRIER AIRMASS IN PLACE OVER THE FORECAST AREA EXPECT TEMPS TO
BE WELL BELOW SEASONAL NORMS...WITH HIGHS REACHING THE MID TO UPPER
70S...WITH PERHAPS A FEW AREAS REACHING 80 DEGREES. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING AS ANOTHER ROUND OF WARM AIR ADVECTION SHOWERS
COMMENCE ACROSS WESTERN AND CENTRAL KANSAS. EXPECT THESE SHOWERS TO
SPILL INTO OUR AREA AND SPREAD EASTWARD OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING. ANOTHER COOL NIGHT IS IN STORE FOR THE AREA ON
SATURDAY NIGHT...AS LOWS WILL LIKELY DROP INTO THE LOWER TO MID 50S
ACROSS THE EASTERN HALF OF THE CWA...WHILE AREAS IN THE WESTERN HALF
WILL STAY IN THE MID TO UPPER 50S.
.LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 324 AM CDT SAT JUL
27 2013
MOISTURE AND PRECIP SLOWLY INCREASE FROM WEST TO EAST ACROSS
EASTERN KANSAS ON SUNDAY...BECOMING LIKELY SUNDAY NIGHT INTO
MONDAY. HIGHS SUNDAY WITH INCREASING CLOUD COVER AND RAIN CHANCES
EXPECTED TO BE IN THE MIDDLE 70S FOR MUCH OF THE AREA. BY 12Z
MONDAY...SURFACE LOW OVER THE TX PANHANDLE GETS A BOOST FROM A
PASSING SHORTWAVE TROF ROLLING OFF THE HIGH PLAINS...INCREASING
MOISTURE ADVECTION AND THE LLJ AND FOCUSING PRECIPITATION ACROSS
EASTERN KANSAS. STILL SOME DISCREPANCIES AS TO HOW FAR NORTH THE
BRUNT OF THE RAIN WILL FALL...WITH NAM ALONG THE I70 CORRIDOR AND
EC FARTHER SOUTHWARD TOWARD SE KS. WILL FAVOR POPS OVER THE
SOUTHERN HALF OF THE AREA AND NOTE THAT PRECIP AMOUNTS COULD BE A
FEW INCHES OR MORE IN SOME LOCATIONS. NO WATCH AT THIS TIME BUT
WILL NEED TO MONITOR EVOLUTION FOR POSSIBLE LOCALIZED FLOODING
CONCERNS ON MONDAY.
SYSTEM MOVES EAST BY MONDAY NIGHT AND EXPECT PRECIP TO END QUICKLY
W TO E EARLY TUESDAY. MAINLY DRY CONDITIONS FORECAST THROUGH
THURSDAY. ZONAL FLOW SLOWLY TRANSITIONS TO WNW FLOW AROUND THE
SOUTHERN UPPER HIGH...AND THIS SLOWLY WARMS TEMPERATURES INTO THE
LOWER 80S TUESDAY TO THE UPPER 80S BY THURSDAY. MAY SEE THE NEXT
CHANCE FOR RAINFALL ON FRIDAY AS ANOTHER SW TROF TRAVERSES THROUGH
THE FLOW BUT HAVE NOT GONE TOO HIGH ON CHANCES THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1111 PM CDT FRI JUL 26 2013
VFR PREVAILS AT KTOP/KFOE/KMHK WITH FOCUS BEING ON OVERNIGHT FOG
POTENTIAL AND POSSIBLE SHOWERS SATURDAY. MID LEVEL CLOUDS OBSERVED
OVER SOUTH CENTRAL NEBRASKA WILL SHIFT SOUTHEAST TOWARDS SITES
OVERNIGHT. THIS FACTOR COMBINED WITH DRIER AIR AT THE LOW LEVELS
AND WINDS THRU 2KFT STAYING MIXY SHOULD KEEP DENSE FOG POTENTIAL
LOW. WIDELY SCATTERED SHOWERS PUSHING SOUTHEAST OVERNIGHT MAY
STILL REACH KMHK AFT 14Z. OTHERWISE NORTH WINDS SHOULD RESIDE
NEAR 10 KTS BEFORE WEAKENING TO AROUND 5 KTS AFT 11Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEIGHTON
LONG TERM...67
AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
634 AM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
TODAY...PER UNR UA SOUNDING AND THE RAP AND NAM MODELS...IT LOOKS
LIKE THERE IS A MOIST AND MODESTLY UNSTABLE EML OPERATING ACROSS THE
FCST AREA. THE NAM...RAP...HRRR AND GEMREG MODELS SEEM TO HAVE A
HANDLE ON THIS DISTURBANCE WITH DIFFERENCES IN THE LOCATION OF THE
RAINFALL. THE CONSENSUS IS FOR THE STORMS ACROSS WRN AND SWRN NEB TO
DECAY OR MOVE OUT OF THE FCST AREA EARLY THIS MORNING WHILE THE
SECOND BAND ACROSS NCNTL NEB CONTINUES TO OPERATE THROUGHOUT THE
MORNING AND THEN DECAYS DURING THE AFTERNOON.
SPC PUBLISHED THIS DISCUSSION AT 742Z...MODERATE MIDLEVEL WAA AND
FRONTOGENESIS IS LOCATED OVER WRN/CNTRL NEB THIS MORNING. IN
ADDITION...A PLUME OF MOISTURE AT 600-700 MB AND STEEP MIDLEVEL
LAPSE RATES IS YIELDING MODERATE MUCAPE VALUES UPWARDS OF 1000 J/KG.
THIS BUOYANCY COMBINED WITH THE ZONE OF FOCUSED MESOSCALE ASCENT IS
RESULTING IN SCATTERED THUNDERSTORM DEVELOPMENT OVER THE AREA. IN
ADDITION...A 60 KT MIDLEVEL NNWLY JET IS CONTRIBUTING TO STRONG
EFFECTIVE BULK SHEAR ON THE ORDER OF 40-60 KT...WHICH IS SUPPORTIVE
OF ELEVATED SUPERCELL DEVELOPMENT. THIS ENVIRONMENT MAY RESULT IN
ISOLATED INSTANCES OF LARGE HAIL DURING THE MORNING...BUT THE THREAT
IS TOO MARGINAL FOR A WW.
TONIGHT...SOME MODEL SOLNS...THE NAM IN PARTICULAR...SUGGEST ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SWRN
NEB. THE GEMREG IS FARTHER SOUTH HOLDS THE QPF ACROSS KS.
THIS WEATHER SHOULD BE GENERATED BY A DISTURBANCE...CURRENTLY ACROSS
WRN MT...WHICH WILL DROP SOUTH THROUGH THE NW FLOW AND MAINLY AFFECT
THE CNTL HIGH PLAINS BUT THE NAM SHOWS A BURST OF CONVECTION FIRING
ACROSS SWRN NEB. GIVEN THE NORTHWEST FLOW UNDERWAY AND THE APPARENT
FERTILE ENVIRONMENT FOR RAINFALL...THE NAM IS A CREDIBLE SOLN. SO
TSTMS ARE POSSIBLE TONIGHT...MAINLY SOUTH OF INTERSTATE 80.
HIGH TEMPS TODAY SHOULD REMAIN IN THE 70S WITH THE COOL SPOT ACROSS
CUSTER COUNTY...NEAR 70 FOR A HIGH THERE. LOWS TONIGHT IN THE 40S
AND 50S LOOK REASONABLE GIVEN THE COOL HIGH ACROSS SRN MANITOBA AND
BACKED SFC WINDS TUGGING ON THE COOL AIR FROM THE NORTH.
.LONG TERM...
.SUNDAY THROUGH MONDAY...
A FAIRLY COOL PERIOD STARTS THE WEEK AS MODELS ARE IN GOOD AGREEMENT
FOR A SLOW TRANSITION TO A FAIRLY ACTIVE AND WET START OF THE
WEEK. SEVERAL BOUNDARIES WILL COME INTO PLAY AS MOISTURE POOLS
ACROSS THE WEST IN A PREVAILING UPSLOPE PATTERN. A FRONTAL
BOUNDARY WILL EXTEND SOUTH ON THE HIGH PLAINS...WHILE SURFACE
RIDGING REACHES FROM THE NORTHERN MIDWEST THROUGH THE OHIO VALLEY.
AT THIS TIME MONDAY EVENING APPEARS A GOOD SHOT FOR SEVERE
THUNDERSTORM DEVELOPMENT AS THE UPPER RIDGE AXIS WEAKENS AND
EMBEDDED WAVES MOVE EAST IN THE EVENING. IF ALL PANS OUT GOOD
INSTABILITY EXTENDS THROUGH THE FAR NORTHWEST SANDHILLS THAT WOULD
PROVIDE THE ENVIRONMENT FOR SEVERE STORMS MONDAY NIGHT. CONSIDERABLE
CLOUD COVERAGE WILL HELP KEEP TEMPERATURES DOWN AS WELL WITH HIGHS
MAINLY IN 70S... COMPARED TO NORMALS THAT WOULD BE CLOSER TO THE
UPPER 80S.
.TUESDAY THROUGH SATURDAY...
THE PATTERN REMAINS OVERALL PROGRESSIVE WITH SURFACE BOUNDARIES IN
PLACE FOR A CONTINUED CHANCE FOR DAILY THUNDERSTORM ACTIVITY. AS THE
FLOW BECOMES MORE ZONAL TEMPERATURES WILL TREND TOWARD NORMAL BY MIDWEEK.
THE EMBEDDED WAVES CREATE CHALLENGES AS TO THE AREAL COVERAGE OF
STORMS. THE UPPER RIDGE STRENGTHENS ACROSS THE INTERMOUNTAIN
REGION THROUGH MIDWEEK THEN WEAKENS AS THE NEXT UPPER LOW MOVES
INTO THE NORTHEAST PACIFIC. THE RISING HEIGHTS MIDWEEK WILL HELP
SHIFT THE BETTER CHANCE FOR RAIN NORTH UNTIL THE APPROACH OF THE
WEEKEND. TEMPERATURES REBOUND IN THE FAR WEST TUESDAY...ALTHOUGH
IF MODELS SLOW DOWN TEMPERATURES MAY STRUGGLE TO REACH THE 80S.
FOR NOW TRENDED TEMPERATURES UP BEYOND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT JUL 27 2013
VFR IS EXPECTED MOST AREAS TODAY AND TONIGHT. ISOLATED
THUNDERSTORMS WOULD APPEAR TO BE EXITING THE FCST AREA RATHER
QUICKLY THIS MORNING. SATELLITE INDICATES SOME ENHANCEMENT/INSTABILITY
SUGGESTING PERHAPS REDEVELOPMENT IS POSSIBLE. OTHERWISE THIS
DISTURBANCE SHOULD EXIT SOUTH THIS MORNING.
A NEW DISTURBANCE...CURRENTLY ACROSS SERN MT/NERN WY...IS NOT
HANDLED BY ANY MODEL AND IT WOULD APPEAR ON TRACK TO SPREAD
ISOLATED TO SCATTERED SHOWERS AND TSTMS ACROSS WRN NEB THIS AM.
MEANWHILE...THE MODELS ARE ONBOARD WITH A THIRD DISTURBANCE
PRODUCING SHOWERS AND TSTMS LATE THIS AFTERNOON/EVENING ACROSS ERN WY/ERN
COLO/WRN KS WHICH SHOULD REMAIN SOUTH AND WEST OF THE FCST AREA.
THE NAM SUGGESTS SOME OF THIS ACTIVITY COULD DEVELOP ACROSS SWRN
NEB LATE TONIGHT...FROM 06Z ONWARD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...KECK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1047 AM EDT SAT JUL 27 2013
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT OFFSHORE TODAY. A LOW OVER
THE GREAT LAKES WILL MOVE TO THE EAST WITH AN ASSOCIATED COLD
FRONT THAT WILL APPROACH FROM THE WEST SATURDAY NIGHT AND SUNDAY.
HIGH PRESSURE WILL BUILD IN ON MONDAY. INCREASING CHANCES FOR
SHOWERS WILL DEVELOP THE MIDDLE OF NEXT WEEK AHEAD OF THE NEXT
COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...SHOWERS AND THUNDERSTORMS BEGINNING TO
FILL IN JUST TO OUR WEST OVER THE MIDLANDS OF SOUTH CAROLINA. THE
1200 UTC NAM IS A LITTLE MORE AGGRESSIVE IN DEVELOPING/MOVING
CONVECTION INTO THE AREA LATER THIS AFTERNOON. WE CURRENTLY HAVE
LOW CHANCE POPS FOR THESE AREAS AND WILL LEAVE FOR NOW ALTHOUGH WE
MAY NEED TO ADJUST UPWARD WITH THE NEXT UPDATE. TEMPERATURE AND
CLOUD COVER TRENDS ARE ON TRACK.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...ACTIVE FIRST HALF OF THE PERIOD AS AN UPPER
IMPULSE ROTATING AROUND ANOMALOUSLY DEEP UPPER TROUGH DRIVES A COLD
FRONT ACROSS THE CAROLINAS. THIS OCCURS IN AN ENVIRONMENT WITH
NEARLY 2 INCH PWATS AND MODERATELY STEEP ML LAPSE RATES...SO
CONVECTION SHOULD BE PRETTY WIDESPREAD...AND WILL BUMP TO LOW-LIKELY
SUNDAY AFTN/EVE. DO NOT ANTICIPATE ANY SEVERE...BUT WITH HIGH PWATS
IN PLACE HEAVY RAIN COULD OCCUR WITHIN ANY TSTM. ACTUAL SURFACE
FRONT WILL NOT MOVE OFFSHORE UNTIL LATE MONDAY...BUT MUCH DRIER AIR
BEGINS TO ADVECT INTO THE AREA AHEAD OF THE SURFACE BOUNDARY. SO
WHILE THERE MAY STILL BE ISOLATED CONVECTION...TYPICAL SUMMERTIME
ACTIVITY...ON MONDAY...IT WILL BE MUCH LESS ACTIVE THAN WHAT OCCURS
ON SUNDAY.
MAX TEMPS BOTH DAYS WILL BE A LITTLE BELOW NORMAL FOR THE END OF
JULY...MID/UPR 80S. LOWS AT NIGHT WILL FALL INTO THE 70-73
RANGE...TYPICAL FOR MID-SUMMER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM SATURDAY...BROAD UPPER RIDGING AND A RATHER
NON-DESCRIPT SURFACE PRESSURE PATTERN TO BEGIN THE EXTENDED QUICKLY
CHANGES WED-FRI AS UPPER TROUGH RELOADS ACROSS THE EASTERN CONUS.
TUESDAY MAY END UP THE WARMEST DAY OF THE PERIOD AS BROAD UPPER
RIDGING AND SURFACE HIGH PRESSURE MOVE ACROSS THE AREA. ALTHOUGH AN
ISOLATED DIURNAL TSTM CANNOT BE RULE OUT...WILL CARRY ONLY SCHC AS
ANY COVERAGE WILL BE ISOLATED. TEMPS TUESDAY WILL BE RIGHT AROUND
CLIMO FOR HIGHS AND LOWS.
COLD FRONT APPROACHES LATE TUESDAY BUT APPEARS TO GET HUNG UP OVER
THE AREA. THIS SETS UP A RATHER STRANGE SITUATION FOR MID-SUMMER AS
A BROAD LOW PRESSURE MOVES ACROSS THE SOUTHEAST AND OVER THE
CAROLINAS WED/THU ALONG THIS BOUNDARY. EVEN A WEAK BAROCLINIC LOW
THIS TIME OF YEAR IS ABNORMAL...BUT THIS SEASON HAS BEEN QUITE
ATYPICAL THUS FAR...SO WHY NOT! AT THE VERY LEAST...INCREASING
MOISTURE COMBINED WITH A POTENT VORT ALOFT WILL CAUSE BETTER RAIN
CHANCES WED/THU BEFORE DRYING BEGINS ON FRIDAY. COMBINATION OF
REDUCED MID-LEVEL THICKNESSES AND CLOUDS/RAIN WILL KEEP HIGH TEMPS
BELOW CLIMO WED/THU BEFORE RETURNING TO SEASONABLE LEVELS FRIDAY.
MINS THROUGH THE WEEK WILL AVERAGE A DEGREE OR TWO ABOVE NORMAL.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...HIGH CONFIDENCE FOG/STRATUS WILL BURN OFF AS ADVERTISED
IN TAFS. VFR EXPECTED THE REMAINDER OF THE MORNING ALTHOUGH CANNOT
RULE OUT A BRIEF MVFR CIG AS CUMULUS DEVELOPS. LOCAL HRRR SUGGESTS
NO CONVECTION AT THE COAST WITH SHOWERS AND THUNDERSTORMS DEVELOPING
NEAR KFLO 20-21Z AND A HOUR OR TWO LATER AT KLBT. THIS IS CONSISTENT
WITH OTHER MODELS. WILL INDICATE VCTS AT KFLO/KLBT DUE TO UNCERTAINTY
WITH TIMING.
THUNDERSTORMS WILL END DURING THE EVENING BUT LIGHT SHOWERS COULD
CONTINUE THROUGH THE OVERNIGHT HOURS. DESPITE BROKEN CLOUD COVER
THERE IS MODERATE CONFIDENCE MVFR/IFR CONDITIONS WILL DEVELOP
AGAIN AT KFLO/KLBT IN THE PRE-DAWN HOURS WITH TEMPO MVFR AT THE
COASTAL TERMINALS.
EXTENDED OUTLOOK...SCATTERED SHOWERS/THUNDERSTORMS SUNDAY AND
MONDAY AS ANOTHER COLD FRONT APPROACHES THE TERMINALS. OTHERWISE
VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...NO CHANGES TO THE COASTAL WATERS FORECAST
THIS MORNING AS LIGHT WINDS AND WEAK SEAS PREVAIL.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...LARGE AREA OF HIGH PRESSURE WELL
OFFSHORE...AND A WEAK COLD FRONT SLOWLY MOVING ACROSS THE CAROLINAS
DURING THE SHORT TERM...CREATE A WEAK GRADIENT AND LIGHT WINDS
THROUGH THE EARLY PART OF NEXT WEEK. AHEAD OF THIS FRONT...SW WINDS
WILL BE PREDOMINANT AT AROUND 10 KTS...VEERING TO THE THE WEST AT 10
KTS OR LESS ONLY VERY LATE MONDAY NIGHT. ALTHOUGH THESE WINDS WILL
BE LIGHT...THEY WILL PERSIST FOR A CONSIDERABLE TEMPORAL
PERIOD...THUS DRIVING SEAS TO 2-4 FT EACH DAY. NO SIGNIFICANT SWELL
WILL EXIST WITHIN THE SPECTRUM.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE OFFSHORE AND A
WEAKENING/RESIDUAL BOUNDARY NEAR THE AREA CREATES SOUTHERLY WINDS
WITH LITTLE DIRECTIONAL CHANGE...WITH SPEEDS AROUND 10
KTS...INCREASING TO NEAR 15 KTS LATE WEDNESDAY. SOUTHERLY RETURN
FLOW AROUND OFFSHORE HIGH PRODUCES A 2-3FT/8SEC SE SWELL...WHICH
COMBINES WITH LOW-AMPLITUDE WIND WAVES TO CREATE 2-4 FT SEAS THROUGH
THE PERIOD. LATE TUESDAY AND WEDNESDAY...WEAK BUT MUCH-LONGER PERIOD
SWELL AHEAD OF WEAKENING TROPICAL STORM DORIAN WILL ENTER THE LOCAL
WATERS. ATTM...MAXIMUM SWELL IS FORECAST TO BE 2-3FT/11-12 SEC ON
WEDNESDAY. THIS COULD CREATE SLIGHTLY HIGHER WAVES ACROSS THE WATERS
LATE IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...SHK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
752 AM EDT SAT JUL 27 2013
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT OFFSHORE TODAY. A LOW OVER
THE GREAT LAKES WILL MOVE TO THE EAST WITH AN ASSOCIATED COLD
FRONT THAT WILL APPROACH FROM THE WEST SATURDAY NIGHT AND SUNDAY.
HIGH PRESSURE WILL BUILD IN ON MONDAY. INCREASING CHANCES FOR
SHOWERS WILL DEVELOP THE MIDDLE OF NEXT WEEK AHEAD OF THE NEXT
COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...LOW STRATUS AND FOG HAVE DEVELOPED ALONG AND
WEST OF THE INTERSTATE 95 CORRIDOR. THE FLORENCE AIRPORT JUST
RECENTLY WENT DOWN TO 1/4 MILE VISIBILITY! WITH ONLY SOME CIRRUS
ALOFT THERE IS NOTHING TO KEEP THE SUN FROM BURNING THIS LOW DECK
OFF QUICKLY THIS MORNING. 06Z MODELS DROPPED THEIR TEMPERATURE
FORECASTS IN LINE WITH MY PREVIOUS THOUGHTS SO NO SIGNIFICANT
CHANGES ARE NECESSARY. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
IT SEEMS AS IF MOST OF THE DISCUSSIONS I HAVE WRITTEN OVER THE PAST
FEW WEEKS HAVE TALKED ABOUT HOW UNUSUAL THE WEATHER PATTERN IS FOR
JULY. TODAY IS NO EXCEPTION: AN ANOMALOUSLY STRONG AND COLD UPPER
LOW OVER LAKE SUPERIOR HAS A TROUGH EXTENDING SOUTHWARD INTO THE MID
SOUTH REGION. 500 MB HEIGHTS AND 850 MB TEMPS BOTH FALL TO -3 TO -4
STANDARD DEVIATIONS FROM NORMAL ACROSS THE UPPER MIDWEST. THE
MID-LEVEL MOISTURE CHANNEL AHEAD OF THIS TROUGH WILL MOVE INTO THE
EASTERN CAROLINAS THIS EVENING AND SHOULD REMAIN OVERNIGHT. AT THE
SURFACE A COLD FRONT ASSOCIATED WITH THE UPPER TROUGH LIES FROM
INDIANA TO MISSOURI. AN OLD STALLED FRONT IS DECAYING WELL EAST OF
THE CAROLINA COAST...BUT SATELLITE IMAGERY AND DATA FROM NOAA BUOY
41002 INDICATE A SMALL LOW HAS WRAPPED UP ABOUT 200 MILES EAST OF
CAPE FEAR. THIS LOW IS FORECAST TO MOVE NORTHEAST AND AWAY FROM THE
AREA WITH VIRTUALLY NO IMPACT LOCALLY.
SATELLITE IMAGERY ALSO SHOWS FAIRLY THICK CIRRUS OVER THE WESTERN
HALF OF THE CAROLINAS ASSOCIATED WITH PERSISTENT THUNDERSTORM
ACTIVITY OVERNIGHT. THERE MAY BE MORE OPAQUE CLOUD COVER HERE THAN
ACCOUNTED FOR IN 00Z MODELS...AND THAT LEADS INTO THE UNCERTAINTY
WITH TODAY`S FORECAST. ASSUMING WE HAVE MORE CLOUDS THAN SUN THIS
MORNING BUT WE GET A FAIR AMOUNT OF SUNSHINE FROM NOON ONWARD...
HIGHS SHOULD REACH THE UPPER 80S INLAND AND MID 80S AT THE COAST. IF
THICKER CIRRUS (OR EVEN MID-LEVEL CLOUDINESS) IS MORE PERSISTENT
THAN EXPECTED THEN HIGHS COULD RUN SEVERAL DEGREES LOWER. I HAVE
TRENDED THE FORECAST TOWARD THE LOWER END OF THE GFS/NAM MOS
ENVELOPE...BUT NOT NEARLY AS COOL AS THE MOST RECENT GFS LAMP MOS
BULLETINS WHICH ARE ONLY SHOWING 82-84 AREA-WIDE.
AS THE ATMOSPHERE MOISTENS AND THE SUBSIDENCE INVERSION BETWEEN
700-550 MB ERODES...SHOWER AND T-STORM CHANCES SHOULD INCREASE LATER
TODAY. THE BEST CHANCE OF AFTERNOON CONVECTION WILL EXIST ACROSS
THE SOUTH CAROLINA PEE DEE REGION PLUS ROBESON COUNTY NC WHERE I
HAVE 30-40 POPS FORECAST. THE COAST SHOULD REMAIN DRY WITH A COOLER
ONSHORE FLOW AND A LATER EROSION OF THE MID-LEVEL CAP. DESPITE
COOLER SURFACE TEMPERATURES TONIGHT I HAVE BROUGHT SHOWER AND
T-STORM CHANCES ALL THE WAY DOWN TO THE COAST AS A FAVORABLY
POSITIONED 200 MB JET ACROSS VIRGINIA ADDS SYNOPTIC LIFT TO AN
ALREADY CONDITIONALLY UNSTABLE AIRMASS. LOWS TONIGHT SHOULD FALL
INTO THE LOWER 70S MOST AREAS...PERHAPS A FEW DEGREES WARMER AT THE
BEACHES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...ACTIVE FIRST HALF OF THE PERIOD AS AN UPPER
IMPULSE ROTATING AROUND ANOMALOUSLY DEEP UPPER TROUGH DRIVES A COLD
FRONT ACROSS THE CAROLINAS. THIS OCCURS IN AN ENVIRONMENT WITH
NEARLY 2 INCH PWATS AND MODERATELY STEEP ML LAPSE RATES...SO
CONVECTION SHOULD BE PRETTY WIDESPREAD...AND WILL BUMP TO LOW-LIKELY
SUNDAY AFTN/EVE. DO NOT ANTICIPATE ANY SEVERE...BUT WITH HIGH PWATS
IN PLACE HEAVY RAIN COULD OCCUR WITHIN ANY TSTM. ACTUAL SURFACE
FRONT WILL NOT MOVE OFFSHORE UNTIL LATE MONDAY...BUT MUCH DRIER AIR
BEGINS TO ADVECT INTO THE AREA AHEAD OF THE SURFACE BOUNDARY. SO
WHILE THERE MAY STILL BE ISOLATED CONVECTION...TYPICAL SUMMERTIME
ACTIVITY...ON MONDAY...IT WILL BE MUCH LESS ACTIVE THAN WHAT OCCURS
ON SUNDAY.
MAX TEMPS BOTH DAYS WILL BE A LITTLE BELOW NORMAL FOR THE END OF
JULY...MID/UPR 80S. LOWS AT NIGHT WILL FALL INTO THE 70-73
RANGE...TYPICAL FOR MID-SUMMER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM SATURDAY...BROAD UPPER RIDGING AND A RATHER
NON-DESCRIPT SURFACE PRESSURE PATTERN TO BEGIN THE EXTENDED QUICKLY
CHANGES WED-FRI AS UPPER TROUGH RELOADS ACROSS THE EASTERN CONUS.
TUESDAY MAY END UP THE WARMEST DAY OF THE PERIOD AS BROAD UPPER
RIDGING AND SURFACE HIGH PRESSURE MOVE ACROSS THE AREA. ALTHOUGH AN
ISOLATED DIURNAL TSTM CANNOT BE RULE OUT...WILL CARRY ONLY SCHC AS
ANY COVERAGE WILL BE ISOLATED. TEMPS TUESDAY WILL BE RIGHT AROUND
CLIMO FOR HIGHS AND LOWS.
COLD FRONT APPROACHES LATE TUESDAY BUT APPEARS TO GET HUNG UP OVER
THE AREA. THIS SETS UP A RATHER STRANGE SITUATION FOR MID-SUMMER AS
A BROAD LOW PRESSURE MOVES ACROSS THE SOUTHEAST AND OVER THE
CAROLINAS WED/THU ALONG THIS BOUNDARY. EVEN A WEAK BAROCLINIC LOW
THIS TIME OF YEAR IS ABNORMAL...BUT THIS SEASON HAS BEEN QUITE
ATYPICAL THUS FAR...SO WHY NOT! AT THE VERY LEAST...INCREASING
MOISTURE COMBINED WITH A POTENT VORT ALOFT WILL CAUSE BETTER RAIN
CHANCES WED/THU BEFORE DRYING BEGINS ON FRIDAY. COMBINATION OF
REDUCED MID-LEVEL THICKNESSES AND CLOUDS/RAIN WILL KEEP HIGH TEMPS
BELOW CLIMO WED/THU BEFORE RETURNING TO SEASONABLE LEVELS FRIDAY.
MINS THROUGH THE WEEK WILL AVERAGE A DEGREE OR TWO ABOVE NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...HIGH CONFIDENCE FOG/STRATUS WILL BURN OFF AS ADVERTISED
IN TAFS. VFR EXPECTED THE REMAINDER OF THE MORNING ALTHOUGH CANNOT
RULE OUT A BRIEF MVFR CIG AS CUMULUS DEVELOPS. LOCAL HRRR SUGGESTS
NO CONVECTION AT THE COAST WITH SHOWERS AND THUNDERSTORMS DEVELOPING
NEAR KFLO 20-21Z AND A HOUR OR TWO LATER AT KLBT. THIS IS CONSISTENT
WITH OTHER MODELS. WILL INDICATE VCTS AT KFLO/KLBT DUE TO UNCERTAINTY
WITH TIMING.
THUNDERSTORMS WILL END DURING THE EVENING BUT LIGHT SHOWERS COULD
CONTINUE THROUGH THE OVERNIGHT HOURS. DESPITE BROKEN CLOUD COVER
THERE IS MODERATE CONFIDENCE MVFR/IFR CONDITIONS WILL DEVELOP
AGAIN AT KFLO/KLBT IN THE PRE-DAWN HOURS WITH TEMPO MVFR AT THE
COASTAL TERMINALS.
EXTENDED OUTLOOK...SCATTERED SHOWERS/THUNDERSTORMS SUNDAY AND
MONDAY AS ANOTHER COLD FRONT APPROACHES THE TERMINALS. OTHERWISE
VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...LIGHT EAST WINDS CONTINUE OUT AT THE
OFFSHORE BUOYS AND ALONG THE SOUTH CAROLINA COAST. ALONG THE NC
COAST WHERE ONSHORE WINDS WERE EVEN LIGHTER A LANDBREEZE HAS
DEVELOPED WITH OFFSHORE WIND DIRECTIONS NOTED. WINDS SHOULD AVERAGE
EASTERLY THIS MORNING...TURNING MORE SOUTHEASTERLY TO SOUTHERLY THIS
AFTERNOON WITH A DEVELOPING SEABREEZE. NO SIGNIFICANT CHANGES ARE
NECESSARY. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
BERMUDA HIGH PRESSURE IS CENTERED WELL OFFSHORE...ALMOST IN THE
CENTRAL ATLANTIC...BUT IS STILL DRAWING A SOUTHERLY STREAM OF AIR
NORTHWARD FROM THE CARIBBEAN THROUGH THE WESTERN ATLANTIC. AN OLD
STALLED FRONT IS DISSIPATING OFF THE CAROLINA COAST...BUT SATELLITE
IMAGERY AND NOAA BUOY 41002 BOTH INDICATE A COMPACT LOW HAS
DEVELOPED ABOUT 200 MILES EAST OF CAPE FEAR. THIS LOW IS FORECAST TO
MOVE NORTHEASTWARD TODAY...WITH VERY LITTLE DIRECT IMPACT ON OUR
WEATHER. OUR EASTERLY WINDS THIS MORNING ARE PROBABLY A RESULT OF
THE OFFSHORE LOW...BUT THIS EFFECT SHOULD WANE WITH THE FLOW TURNING
MORE SOUTHERLY WITH TIME. WIND SPEEDS WILL REMAIN 10 KNOTS OR LESS
THROUGH TONIGHT.
A COLD FRONT EXTENDING FROM INDIANA TO MISSOURI WILL MOVE INTO THE
APPALACHIANS BY DAYBREAK SUNDAY. INCREASING MOISTURE AHEAD OF THE
FRONT MAY YIELD ISOLATED SHOWERS AND T-STORMS TONIGHT...BUT WITH
BETTER CHANCES EXPECTED SUNDAY.
AREA BUOYS REPORT SEA HEIGHTS AROUND 2 FEET CURRENTLY. A 9 SECOND
SOUTHEAST SWELL WILL DEVELOP TONIGHT WHICH MAY ADD A FOOT TO SEA
HEIGHTS AWAY FROM SHORE.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...LARGE AREA OF HIGH PRESSURE WELL
OFFSHORE...AND A WEAK COLD FRONT SLOWLY MOVING ACROSS THE CAROLINAS
DURING THE SHORT TERM...CREATE A WEAK GRADIENT AND LIGHT WINDS
THROUGH THE EARLY PART OF NEXT WEEK. AHEAD OF THIS FRONT...SW WINDS
WILL BE PREDOMINANT AT AROUND 10 KTS...VEERING TO THE THE WEST AT 10
KTS OR LESS ONLY VERY LATE MONDAY NIGHT. ALTHOUGH THESE WINDS WILL
BE LIGHT...THEY WILL PERSIST FOR A CONSIDERABLE TEMPORAL
PERIOD...THUS DRIVING SEAS TO 2-4 FT EACH DAY. NO SIGNIFICANT SWELL
WILL EXIST WITHIN THE SPECTRUM.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE OFFSHORE AND A
WEAKENING/RESIDUAL BOUNDARY NEAR THE AREA CREATES SOUTHERLY WINDS
WITH LITTLE DIRECTIONAL CHANGE...WITH SPEEDS AROUND 10
KTS...INCREASING TO NEAR 15 KTS LATE WEDNESDAY. SOUTHERLY RETURN
FLOW AROUND OFFSHORE HIGH PRODUCES A 2-3FT/8SEC SE SWELL...WHICH
COMBINES WITH LOW-AMPLITUDE WIND WAVES TO CREATE 2-4 FT SEAS THROUGH
THE PERIOD. LATE TUESDAY AND WEDNESDAY...WEAK BUT MUCH-LONGER PERIOD
SWELL AHEAD OF WEAKENING TROPICAL STORM DORIAN WILL ENTER THE LOCAL
WATERS. ATTM...MAXIMUM SWELL IS FORECAST TO BE 2-3FT/11-12 SEC ON
WEDNESDAY. THIS COULD CREATE SLIGHTLY HIGHER WAVES ACROSS THE WATERS
LATE IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
649 AM EDT SAT JUL 27 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH EAST ACROSS THE REGION THROUGH
TONIGHT. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE OHIO VALLEY
ON SUNDAY WHILE AN UPPER LEVEL LOW SPINS ACROSS THE GREAT LAKES.
THE UPPER LEVEL LOW WILL MOVE SLOWLY NORTHEAST THROUGH MONDAY
WHILE THE SURFACE HIGH EXPANDS ACROSS AREA. TEMPERATURES WILL BE
BELOW NORMAL THROUGH THE BEGINNING OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN GREAT AGREEMENT THIS MORNING. HAVE USED THE RAP AND
HRRR FOR TIMING OF PCPN.
AS WAS ADVERTISED YESTERDAY...A PIECE OF ENERGY IS BEING DRAWN NE
ACRS THE OHIO VALLEY THIS MORNING WHILE AN UPR LVL CLOSED LOW SLOWLY
ROTATES SOUTHWARD ACRS THE WRN GREAT LAKES. THIS ENERGY WILL
COMBINE WITH SOME LOW TO MID LVL FORCING OUT AHEAD OF A COLD
FRONT TO BRING WIDESPREAD SHOWERS TO MUCH OF THE REGION DURING THE
MORNING HOURS. INSTABILITY IS WEAK ENOUGH THAT THUNDER IS NOT
ANTICIPATED. FOR THIS AFTERNOON...THE COLD FRONT WILL PUSH EAST
INTO THE WRN CWFA WHILE WIDESPREAD PCPN PUSHES TO THE EAST. THERE
COULD BE A GAP BETWEEN DEVELOPMENTAL PCPN ALONG/AHEAD OF THE FRONT
VERSUS DEPARTING WIDESPREAD PCPN. WE SHOULD SEE ENOUGH DAYTIME
HEATING TO ALLOW FOR A LITTLE MORE INSTABILITY THIS AFTN FOR A
MENTION OF THUNDER. GIVEN PWATS OF 1.75 INCHES...SOME OF THE
SHOWERS MAY BE MODERATE TO LOCALLY HEAVY.
CLOUDS AND PCPN WILL HOLD TEMPERATURES DOWN. HIGHS IN THE LOWER TO
MID 70S STILL LOOK REASONABLE WHICH ARE ABOUT 10 DEGREES BELOW
NORMAL FOR LATE JULY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
S/WV ENERGY ROTATING SE INTO THE REGION AROUND UPR LVL CLOSED LOW
WILL PUSH THE COLD FRONT EAST OF THE AREA OVERNIGHT. THE THREAT OF
SHOWERS/ISOLATED STORMS WILL COME TO AN END THIS EVENING THROUGH
EARLY MORNING...FOLLOWED BY SOME CLEARING IN THE DRY SLOT BEHIND
THE FRONT. MODELS CONTINUE TO ADVERTISE SOME COOL AIR OVERNIGHT...
ESPECIALLY WEST WHERE DRIER AIR AND BETTER CLEARING WILL OCCUR.
RECORD LOWS TONIGHT ARE 50 AT CMH...54 AT DAY AND 53 AT CVG. DAY
AND CVG HAVE THE BEST CHANCE OF EITHER TYING OR BREAKING THEIR
RECORD LOWS. WILL RANGE LOWS FROM NEAR 50 WEST TO THE UPPER 50S
EAST.
UPR LVL CLOSED LOW WILL MOVE SLOWLY EAST ACRS THE WRN/CNTRL GREAT
LAKES AREA ON SUNDAY WHILE A RIDGE OF HIGH PRESSURE BUILDS INTO
THE OHIO VALLEY. CAA IN THE WAKE OF THE FRONT WILL RESULT IN SOME
SCT-BKN CUMULUS CLOUDS. CLOUDS SHOULD BE MOST NUMEROUS ACRS THE
FAR NW WHERE EMBEDDED S/WV ENERGY ROTATING AROUND THE LOW COMBINED
WITH WEAK DIURNAL INSTABILITY MAY RESULT IN A FEW SPOTTY SHOWERS
DURING THE AFTN AND EARLY EVENING. HIGHS ON SUNDAY WILL BE UNSEASONABLY
COOL RANGING FROM THE LOWER TO MID 70S. THESE VALUES WILL BE CLOSE
TO RECORD LOW MAXES FOR THE DATE.
FOR SUNDAY NIGHT INTO MONDAY...MOSTLY CLEAR NIGHT/MOSTLY SUNNY
DAY AS HIGH PRESSURE EXPANDS ACRS THE REGION WHILE UPR LVL CLOSED
LOW MOVES OFF TO THE EAST. TEMPERATURES WILL MODIFY SLIGHTLY INTO
THE MID AND UPPER 70S.
FOR THE PERIOD MONDAY NIGHT INTO TUESDAY NIGHT...HIGH PRESSURE
WILL MOVE EAST. MODELS SUGGEST THAT A SLOW MOVING LOW PRESSURE
SYSTEM WILL MOVE TOWARD THE OHIO VALLEY REGION FROM THE CNTRL/SRN
PLAINS. THE APPROACH OF THIS SYSTEM WILL BRING AN INCREASING
CHANCE FOR PCPN...MAINLY FOR LOCATIONS ALONG AND SOUTH OF THE OHIO
RIVER. OVERNIGHT LOWS WILL MODIFY WITH INCREASING CLOUDS. HIGHS
ON TUESDAY WILL RANGE FROM THE UPPER 70S TO AROUND 80 DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
MODELS HAVE SLOWED ON AFOREMENTIONED LOW PRESSURE SYSTEM...SO PCPN
WILL LINGER INTO WEDNESDAY...MAINLY ALONG AND SOUTH OF THE OHIO
RIVER. ON THURSDAY...A SYSTEM EAST OF THE AREA WILL BRING A CHANCE
FOR SHOWERS AND THUNDERSTORMS TO EASTERN PORTIONS OF THE REGION.
BY THURSDAY NIGHT AND CONTINUING INTO FRIDAY...HIGH PRESSURE WILL
BRING DRY CONDITIONS BACK TO THE REGION. THERE WILL BE A SLIGHT
WARMING TREND IN TEMPERATURES THROUGH THE WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LARGE AREA OF LIGHT RAIN WITH SCATTERED EMBEDDED HEAVIER SHOWERS
ARE MOVING NORTHEASTWARD ACROSS THE AREA IN ADVANCE OF APPROACHING
COLD FRONT. AREA OF RAIN IS MOVING A LITTLE FASTER THAN EARLIER
FORECAST AND SHOULD BE GENERALLY EAST OF THE TAFS BETWEEN 14 TO
15Z. HOWEVER, SHOWERS WITH ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP BEHIND THIS RAIN AREA STARTING AROUND 13Z. THE THREAT OF
THUNDERSTORMS END WITH THE PASSAGE OF THE FRONT WHICH WILL BE 17Z
FOR KCVG AND KDAY AND 19Z FOR KCMH. WHILE MOST OF THE
PRECIPITATION WILL PRODUCE WIDESPREAD MVFR THERE WILL BE BRIEF
PERIODS OF IFR DUE TO VSBY IN THE HEAVIER SHOWERS AND THUNDERSTORMS.
ALSO IT SHOULD NOTED FROM THE LAST AVIATION DISCUSSION THAT IFR
CONDITIONS ASSOCIATED WITH CIGS HAVE BEGAN TO DEVELOP JUST TO THE
WEST AND NORTH OF KDAY. KDAY FORECAST HAS BEEN UPDATED TO REFLECT
THIS THREAT.
BEHIND THE FRONT LOW LEVEL DRY AIR WILL BE SLOW TO PUSH IN
ALLOWING FOR SCATTERED SHOWERS AND OCCASIONAL MVFR CIGS LASTING
THROUGH THE AFTERNOON AND INTO THE EVENING BEFORE THEY DISSIPATE.
HOWEVER, MID LEVEL MOISTURE IS EXPECTED TO BE SLOW TO RETREAT FROM
THE AREA SO MID LEVEL CLOUDS ARE CURRENTLY EXPECTED TO PERSIST
THROUGH MOST OF THE NIGHTTIME HOURS.
IN ADVANCE OF THE FRONT SURFACES WINDS WILL BE SOUTHWEST 5-12KT
BECOMING NORTHWEST AROUND 10 -15KT BEHIND THE FRONT.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
514 AM CDT SAT JUL 27 2013
.UPDATE...
12Z TAF DISCUSSION.
&&
.AVIATION...
SCATTERED LIGHT RAIN SHOWERS CONTINUE TO SPREAD ACROSS CKV/BNA
THIS MORNING AND WILL BE NEAR CSV OVER THE NEXT FEW
HOURS...WARRANTING VCSH MENTION AT ALL AIRPORTS. SHORT TERM
GUIDANCE INDICATES A BREAK IN PRECIP BEFORE MORE SCATTERED SHOWERS
DEVELOP THIS AFTERNOON/EVENING AS COLD FRONT APPROACHES. VFR CIGS
ANTICIPATED THROUGH TAF PERIOD WITH LIGHT WEST WINDS BECOMING
NORTHWEST AFTER FROPA.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 342 AM CDT SAT JUL 27 2013/
DISCUSSION...
SHOWERS HAVE BEEN MOVING INTO THE WEST HALF OF MIDDLE TN EARLY
THIS MORNING AS A WEAK H5 TROF MOVES INTO THE REGION. TROF SHOULD
MOVE EAST OF THE REGION WITHIN THE NEXT FEW HOURS AND HRRR SHOWS
THESE SHOWERS ENDING LATER THIS MORNING.
VERY UNUSUAL FORECAST FOR MID SUMMER. H5 CLOSED LOW WILL MOVE
SLOWLY EAST THRU THE GREAT LAKES THIS WEEKEND. ASSOCIATED SFC LOW
WILL HELP BRING A COLD FRONT INTO NW MIDDLE TN LATE TODAY...AND TO
THE REST OF THE AREA BY MIDNIGHT. SCATTERED SHOWERS AND MAYBE A
FEW STORMS WILL REDEVELOP THIS AFTERNOON AND EARLY EVENING AHEAD
OF THE FRONT. RAINFALL AMOUNTS WILL BE LIGHT WITH LESS THAN 1/4
INCH IN MOST AREAS.
COOLER AND DRY WEATHER ON TAP FOR SUN/MON AS SFC RIDGE SETTLES
INTO MID TN. MONDAY MORNING MIN TEMPS COULD APPROACH RECORDS.
GFS GUIDANCE IS AN OUTLIER BY FORECASTING 2 DEGREES COLDER THAN
THE RECORD AT BNA...AND A WHOPPING 5 DEGREES COLDER THAN THE
RECORD AT CSV. SO...LEANED MORE TOWARD THE WARMER AND SEEMINGLY
MORE REASONABLE NAM/ECMWF GUIDANCE.
H5 HEIGHTS REBOUND BY TUESDAY AS GREAT LAKES LOW MOVES FURTHER
AWAY AND RIDGE REBUILDS ACROSS THE SOUTHERN U.S. HOWEVER...GFS AND
ECMWF SHOW WEAK NW FLOW ALOFT WITH A TROF APPROACHING THE MID
STATE TUE/WED...FOLLOWED BY ANOTHER BUT WEAKER COLD FRONT LATE
WEDNESDAY. WITH MEAN RH AND LIFT INCREASING...WILL GO WITH CHANCE
TYPE POPS TUESDAY THRU WEDNESDAY EVENING. GFS AND ECMWF BOTH SHOW
SIGNIFICANT QPF BULLS EYES BUT MAINLY IN SOUTHERN KY.
AFTER THE TROF MOVES AWAY...SOME DRYING IS EXPECTED THURSDAY AND
FRIDAY WITH TEMPS UP A FEW DEGREES AS THICKNESS/HEIGHTS EDGE
UPWARD. RAIN CHANCES MAY INCREASE AGAIN NEXT WEEKEND AS BOTH
MODELS SHOW YET ANOTHER WEAK FRONT MOVING SLOWLY INTO MIDDLE TN
FROM THE NORTH.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
127 PM PDT SAT JUL 27 2013
.SYNOPSIS...
A TROUGH OF LOW PRESSURE OFF THE WEST COAST WILL BRING DRYING
THROUGH MONDAY AND GUSTY WESTERLY WINDS IN THE MOUNTAINS AND
DESERTS. THE MARINE LAYER WILL DEEPEN SLIGHTLY THROUGH SUNDAY...
BRINGING LOW CLOUDS AND FOG INTO THE FAR INLAND VALLEYS EACH
MORNING...AND LIMITED CLEARING ALONG AT THE BEACHES. THE CLOUDS AND
ONSHORE FLOW WILL HOLD DAYTIME TEMPERATURES A BIT BELOW AVERAGE. FOR
NEXT WEEK...SOUTHWEST FLOW ALOFT WILL KEEP THE MONSOON AT BAY...AND
ONSHORE FLOW WILL CONTINUE THE MARINE CLOUDS AND FOG EACH NIGHT AND
MORNING ALONG THE COAST AND INTO THE VALLEYS. SLIGHTLY WARMER FOR
THE LATTER HALF OF THE WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THE STRATUS LAYER EVIDENTLY WAS SOLID THIS MORNING WHICH ALLOWED IT
TO HOLD ON DESPITE THE STRONG MID-SUMMER SUN. LOOKS LIKE IT MAY BE
MAKING UP FOR LOST TIME IN MAY/JUNE. IN ANY CASE IT REMAINS SOLID
ALONG THE COAST AT 1 PM PDT AND WITH UNUSUALLY DEEP PENETRATION INTO
COASTAL SAN DIEGO COUNTY FOR THIS TIME OF YEAR AND HOUR OF THE DAY.
WEAK OFFSHORE GRADIENTS TO NV ARE NOT HELPING...BUT MODERATE ONSHORE
SFC PRESSURE GRADIENTS ARE IN PLACE TO THE LOWER DESERTS.
A WEAK UPPER LOW CENTERED ABOUT 300 MILES W OF POINT CONCEPTION...
WILL DRIFT SLOWLY SE THROUGH MON...WHILE HIGH PRESSURE OVER NM/AZ
SINKS SE. THIS WILL CONTINUE THE DRYING TREND AND SUPPORT THE MARINE
LAYER AND ASSOCIATED STRATUS THROUGH MON. FOR NEXT WEEK...THE
SUBTROPICAL HIGH WILL REMAIN SUBDUED OVER THE RIO GRANDE AREA WHILE
A STRONGER TROUGH MOVES ACROSS THE PACNW. THIS WILL KEEP SOCAL IN A
DRY SW FLOW ALOFT...WHICH SHOULD HOLD THE MONSOON AT BAY.
MAIN FORECAST CONCERN FOR THE DAY WILL BE THUNDERSTORMS AND
COVERAGE. JUST AFTER NOON CU WERE BUBBLING ALONG THE MOUNTAIN CRESTS
AND OVER THE DESERTS. A FEW WERE BIG ENOUGH TO DROP SOME RAIN IN THE
SAN BERNARDINO MTNS. LATEST HRRR MODEL AND THE 18Z RUN OF THE NAM 12
BOTH SHOW PRECIP IN THE MTNS. MOISTURE IS SUFFICIENT...AND MID-LEVEL
WINDS ARE LIGHT ENOUGH TO ENCOURAGE CONVECTION ON THE ELEVATED
TERRAIN IN THESE AREAS...BUT INSTABILITY IS MARGINAL AND THE FLOW IS
WESTERLY ALOFT WHICH SHOULD LIMIT THE EXTENT OF THIS ACTIVITY AS IT
MOVES NE INTO THE DESERTS. CONTINUED DRYING AND WESTERLY FLOW ALOFT
WILL UNDERMINE ANY FURTHER DEVELOPMENT FOR SUNDAY AFTERNOON.
FOR COASTAL AREAS...EXPECT EXTENSIVE NOCTURNAL STRATUS DEVELOPMENT
EACH NIGHT THROUGH TUE...BUT MORE TYPICAL OF LATE JULY...IT SHOULD
BURN OFF BETTER EACH AFTERNOON AS THE INVERSION WEAKENS SLIGHTLY.
SOME BEACHES MAY REMAIN OVERCAST WELL INTO THE AFTERNOONS HOWEVER.
THE MARINE LAYER WILL RETREAT SLIGHTLY DURING THE LATTER HALF OF THE
WEEK FOR FASTER CLEARING AND SLIGHT WARMING. THE ONSHORE PATTERN
WILL SUPPORT GUSTY WINDS THROUGH THE MOUNTAIN PASSES AND INTO THE
DESERTS EACH AFT/EVE...AND HOLD DAYTIME TEMPERATURES A BIT BELOW
AVERAGE THROUGH MID WEEK.
&&
.AVIATION...
2702015Z...COASTS/VALLEYS...LOW CLOUDS BASED 500-900 FT MSL AND TOPS
TO 2000 FT MSL WILL MOVE BACK INTO THE REMAINING COASTAL AIRPORTS
THIS EVENING AROUND 02-06Z. THE LOW CLOUDS SHOULD SPREADING INLAND
OVERNIGHT TO AS FAR AS KRNM...BUT STILL WEST OF KONT. THE LOW CLOUDS
SHOULD CLEAR AROUND 16-17Z INLAND ON SUNDAY...BUT REMAIN BKN-OVC AT
AROUND 1000 FEET MSL COASTAL WATERS AND LOCALLY INLAND. LOCAL
VISIBILITIES BELOW 3SM IN FOG NEAR THE INLAND EDGE OF THE LOW CLOUDS
SUNDAY MORNING. OTHERWISE...SCT-BKN CLOUDS AOA 10000 FT MSL.
MTNS/DESERTS...CU/TCU AND ISOLATED TSTMS OVER THE MTN RIDGES AND
HIGH DESERTS...MAINLY NORTH OF BANNING PASS...ENDING AROUND 28/02Z
THIS AFTERNOON. BASES WILL BE AROUND 10000 FEET WITH TOPS TO 35000
FEET. OTHERWISE...SCT-BKN CLOUDS AOA 10000 FT MSL AND UNRESTRICTED
VSBY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...JAD
AVIATION/MARINE...SMALL
AREA FORECAST DISCUSSION
NWS MIAMI FL
233 PM EDT SAT JUL 27 2013
.DISCUSSION...
NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
ACROSS THE INTERIOR AND EAST COAST DUE TO DAYTIME HEATING...SEA
BREEZE BOUNDARIES AND THE INFLUENCE OF A LOW LEVEL TROUGH. THE
LOW LEVEL TROUGH WILL BEGIN TO SLIDE TO THE NORTHEAST
TONIGHT...PUSHING THE DEEP LOW LEVEL MOISTURE CLOSER TO THE EAST
COAST. THE HRRR AND GFS BOTH SHOW SCATTERED SHOWERS REDEVELOPING
ACROSS THE EAST COAST METRO AREAS AFTER 00Z. THESE SHOWERS MAY
THEN PUSH OFF THE COAST AFTER 06Z. AN UPPER LEVEL SHORTWAVE IS
FORECAST TO DIVE SOUTHEAST INTO NORTHERN FLORIDA OVERNIGHT...AND
THERE MAY BE SOME UPPER DIVERGENCE ACROSS SOUTH FLORIDA AS WELL.
COASTAL CONVERGENCE ALONG THE EAST COAST OF PALM BEACH COUNTY
LATE IN THE NIGHT AND TOWARDS DAYBREAK MAY HELP STORMS REDEVELOP
RIGHT ALONG THE COAST.
THE LOW LEVEL TROUGH WILL CONTINUE TO LIFT NORTHEAST AND THE
SUBTROPICAL RIDGE WILL BEGIN TO NOSE INTO THE REGION DURING THE
DAY ON SUNDAY. SO THE DEEPEST MOISTURE IS EXPECTED TO LIFT OUT OF
SOUTH FLORIDA BY THE AFTERNOON. HOWEVER...THERE WILL STILL BE
UPPER LEVEL DIVERGENCE...AND MOISTURE LEVELS WILL BE NEAR NORMAL.
SO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE
REGION...EXCEPT FOR THE IMMEDIATE GULF COAST. THE MAIN THREAT
AGAIN FOR SUNDAY WILL BE LOCALLY HEAVY RAIN/FLOODING AND GUSTY
WINDS.
THE UPPER TROUGH WILL BEGIN TO LIFT NORTHWARD AS THE SUBTROPICAL
RIDGE BUILDS INTO SOUTH FLORIDA. EASTERLY FLOW WILL RETURN WITH A
MORE TYPICAL PATTERN OF ISOLATED MORNING SHOWERS FOR THE EAST
COAST...AND THEN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
ALONG THE SEA BREEZE BOUNDARIES ACROSS THE INTERIOR AND TOWARDS
THE GULF COAST. THIS PATTERN IS FORECAST TO PERSIST THROUGH THE
MIDDLE OF THE WEEK. TROPICAL STORM DORIAN IS FORECAST TO BECOME A
REMNANT LOW AND THE REMNANTS SHOULD PASS TO THE SOUTH OF SOUTH
FLORIDA ON WEDNESDAY AND THURSDAY. THE SUBTROPICAL RIDGE IS
FORECAST TO SHIFT SLIGHTLY TO THE EAST TOWARDS THE END OF THE WEEK
AS AN UPPER LEVEL TROUGH PUSHES TOWARDS THE EAST COAST AND INTO
THE WESTERN ATLANTIC. RAIN CHANCES MAY THEN INCREASE AGAIN FOR THE
EAST COAST.
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS SOUTH FLORIDA
THROUGH THE AFTERNOON AND EVENING HOURS. THERE WILL BE SOME MVFR
CONDITIONS ACROSS THE EAST COAST TERMINALS DUE TO THE SHOWER AND
THUNDERSTORM ACTIVITY THIS AFTERNOON. WINDS WILL BE SOUTH SOUTHEASTERLY
BETWEEN 5 AND 10 KNOTS BEFORE DIMINISHING LATER THIS EVENING. AT
KAPF, A WEST COAST SEA BREEZE WILL BRING WEST SOUTHWESTERLY WINDS
NEAR 10 KNOTS BEFORE DIMINISHING THIS EVENING.
&&
.MARINE...
WIND AND SEAS WILL REMAIN BELOW CRITICAL LEVELS THROUGH THE PERIOD
OUTSIDE ANY SHOWER OR THUNDERSTORM ACTIVITY WHERE LOCALLY HIGHER
WINDS AND/OR SEAS SHOULD BE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 88 77 89 / 40 50 20 20
FORT LAUDERDALE 76 88 79 89 / 30 50 20 20
MIAMI 76 88 77 90 / 30 50 20 20
NAPLES 77 90 75 92 / 20 20 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
132 PM EDT SAT JUL 27 2013
.PREV DISCUSSION... /ISSUED 1025 AM EDT SAT JUL 27 2013/
UPDATE...
WEAK FRONTAL BOUNDARY SITUATED ACROSS THE MID MISSISSIPPI RIVER
VALLEY THIS MORNING. 500MB ANALYSIS SHOWS A SHEAR AXIS ACROSS
WESTERN GA. A BROKEN LINE OF SHOWERS HAS FORMED ALONG AND JUST
AHEAD OF THIS FEATURE. THE LATEST RUNS OF THE HRRR SEEM TO HANDLE
THIS WELL...SO HAVE RE-ORIENTED POPS ACCORDINGLY.
IN ADDITION...DUE TO THE THICK CLOUD COVER AND PRECIP...HAVE DECREASED
MAX TEMPS ACROSS THE NORTHERN PART OF THE STATE A FEW DEGREES.
PREV DISCUSSION... /ISSUED 748 AM EDT SAT JUL 27 2013/
PREV DISCUSSION... /ISSUED 434 AM EDT SAT JUL 27 2013/
SHORT TERM /TODAY THROUGH SUNDAY/...
PRIMARY CONCERN IS LIKELIHOOD OF CONVECTION THIS AFTERNOON AND
EVENING. APPROACHING SHORT WAVE TROUGH JUST WEST OF CWA THIS
MORNING YET MEAN RH AND VERTICAL MOTION LACKING. IR/WV IMAGERY
ALSO CONFIRMING THIS BAND OF DRIER AIR CURRENTLY ACROSS WESTERN GA
UP THROUGH ERN TN. DEEPER MOISTURE JUST WEST OF TROUGH AXIS IN
MS/AL. THIS MOISTURE WILL PUSH INTO CWA THIS AFTERNOON AND EVENING
SO EXPECT DEVELOPMENT OF SCT TSRA AROUND 18-20Z WITH 30-50PCT
COVERAGE...GREATEST OVER ERN AND WC/SW GA. A FEW STORMS COULD
APPROACH SVR CRITERIA BUT MLCAPE AND THETA-E LAPSE RATES DO NOT
WARRANT ANYTHING MORE INTENSE THAN THAT. OVER NORTH AND MUCH OF
MIDDLE GA...GFS HAS VERY LITTLE CAPE DUE TO SLIGHTLY DRIER LOW
LEVELS AND THICKER MID CLOUDS. AFTER SOME PATCHY FOG AGAIN SUNDAY
MORNING...SHOULD BE EVEN LESS COVERAGE OF STORMS OVER NORTH AND
WEST GA SUNDAY PM AS SHORT WAVE PASSES AND DRIER AIR PUSHES
FURTHER IN. HAVE KEPT POPS IN CHC CATEGORY OVER SOUTH AND EAST
COUNTIES BUT MUCH OF NORTH GA WILL BE POP-FREE.
WENT ABOVE MAX TEMP GUIDANCE FOR SAT AND SUN BASED ON LESS CLOUDS/
PRECIP THAN PREV THOUGHT. USED BLEND OF 30 DAY BIAS CORRECTED TEMPS
WITH GREATER WEIGHT TOWARD THE MAV FOR MIN TEMPS.
SNELSON
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
WITH SFC RIDGING BUILDING INTO THE CWA NEAR THE BEGINNING OF THE
LONG TERM AND NO STRONG WAVES PEGGED IN THE UPPER LEVELS...THIS MAY
PROVIDE A SHORT BREAK IN THE HIGHER THAN CLIMO POPS. WITH SFC RIDGE
CENTERED OVER THE OHIO VALLEY ON MONDAY...THE GFS KEEPS THE CWA DRY
WHEREAS THE ECMWF LINGERS SOME BETTER MOISTURE ACROSS CENTRAL
GEORGIA. FORECAST IS NEAR A BLEND OF THE TWO...WITH ONLY A SLIGHT
CHANCE MENTIONED ACROSS CENTRAL GEORGIA FOR THE AFTERNOON. WITH A
SERIES OF SHORTWAVES MOVING THROUGH MID-WEEK...WILL SEE A RETURN
OF THE ABOVE NORMAL POPS. GFS HAS BEEN FAIRLY CONSISTENT WITH
TIMING BETWEEN LAST NIGHT AND TONIGHT WHEREAS THE ECMWF HAS HAD
SOME RUN TO RUN DIFFERENCES. 00Z ECMWF HAS COME INTO BETTER
AGREEMENT AGAIN WITH THE 00Z GFS AS OPPOSED TO THE 12Z ECMWF. MAIN
IMPACT WITH THESE SHORTWAVES WILL BE AN INCREASE IN POPS FOR THE
WEDNESDAY TO THURSDAY TIME FRAME WITH THE BEST CHANCES ACROSS
NORTH GEORGIA ON WEDNESDAY. GIVEN SOME CONSISTENCY IN TIMING WITH
THE GFS...HAVE GONE AHEAD AND INTRODUCED LIKELY POPS FOR FAR NORTH
GEORGIA ON WEDNESDAY. PLENTY OF INSTABILITY WITH THE SYSTEM...BUT
SHEAR IS LACKING. STILL WITH INSTABILITY ALONE...ITS ENOUGH THAT
SOME OF THE STORMS COULD BECOME STRONG. GFS AND ECMWF ARE
CONSISTENT WITH HIGHER RAINFALL AMOUNTS ACROSS NORTH GEORGIA WITH
BOTH MODELS DEPICTING JUST UNDER 2 INCHES IN THE WEDNESDAY/THURSDAY
TIME FRAME. BY FRIDAY...UPPER DISTURBANCE IS EAST OF THE AREA AND
THAT WILL BRING US BACK INTO A MORE TYPICAL SUMMERTIME
PATTERN...AT LEAST IN TERMS OF CONVECTION.
11
&&
.AVIATION...
18Z UPDATE...
LIGHT SHOWERS ARE APPROACHING THE AIRPORT AT ISSUANCE TIME.
HOWEVER...ANY PRECIP FALLING IS VERY LIGHT IN NATURE AND BARELY
MEASURING. DO THINK THE CHANCES FOR THUNDER INCREASE A LITTLE BIT
DURING THE MID AFTERNOON...BUT INSTABILITY IS LIMITED AND ANY
THUNDERSTORMS THAT DEVELOP WILL BE ISOLATED. MODELS ARE FORECASTING
LOW CIGS AGAIN TONIGHT. CIGS COULD REACH 006 AT ATL FOR A BRIEF
PERIOD OF TIME. FROPA TOMORROW WITH A WIND SHIFT TO THE W/NW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 69 88 65 / 50 30 20 10
ATLANTA 83 69 86 66 / 40 30 20 10
BLAIRSVILLE 77 63 82 57 / 40 30 10 10
CARTERSVILLE 83 66 86 60 / 40 30 10 10
COLUMBUS 88 72 89 70 / 40 30 30 20
GAINESVILLE 82 68 85 64 / 40 30 20 10
MACON 88 69 90 69 / 50 30 40 20
ROME 84 66 86 59 / 30 30 10 10
PEACHTREE CITY 85 67 86 62 / 40 30 20 10
VIDALIA 88 72 89 72 / 50 30 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1232 PM CDT SAT JUL 27 2013
.DISCUSSION...
ISSUED 1033 AM CDT SAT JUL 27 2013
UNSEASONABLY COOL AIRMASS HAS SETTLED INTO CENTRAL ILLINOIS THIS
MORNING...WITH 15Z/10AM TEMPS RANGING FROM THE LOWER 60S NORTH OF
PEORIA TO THE LOWER 70S ALONG/SOUTH OF I-70. SKIES STARTED OUT
CLEAR...BUT HAVE BECOME PARTLY SUNNY AS SCT-BKN DIURNAL CU HAVE
DEVELOPED ACROSS THE AREA. VERY COLD TEMPS ALOFT ASSOCIATED WITH
DEEP UPPER LOW SPINNING OVER THE WESTERN GREAT LAKES WILL SUPPORT
STEEP MID-LEVEL LAPSE RATES AND PLENTY OF CLOUD DEVELOPMENT. MAY
EVEN SEE SOME SPRINKLES FROM TIME TO TIME...AS FORECAST SOUNDINGS
SHOW A 3000 TO 4000-FOOT THICK CLOUD LAYER ENHANCED BY A SHORT-WAVE
TROUGH ROTATING ACROSS NORTH-CENTRAL ILLINOIS. HRRR SUGGESTS
SCATTERED SPRINKLES AHEAD OF THIS FEATURE AS WELL...AND HAVE SEEN
SOME WEAK RETURNS UPSTREAM ON KDVN RADAR OVER THE PAST HOUR.
HAVE THEREFORE UPDATED THE FORECAST TO INCREASE CLOUD COVER AND
ADD SCATTERED SPRINKLES DURING THE LATE MORNING INTO THE
AFTERNOON. ALSO NUDGED HIGHS UP A DEGREE OR TWO...AS JULY SUN HAS
WARMED READINGS A BIT FASTER THIS MORNING THAN PREVIOUSLY THOUGHT.
ZONE UPDATE HAS ALREADY BEEN ISSUED.
BARNES
&&
.AVIATION...
ISSUED 1232 PM CDT SAT JUL 27 2013
AFTER A PERIOD OF MVFR CEILINGS THIS MORNING...CLOUD BASES HAVE
GRADUALLY RISEN INTO THE VFR CATEGORY EARLY THIS AFTERNOON.
FORECAST SOUNDINGS SUGGEST THIS WILL CONTINUE THROUGH THE BALANCE
OF THE AFTERNOON BEFORE DIURNAL CLOUD COVER DISSIPATES TOWARD
SUNSET. BASED ON LATEST SATELLITE IMAGERY...IT APPEARS THE
THICKEST CLOUD COVER IS CURRENTLY LOCATED OVER EASTERN IOWA INTO
NORTHERN ILLINOIS. AS A RESULT...WILL MAINTAIN BROKEN VFR CEILINGS
AT BOTH KPIA AND KBMI UNTIL 01Z. FURTHER SOUTH/EAST...WILL SCATTER
CLOUDS OUT A BIT EARLIER AT 23Z. AN AREA OF CLOUDS OVER EASTERN
MINNESOTA INTO WISCONSIN WILL CONTINUE TO DROP S/SE TONIGHT. MODEL
RH PROFILES SUGGEST MUCH OF THIS WILL REMAIN JUST N/NE OF THE KILX
CWA...HOWEVER WILL INCLUDE SCT CLOUD COVER THROUGH THE ENTIRE NIGHT
AS FAR SOUTH AS KPIA AND KBMI AS THIS MOISTURE GRAZES THE AREA.
ELSEWHERE...CLEAR SKIES WILL PREVAIL AFTER SUNSET. NORTHWESTERLY
WINDS WILL INITIALLY GUST TO BETWEEN 15 AND 20KT AT TIMES THIS
AFTERNOON...THEN WILL BACK TO WESTERLY AND DECREASE TO AROUND 5KT
TONIGHT.
BARNES
&&
.PREV DISCUSSION...
ISSUED 303 AM CDT SAT JUL 27 2013
SHORT TERM...TODAY THROUGH MONDAY
COLD FRONT AT 07Z HAD CLEARED ALL BUT OUR SOUTHEAST FEW COUNTIES
WHILE SKIES CLEARED FOR MUCH OF THE CWA. LIGHT W/NW WINDS WERE
SLOWLY BRINGING IN COOLER AND DRIER AIR WITH MID 50S DEW POINTS
NOTED WEST OF THE IL RIVER. UNSEASONABLY COLD AIRMASS POISED TO
OUR NORTHWEST...WITH A FALL-LIKE +2C 850MB 00Z TEMPERATURE AT
INTERNATIONAL FALLS. THIS MODIFIED CANADIAN AIRMASS WILL SHIFT
SOUTHEAST ACROSS THE REGION THIS WEEKEND ON THE BACK SIDE OF A
STRONG CLOSED 500MB LOW DRIFTING ACROSS THE GREAT LAKES. STEEP LOW
LEVEL LAPSE RATES AND CYCLONIC FLOW SHOULD ALLOW PLENTY OF DIURNAL
CU FORMATION TODAY AND SUNDAY. WITH DEEPER MOISTURE STAYING
FARTHER NORTHEAST FEEL ANY SPRINKLES WILL BE TOO ISOLATED TO
MENTION IN FORECAST. MAIN STORY THROUGH SUNDAY WILL BE UNUSUALLY
COOL TEMPERATURES FOR LATE JULY. 850MB READINGS ARE FORECAST TO DIP AS
LOW AS +5-7C OVER THE NORTHERN CWA LATER TODAY AND TONIGHT. THUS
RECORD COOL HIGHS TODAY /GENERALLY LOWER 70S/ AND RECORD LOWS
TONIGHT /NEAR 50F/ WILL BE IN JEOPARDY. SEE CLIMATE SECTION BELOW
FOR SPECIFIC NUMBERS FOR OFFICIAL CLIMATE SITES.
TEMPERATURES WILL BEGIN TO MODERATE LATER SUNDAY AND ESPECIALLY
MONDAY AS HIGH PRESSURE SHIFTS SOUTH OF THE OHIO VALLEY AND THE
NEXT LOW DEVELOPS OVER THE CENTRAL PLAINS. A WARM FRONT LIFTING
NORTHEAST ACROSS MISSOURI COULD SPREAD SCATTERED THUNDERSTORMS AS
FAR EAST AS WESTERN IL LATE MONDAY AFTERNOON WITH BETTER CHANCES
MONDAY NIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
00Z MODELS HAVE COME INTO A BIT BETTER AGREEMENT IN HANDLING THE CENTRAL
PLAINS LOW WHICH IS FORECAST TO TRACK EAST TOWARDS THE CENTRAL
MISSISSIPPI RIVER/LOWER OHIO RIVER VALLEY REGION BY LATE TUESDAY.
NAM IS FARTHEST NORTH/QUICKEST WHILE ECMWF HAS TRENDED FARTHER
NORTH AND NOW LOOKS SIMILAR TO CURRENT AND PREVIOUS GFS SOLUTIONS.
THUS WILL EXPAND LIKELY POPS NORTH FOR MUCH OF THE SOUTHERN HALF
OF THE CWA MONDAY NIGHT AND TUESDAY WITH CHANCE POPS FARTHER NORTH.
MOISTURE RETURN SOUTH OF THE SYSTEM AND FORCING SUGGEST A MODERATE
1-2 INCH QPF EVENT WHERE EVENTUAL PRECIP PATH DOES LAY OUT.
WED-FRI APPEARS GENERALLY DRY WITH LOW AMPLITUDE NW FLOW ALOFT AND
TEMPERATURES RETURNING TO NEAR NORMAL. A WEAK UPPER WAVE IS
PROGGED TO MOVE THROUGH IN THE WED/WED NIGHT TIME FRAME BUT WITH
LIMITED FORCING THIS FAR SOUTH ONLY HAVE SLIGHT CHANCE POPS. A
MORE RESPECTABLE SYSTEM MAY PUSH EAST INTO THE MIDWEST TOWARDS THE
END OF THE WEEK. QUITE A LARGE MODEL SPREAD IN TIMING AND LOCATION
SO CURRENT LOW CHANCE POPS ON FRIDAY LOOK GOOD.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
116 PM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT JUL 27 2013
AN ABNORMALLY COOL AND DRY AIRMASS IS CURRENTLY IN PLACE OVER THE
CENTRAL AND NORTHERN PLAINS IN THE FORM OF A SURFACE RIDGE WHICH
EXTENDS FROM SOUTHERN KANSAS NORTHWARD THROUGH NEBRASKA AND INTO THE
NORTHERN PLAINS. THIS AIRMASS IS CHARACTERIZED BY TEMPS IN THE UPPER
40S TO MID 50S ACROSS EASTERN NEBRASKA AND IN THE UPPER 50S TO LOWER
60S THROUGHOUT EASTERN KANSAS. EXPECT THESE TEMPS TO CONTINUE TO
DROP THROUGH THE REST OF THE OVERNIGHT HOURS AND SETTLE AROUND THE
MID TO UPPER 50S FOR OUR FORECAST AREA. RADAR TRENDS SHOW A VERY
WEAK COMPLEX OF SHOWERS AND THUNDERSTORMS IN CENTRAL NEBRASKA. THIS
COMPLEX LOOKS TO BE ASSOCIATED WITH SOME MODERATE ISENTROPIC LIFT
ALONG THE 310K THETA E SURFACE. SOMEWHAT SURPRISING IS THE AMOUNT OF
LIGHTNING DETECTED WITH THESE STORMS AS RAP SOUNDINGS ONLY INDICATE
AROUND 100-200 J/KG OF ELEVATED INSTABILITY FOR THESE STORMS TO WORK
WITH. NONETHELESS HAVE GONE WITH A CHANCE OF ISOLATED THUNDERSTORMS
FOR THE NORTH CENTRAL AND CENTRAL PART OF THE STATE...INCLUDING THE
FAR WESTERN ZONES OF THE FORECAST AREA THROUGH THE MORNING
HOURS...BEFORE GRADUALLY DISSIPATING DURING THE AFTERNOON. WITH THE
COOLER/DRIER AIRMASS IN PLACE OVER THE FORECAST AREA EXPECT TEMPS TO
BE WELL BELOW SEASONAL NORMS...WITH HIGHS REACHING THE MID TO UPPER
70S...WITH PERHAPS A FEW AREAS REACHING 80 DEGREES. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING AS ANOTHER ROUND OF WARM AIR ADVECTION SHOWERS
COMMENCE ACROSS WESTERN AND CENTRAL KANSAS. EXPECT THESE SHOWERS TO
SPILL INTO OUR AREA AND SPREAD EASTWARD OVERNIGHT SATURDAY NIGHT
INTO SUNDAY MORNING. ANOTHER COOL NIGHT IS IN STORE FOR THE AREA ON
SATURDAY NIGHT...AS LOWS WILL LIKELY DROP INTO THE LOWER TO MID 50S
ACROSS THE EASTERN HALF OF THE CWA...WHILE AREAS IN THE WESTERN HALF
WILL STAY IN THE MID TO UPPER 50S.
.LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 324 AM CDT SAT JUL
27 2013
MOISTURE AND PRECIP SLOWLY INCREASE FROM WEST TO EAST ACROSS
EASTERN KANSAS ON SUNDAY...BECOMING LIKELY SUNDAY NIGHT INTO
MONDAY. HIGHS SUNDAY WITH INCREASING CLOUD COVER AND RAIN CHANCES
EXPECTED TO BE IN THE MIDDLE 70S FOR MUCH OF THE AREA. BY 12Z
MONDAY...SURFACE LOW OVER THE TX PANHANDLE GETS A BOOST FROM A
PASSING SHORTWAVE TROF ROLLING OFF THE HIGH PLAINS...INCREASING
MOISTURE ADVECTION AND THE LLJ AND FOCUSING PRECIPITATION ACROSS
EASTERN KANSAS. STILL SOME DISCREPANCIES AS TO HOW FAR NORTH THE
BRUNT OF THE RAIN WILL FALL...WITH NAM ALONG THE I70 CORRIDOR AND
EC FARTHER SOUTHWARD TOWARD SE KS. WILL FAVOR POPS OVER THE
SOUTHERN HALF OF THE AREA AND NOTE THAT PRECIP AMOUNTS COULD BE A
FEW INCHES OR MORE IN SOME LOCATIONS. NO WATCH AT THIS TIME BUT
WILL NEED TO MONITOR EVOLUTION FOR POSSIBLE LOCALIZED FLOODING
CONCERNS ON MONDAY.
SYSTEM MOVES EAST BY MONDAY NIGHT AND EXPECT PRECIP TO END QUICKLY
W TO E EARLY TUESDAY. MAINLY DRY CONDITIONS FORECAST THROUGH
THURSDAY. ZONAL FLOW SLOWLY TRANSITIONS TO WNW FLOW AROUND THE
SOUTHERN UPPER HIGH...AND THIS SLOWLY WARMS TEMPERATURES INTO THE
LOWER 80S TUESDAY TO THE UPPER 80S BY THURSDAY. MAY SEE THE NEXT
CHANCE FOR RAINFALL ON FRIDAY AS ANOTHER SW TROF TRAVERSES THROUGH
THE FLOW BUT HAVE NOT GONE TOO HIGH ON CHANCES THIS FAR OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 106 PM CDT SAT JUL 27 2013
ISOLATED SHOWERS WILL LINGER NEAR THE TAF SITES UNTIL AROUND
20Z...OTHERWISE EXPECT VFR AND DRY CONDITIONS THROUGH THE PERIOD.
CONFIDENCE REMAINS TOO LOW TO INSERT BACK INTO TAFS THIS FCST FOR
KTOP/KFOE...BUT HIGHER POTENTIAL AT KMHK WARRANTS ADDING VCSH BACK
INTO FCST BY 14Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEIGHTON
LONG TERM...67
AVIATION...63
AREA FORECAST DISCUSSION
NWS JACKSON KY
637 PM EDT SAT JUL 27 2013
.UPDATE...
ISSUED AT 637 PM EDT SAT JUL 27 2013
HAVE MODIFIED POP GRIDS FOR TONIGHT INTO SUNDAY MORNING...
INCORPORATING SOME TRENDS FROM THE RUC AND HRRR. THE SHORT TERM RAPID
UPDATE MODELS ARE SHOWING SHOWERS AND POSSIBLY THUNDERSTORMS
DEVELOPING ALONG AND JUST AHEAD OF THE COLD FRONT AS IT MOVES
IN...AND RADAR TRENDS EARLY THIS EVENING SEEM TO LEND SOME SUPPORT
TO THIS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 245 PM EDT SAT JUL 27 2013
SHOWERS AHEAD OF THE COLD FRONT CONTINUE TO CROSS EASTERN KENTUCKY.
FRONT SCHEDULED TO CROSS TONIGHT AND SHOULD BE EAST OF THE STATE BY
SUN MORNING. THEN HIGH PRESSURE BUILDS DOWN FROM CANADA WITH A DRIER
AND COOLER AIR MASS. A FEW SHOWERS THIS EVENING COULD PRODUCE
THUNDER...BUT MOST SHOULD BE JUST LIGHT RAIN. RAINFALL TOTALS WILL
GENERALLY BE LESS THAN A QUARTER OF AN INCH. COOLER AIR WILL BE SLOW
TO INVADE SO OVERNIGHT LOWS WILL DROP TO THE 50S BUT WITH ENOUGH
REMAINING MOISTURE THAT VALLEY FOG MAY STILL BE A PROBLEM. THE COOLER
AIR WILL BATTLE ADDITIONAL SUNSHINE TO HOLD SUNDAY HIGHS TO THE UPPER
70S AND THEN WITH THE INFLUX OF DRIER AIR SUNDAY NIGHT LOWS WILL FALL
INTO THE LOWER 50S. EVEN A FEW UPPER 40S ARE NOT OUT OF THE QUESTION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 249 PM EDT SAT JUL 27 2013
PERIOD WILL START OFF WITH UPPER LEVEL CLOSED LOW LIFTING TO THE NE
AND SURFACE HIGH PRESSURE SITTING OVERHEAD OF THE OHIO VALLEY. WITH
A STRONG JET IN THE UPPER LEVELS PULLING IN DRY AIR FROM THE
NE...ALONG WITH LIGHT NE WINDS AT THE SURFACE...EXPECT TEMPERATURES
TO REMAIN SLIGHTLY BELOW NORMAL AND HUMIDITY LEVELS TO BE LOW.
OVERALL IT WILL BE A BEAUTIFUL DAY WITH HIGH TEMPERATURES STILL
EXPECTED TO ONLY REACH NEAR 80...AND SLIGHTLY LOWER IN THE HIGHER
HILLS ALONG THE KY/VA BORDER. OVERNIGHT TEMPS WILL ONCE AGAIN DROP
DOWN TO BELOW NORMAL...POSSIBLY DROPPING LOWER THAN THE 60 DEGREE
MARK IN MANY LOCATIONS.
BY TUESDAY...HIGH PRESSURE OVER ERNY KY WILL PERSIST IN THE
MORNING/EARLY AFTERNOON WITH SIMILAR TEMPS AND LOW HUMIDITY VALUES.
BY LATE AFTERNOON/EVENING HOWEVER...THINGS WILL BEGIN TO CHANGE.
WHILE THE 500MB LOW CONTINUES TO LIFT NE...MUCH OF THE CONUS WILL
FIND ITSELF IN A MORE ZONAL FLOW. WITHIN THIS ZONAL FLOW A SHORTWAVE
WILL TRAVEL EASTWARD FROM THE COLORADO MOUNTAINS ON SUNDAY TO THE
OHIO VALLEY BY TUESDAY EVENING. THIS WILL TRANSLATE TO A SURFACE
BOUNDARY WHICH WILL PROGRESS WITH THE SYSTEM...AND TRAVERSE EASTERN
KY TUESDAY NIGHT/WEDNESDAY. AS HAS BEEN THE CASE IN PREVIOUS
FORECASTS...MODELS ARE STILL HAVING A HARD TIME COMING INTO
AGREEMENT ON THE EXACT TIMING OF THIS FRONTAL PASSAGE...ALONG WITH
THE TIMING AND COVERAGE OF THE ASSOCIATED CONVECTION. THE LAST TWO
RUNS OF THE GFS HAS SLOWED DOWN THE CONVECTION/S ARRIVAL IN EASTERN
KY UNTIL LATE WEDNESDAY NIGHT/EARLY WEDNESDAY MORNING. THE GEM IS
AGREEING MORE WITH THE GFS...BUT THE 0Z RUN OF THE ECMWF IS BOTH
FASTER IN TIMING AND HIGHER IN COVERAGE AND PRECIP AMOUNTS. SINCE
THIS IS DAY 4...THERE IS STILL PLENTY OF TIME FOR CHANGE AND BETTER
AGREEMENT WITH FUTURE MODEL RUNS...SO WILL CONTINUE WITH A CONSENSUS
AT THIS TIME ON PRECIP TIMING AND COVERAGE. REGARDLESS...NAM AND GFS
MODELS ARE IN GOOD AGREEMENT THAT HIGH LEVEL CLOUDS WILL START
MOVING ACROSS THE AREA AS EARLY AS LATE MONDAY NIGHT/TUESDAY
MORNING...WELL BEFORE ANY PRECIP STARTS. WINDS WILL ALSO TURN MORE
SRLY BY AFTERNOON...PULLING IN WARMER MOISTER AIR FROM THE SOUTH.
NOT ONLY WILL THIS HELP WITH THE PRECIP CHANCES TUESDAY
NIGHT/WEDNESDAY...BUT IT WILL ALSO MEAN THE RETURN OF A MORE HUMID
SUMMER AIR MASS.
AS FAR AS INSTABILITY DURING THE DAY WEDNESDAY...THERE REALLY ISN/T
MUCH. WINDS ARE SHOWING A DECENT VEERING PATTERN...ESPECIALLY IN THE
LOW LEVELS...BUT THE LAPSE RATES AND RESULTING POSITIVE ENERGY ARE
JUST NOT IMPRESSIVE. THE MAIN CONCERN IS THE AMOUNT OF MOISTURE
ASSOCIATED WITH THIS SYSTEM...WITH A SATURATED ATMOSPHERE AND PWAT
VALUES NEARING 1.5 TO 2.0 INCHES EVERY SIX HOURS ACCORDING TO THE
LATEST GFS RUN. WHILE AN EMBEDDED THUNDERSTORM IS NEVER OUT OF THE
QUESTION THIS TIME OF YEAR IN A MOIST AND WARM ENVIRONMENT...THE
MAIN CONCERN ON WEDNESDAY SHOULD JUST BE THE AMOUNT OF RAIN ACROSS
THE REGION AND THE POSSIBILITY FOR FLASH FLOODING AS A RESULT.
THE SURFACE BOUNDARY WILL CONTINUE TO PUSH OFF TO THE SE DURING THE
DAY THURSDAY...WITH PRECIP CHANCES EXPECTED TO CONTINUE THROUGHOUT
THE MORNING AND COME TO AN END DURING THE LATE AFTERNOON/EVENING
HOURS AS DRY AIR ALOFT BEGINS TO WORK IN ACROSS THE REGION AND MAKE
IT/S WAY DOWN TO THE SURFACE. FOR A FEW HOURS LATE THURS MORN/EARLY
AFTERNOON...DRY AIR ALOFT...LLVL MOISTURE...AND STEEPER LAPSE
RATES...WILL TRIGGER A BETTER CHANCE FOR SOME ISL/SCT THUNDERSTORM
DEVELOPMENT /ESPECIALLY IN THE EAST/. THE WINDOW FOR THIS HAPPENING
WILL BE CLOSED PRETTY QUICKLY THOUGH AS DRY AIR MAKES ITS WAY TO THE
SURFACE AND A LLVL INVERSION FORMS BY 0Z FRIDAY. THIS INVERSION AND
DRY AIR /HIGH PRESSURE/ WILL REMAIN IN PLACE THROUGHOUT THE DAY
FRIDAY AND INTO FRIDAY NIGHT. TEMPERATURES WILL BE ON AN INCREASING
TREND TUESDAY THROUGH THE END OF THE WEEK...WITH FRIDAY HAVING THE
HOTTEST TEMPS FORECASTED OF ANY OTHER DAY DURING THE FORECAST
PERIOD. HIGHS WILL TOP OUT IN THE MID 80S ON THIS DAY. BUT WITH A
DRY AIR MASS OVERHEAD AND WINDS ALOFT OUT OF THE NE...EXPECT THE
HUMIDITY LEVELS TO REMAIN AT BAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1246 PM EDT SAT JUL 27 2013
A COLD FRONT WILL PUSH ACROSS KENTUCKY TONIGHT...PRODUCING SOME
5-6KFT CIGS TODAY. SOME LIGHT SHOWER ACTIVITY SHOULD INTENSIFY THIS
AFTERNOON WITH A THUNDERSTORM POSSIBLE. GOING TO LEAVE VCTS IN FOR
THE AFTERNOON WITH LOW CONFIDENCE IN ANY THUNDERSTORMS IMPACTING THE
TAF SITES. GFS LAMP GUIDANCE REALLY HAMMERING THE FOG TONIGHT...BUT
WITH DRY AIR ADVECTION BEHIND THE FRONT COMBINED WITH SOME WEAK
NORTHWEST WINDS...OPTED TO GO NO LOWER THAN MVFR VIS BUT COULD SEE
IFR CIGS IN LOW STRATUS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...DUSTY
LONG TERM...JMW
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS BILLINGS MT
251 PM MDT SAT JUL 27 2013
.SHORT TERM...VALID FOR SUN AND MON...
ACTIVE WEATHER IS EXPECTED THE NEXT FEW DAYS AS FLOW ALOFT BECOMES
SOUTHWEST AND SEVERAL WEAK SHORT WAVES CROSS THE REGION.
TONIGHT...WE WILL CONTINUE THE RED FLAG WARNING FOR PARTS OF SOUTH
CENTRAL MT THROUGH 06 UTC. CONVECTION IS SLOWLY DEEPENING OVER THE
REGION AS OF MID AFTERNOON...AND BOTH THE 17 UTC HRRR AND NAM FROM
18 UTC CALL FOR AT LEAST A SCATTERED COVERAGE OF STORMS ACROSS ALL
OF SOUTH CENTRAL MT AS FAR EAST AS BILLINGS THIS EVENING. THE RISK
OF DRY LIGHTNING REMAINS HIGH ENOUGH TO CONTINUE THE RED FLAG EVEN
THOUGH BOUNDARY LAYER HUMIDITIES HAVE STAYED ELEVATED ACROSS PARTS
OF THE GALLATIN NATIONAL FOREST SO FAR TODAY THANKS TO CLOUDS. THE
INVERTED-V SIGNATURES ON FORECAST SOUNDINGS ARE ALSO STILL PRESENT
AND THUS SUGGEST POTENTIALLY GUSTY AND ERRATIC THUNDERSTORM WINDS.
THE CHANCE OF STORMS WILL CONTINUE OVERNIGHT AND GRADUALLY SPREAD
INTO SOUTHEASTERN MT AFTER 06 UTC.
SUN...THE LOWER AND MID 50S F DEWPOINTS OBSERVED ACROSS EASTERN CO
AND SOUTHEASTERN WY SAT AFTERNOON SHOULD GET DRAWN NORTH AND REACH
SOUTHERN MT ON SUN. A SURFACE TROUGH WILL BE CENTERED ACROSS SOUTH
CENTRAL MT WITH AN ATTENDANT WIND SHIFT...AND THAT WILL CONTRIBUTE
TO FOCUSED THUNDERSTORM ACTIVITY SUPPORTIVE OF SOME LIKELY POPS IN
PLACES LIKE SHERIDAN AND MILES CITY. HOWEVER...CONVECTION COULD BE
IN THE CARDS ANYWHERE GIVEN AGITATED SOUTHWEST FLOW AT 500-HPA AND
UPSLOPE LOW-LEVEL FLOW BEHIND THE TROUGH OVER SOUTH CENTRAL MT. IT
LOOKS LIKE A SOLID 500 J/KG OF MLCAPE WILL BE IN PLACE...AND THERE
SHOULD BE POCKETS OF MLCAPE CLOSER TO 1000 J/KG. FORECAST SOUNDING
PROFILES SHOW A RELATIVE WEAKNESS IN WINDS FROM ABOUT 700- TO 500-
HPA...BUT STRONGER FLOW ABOVE THAT STILL YIELDS 30 TO 40 KT OF 0-6
KM BULK SHEAR. GIVEN FAVORABLY STEEP MID-LEVEL LAPSE RATES...THERE
IS POTENTIAL FOR ISOLATED SEVERE STORMS UNTIL NOCTURNAL COOLING IS
ABLE TO REDUCE BOUNDARY LAYER BUOYANCY BY LATE EVENING. WE DECIDED
TO MENTION THAT POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK. NOTE
THAT STORMS SUN SHOULD BE WETTER THAN SAT WITH HIGHER PRECIPITABLE
WATER VALUES AND GREATER BOUNDARY LAYER HUMIDITY. IN FACT...WE MAY
HAVE LOCALLY HEAVY RAIN WITH STORMS ALONG THE SURFACE TROUGH WHERE
PRECIPITABLE WATER VALUES MAY EXCEED AN INCH.
MON...THE SURFACE TROUGH WILL MOVE INTO THE DAKOTAS...BUT WE STILL
NEED CHANCE-STYLE POPS ACROSS THE WHOLE AREA IN RESPECT TO UPSLOPE
LOW-LEVEL FLOW ON NORTH-NORTHEAST WINDS BENEATH THE WEST-SOUTHWEST
FLOW ALOFT. A COOLING TREND WILL BE IN PLACE...AND IN FACT WE HAVE
SOME CONCERN THAT THIS SCENARIO COULD BRING COOLER-THAN-ADVERTISED
HIGHS TO THE AREA...ESPECIALLY IF ANY STRATUS AND/OR DEBRIS CLOUDS
FROM CONVECTION HAMPER DIABATIC HEATING AFTER 18 UTC. OUR FORECAST
IS NEAR THE CONSENSUS OF 12 UTC NON-MOS GUIDANCE /WHICH IS USUALLY
A GOOD BET TO PICK UP ON A SITUATION LIKE THIS/ THOUGH...SO WE DID
NOT MAKE ANY CHANGE TO GOING HIGHS FOR NOW. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
EXTENDED PACKAGE LOOKS TO BE IN GOOD SHAPE SO HAVE ONLY MADE A
FEW MINOR ADJUSTMENTS. OVERALL PATTERN LOOKS TO BE UNSETTLED
THROUGH THE UPCOMING WEEK. MODELS ARE MAINLY IN AGREEMENT IN
PLACING A LARGE UPPER LOW OVER THE PACIFIC NORTHWEST THROUGH THE
WEEK RESULTING IN AN UNSETTLED SOUTHWEST FLOW ALOFT ACROSS OUR
FORECAST AREA. SEVERAL DISTURBANCES WILL MOVE OVERHEAD AS WELL BUT
TIMING THIS FAR OUT IS DIFFICULT. AT THIS TIME...THE
WEDNESDAY/THURSDAY TIMEFRAME LOOKS TO HAVE THE HIGHEST CHANCES FOR
MORE WIDESPREAD THUNDERSTORM ACTIVITY. HIGH PRESSURE RIDGING AND
HIGHEST HEIGHTS WILL BE SHUNTED TO THE SOUTH OF OUR STATE. THIS
COMBINED WITH PERIODS OF CLOUDS AND THUNDERSTORM ACTIVITY WILL
RESULT IN DAYTIME TEMPERATURES AT OR SLIGHTLY BELOW NORMAL FOR
THIS TIME OF YEAR. HOOLEY
&&
.AVIATION...
SKIES WILL BE PARTLY TO MOSTLY CLOUDY THIS EVENING THROUGH
TONIGHT. A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATE THIS
AFTERNOON FROM KBIL WESTWARD AND ACROSS THE EASTERN AREAS LATE
TONIGHT. EXPECT INCREASING CLOUDS AND A CHANCE FOR THUNDERSTORMS
FROM KBIL WESTWARD LATE THIS AFTERNOON INTO THE EVENING. THE
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE STRONG GUSTY
WINDS TO AROUND 50 MPH. EXPECT A SLIGHT THUNDERSTORM CHANCE EAST
OF KBIL LATE THIS EVENING THROUGH THE OVERNIGHT HOURS. MVFR
CONDITIONS WILL BE POSSIBLE IN AND NEAR THUNDERSTORM ACTIVITY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL. THE MOUNTAINS WILL BE
OBSCURED AT TIMES. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 061/081 059/080 058/085 059/086 061/084 060/084 061/084
33/T 53/T 32/T 33/T 32/T 33/T 32/T
LVM 053/084 051/079 049/085 051/085 052/081 051/080 051/080
44/T 53/T 23/T 33/T 33/T 33/T 32/T
HDN 060/085 059/082 058/086 059/086 060/085 060/085 060/085
35/T 64/T 32/T 33/T 32/T 33/T 32/T
MLS 062/085 060/082 060/085 060/086 062/085 062/082 063/085
25/T 74/T 33/T 33/T 34/T 33/T 33/T
4BQ 057/084 056/082 058/083 058/085 058/085 059/083 060/084
24/T 54/T 33/T 33/T 34/T 33/T 33/T
BHK 052/079 056/078 056/079 056/081 058/080 057/080 058/080
23/T 54/T 33/T 32/T 34/T 33/T 34/T
SHR 056/084 055/081 055/086 055/085 056/083 055/083 056/083
35/T 64/T 32/T 33/T 32/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 28-40-41-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
347 PM CDT SAT JUL 27 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY AFTERNOON.
ISSUED AT 345 PM CDT SAT JUL 27 2013
FORECAST CONCERNS IN THE SHORT TERM INCLUDE TEMPS WELL BELOW
NORMAL FOR THIS TIME OF YEAR ALONG WITH SMALL PRECIP CHANCES.
CURRENT UPPER AIR...WIND PROFILER NETWORK AND WATER VAPOR SATELLITE
IMAGERY SHOWING AN UPPER LOW OVER THE GREAT LAKES THAT IS EXPECTED
TO WOBBLE IN PLACE THE NEXT 24 HOURS. ANOTHER LOW PRESSURE REGION
WAS OVER EASTERN BRITISH COLUMBIA MOVING INTO ALBERTA...WHILE
FURTHER SOUTH ANOTHER LOW PRESSURE CIRCULATION COULD BE SEEN A
COUPLE HUNDRED MILES OFF THE CENTRAL CALIFORNIA COAST. A WEAK RIDGE
OF HIGH PRESSURE WAS SITUATED OVER THE ROCKIES WITH VARIOUS MINOR
SHORT WAVES ROTATING THROUGH THIS RIDGE...INCLUDING ONE THAT
TRIGGERED ISOLATED TSTMS THIS MORNING. AT THE SURFACE A RIDGE OF
HIGH PRESSURE EXTENDS FROM THE NORTHERN INTO THE CENTRAL PLAINS. LOW
PRESSURE AND AN ASSOCIATED BOUNDARY WAS NOTED OVER THE LEE OF THE
ROCKIES AND THEN EAST ACROSS SOUTHERN OKLAHOMA AND ARKANSAS. CLOSER
TO HOME...WINDS ARE LIGHT DUE TO THE WEAK PRESSURE GRADIENT.
DEWPOINTS WERE VERY COMFORTABLE FOR THIS TIME OF YEAR RANGING FROM
THE MID 40S ACROSS THE NORTHERN CWA TO THE LOWER/MID 50S SOUTH.
FOR TONIGHT...IT APPEARS THE BEST CHANCE FOR RAIN WILL HINGE ON THE
DEGREE OF WARM ADVECTION THAT SETS UP. BOTH THE NAM AND RAP MODELS
ARE IN AGREEMENT IN DEVELOPING A DECENT LOW LEVEL JET AFTER 02Z IN
THE SOUTHERN PART OF THE CWA. THE 310K DEGREE ISENTROPIC PLAN VIEW
PLOT SHOWS THIS NICELY WITH A 30-40 KT JET RIDING OVER THE SURFACE
BOUNDARY AND INTO OUR AREA. MIXING RATIOS HERE ARE AROUND 9-10 G/KG
WITH BEST LIFT IN THE SOUTHWEST. REAL QUESTION THEN BECOME HOW FAR
INTO THE CWA TO EXTEND THE RAIN CHANCES AS WARM ADVECTION NIL OVER
THE NORTHEAST THIRD OF THE CWA ACCORDING TO THE NAM. ANY TSTM
ACTIVITY THAT DOES POP UP OVERNIGHT SHOULD REMAIN BELOW SEVERE
LIMITS AS MU CAPE ONLY A COUPLE HUNDRED J/KG AT BEST EVEN THOUGH
DEEP LAYER SHEAR IS RESPECTABLE. DEWPOINTS TO REMAIN LOW AND GIVEN
THE COOLER AIR MASS...OVERNIGHT LOWS SHOULD BE AROUND 15 DEGREES
BELOW AVERAGE FOR THIS TIME OF YEAR WHICH IS 65 IN KGRI.
PRECIPITATION CHANCES TO CONTINUE DURING THE DAYTIME ON SUNDAY AS
MODELS IN GOOD AGREEMENT IN SLIDING SHORT WAVE TROUGH FROM THE
DESERT SW INTO OUR NECK OF THE WOODS. BEST CHANCES STILL APPEAR TO
BE IN OUR SOUTHERN CWA...ACTUALLY SOUTH OF THERE...CLOSER TO THE
FRONT. ONCE AGAIN...MU CAPE VALUES REMAIN LOW DUE TO THE COOLER LOW
LEVEL TEMPERATURES AND LOWER DEW POINTS...SO SEVERE CHANCES ARE
MINIMAL. HIGHS ON SUNDAY ARE EXPECTED TO REMAIN BELOW NORMAL WITH
COOLER AIR MASS. KGRI AVERAGE HIGH IS 87 AND FORECAST HIGH WILL BE
ABOUT 15 DEGREES BELOW THAT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 340 PM CDT SAT JUL 27 2013 MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS AND TEMPERATURES.
GENERALLY NORTHWEST FLOW WILL CONTINUE THROUGH THE PERIOD. THERE ARE
SEVERAL UPPER LEVEL WAVES THAT MOVE THROUGH THE AREA AND BRING
CHANCES FOR PRECIPITATION TO THE AREA. IT CERTAINLY WILL NOT RAIN
ALL THE TIME OR IN ALL LOCATIONS.
THE STRONGEST OF THE UPPER LEVEL WAVES WILL BE MOVING THROUGH THE
AREA SUNDAY NIGHT AND MONDAY. THIS WILL BE THE BEST CHANCE FOR
PRECIPITATION. SUNDAY NIGHT THE UPPER WAVE WILL CONTINUE TO PUSH
THROUGH THE AREA. PRECIPITATION SPREADS A LITTLE TO THE NORTH DURING
THE NIGHT. THIS WILL BE THE BEST CHANCE FOR PRECIPITATION ESPECIALLY
IN THE SOUTH. THE UPPER WAVE WILL START TO MOVE OUT OF THE AREA ON
MONDAY BUT THERE STILL REMAINS A CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS ACROSS THE AREA DURING THE DAY. THE BEST CHANCE WILL
BE IN THE SOUTHEAST PART OF THE AREA.
MONDAY NIGHT BRINGS THE FIRST BREAK...BUT ONLY FOR PART OF THE
FORECAST AREA. A SURFACE HIGH TRIES TO BUILD INTO THE AREA BUT CAN
ONLY BRING A BREAK TO PART OF THE AREA WITH ISOLATED PRECIPITATION
IN THE SOUTHEAST.
FOR THE PERIOD TUESDAY THROUGH WEDNESDAY NIGHT. A SERIES OF WEAK
UPPER LEVEL WAVES WILL MOVE THROUGH THE AREA. THERE ARE CHANCES FOR
THUNDERSTORMS FOR PORTIONS OF THE AREA MAINLY IN THE WEST AND NORTH.
THE CHANCES ARE FAIRLY SMALL AND MODELS HAVE SLIGHTLY DIFFERENT
TIMING OF THE WAVES AS THEY MOVE THROUGH THE AREA.
THURSDAY THROUGH FRIDAY NIGHT THE CHANCES FOR THUNDERSTORMS WILL BE
ACROSS THE ENTIRE AREA. THESE TOO ARE FAIRLY SMALL CHANCES AND IT IS
POSSIBLE THAT THERE MAY NOT BE PRECIPITATION AT SOME LOCATIONS.
A SURFACE HIGH PRESSURE SYSTEM TRIES TO SETTLE INTO THE FORECAST
AREA AGAIN ON SATURDAY AND MOST OF THE AREA WILL BE DRY. THERE IS A
SLIGHT CHANCE IN THE FAR SOUTH.
TEMPERATURES WILL REMAIN ON THE COOL SIDE FOR MONDAY...BUT RETURN TO
MORE SEASONABLE TEMPERATURES FOR THE REST OF THE WEEK WHEN
TEMPERATURES ARE EXPECTED TO BE AT OR A LITTLE BELOW NORMAL FOR THIS
TIME OF YEAR.
&&
.AVIATION...FOR THE 18Z TAF THROUGH 18Z SUNDAY AFTERNOON...ISSUED
AT 1220 PM CDT SAT JUL 27 2013
EXPECT VFR CONDITIONS THROUGH THE FORECAST PERIOD. WITH WEAK HIGH
PRESSURE NOTED OVER THE AREA...EXPECT WINDS TO REMAIN LIGHT THIS
AFTERNOON AND OVERNIGHT BEFORE PICKING UP JUST A LITTLE AND
BECOMING ESE SUNDAY AFTER SUNRISE. SHOWERS HAVE WEAKENED DURING
THE MORNING AND SHOULD BE DRY THE REST OF THE DAY. JUST AN OUTSIDE
CHANCE FOR SOME THUNDERSTORMS OVERNIGHT BUT BETTER CHANCES WELL
SOUTH OF THE TERMINAL AND WILL LEAVE OUT MENTION IN TAF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...EWALD
LONG TERM...JCB
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1242 PM CDT SAT JUL 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
TODAY...PER UNR UA SOUNDING AND THE RAP AND NAM MODELS...IT LOOKS
LIKE THERE IS A MOIST AND MODESTLY UNSTABLE EML OPERATING ACROSS THE
FCST AREA. THE NAM...RAP...HRRR AND GEMREG MODELS SEEM TO HAVE A
HANDLE ON THIS DISTURBANCE WITH DIFFERENCES IN THE LOCATION OF THE
RAINFALL. THE CONSENSUS IS FOR THE STORMS ACROSS WRN AND SWRN NEB TO
DECAY OR MOVE OUT OF THE FCST AREA EARLY THIS MORNING WHILE THE
SECOND BAND ACROSS NCNTL NEB CONTINUES TO OPERATE THROUGHOUT THE
MORNING AND THEN DECAYS DURING THE AFTERNOON.
SPC PUBLISHED THIS DISCUSSION AT 742Z...MODERATE MIDLEVEL WAA AND
FRONTOGENESIS IS LOCATED OVER WRN/CNTRL NEB THIS MORNING. IN
ADDITION...A PLUME OF MOISTURE AT 600-700 MB AND STEEP MIDLEVEL
LAPSE RATES IS YIELDING MODERATE MUCAPE VALUES UPWARDS OF 1000 J/KG.
THIS BUOYANCY COMBINED WITH THE ZONE OF FOCUSED MESOSCALE ASCENT IS
RESULTING IN SCATTERED THUNDERSTORM DEVELOPMENT OVER THE AREA. IN
ADDITION...A 60 KT MIDLEVEL NNWLY JET IS CONTRIBUTING TO STRONG
EFFECTIVE BULK SHEAR ON THE ORDER OF 40-60 KT...WHICH IS SUPPORTIVE
OF ELEVATED SUPERCELL DEVELOPMENT. THIS ENVIRONMENT MAY RESULT IN
ISOLATED INSTANCES OF LARGE HAIL DURING THE MORNING...BUT THE THREAT
IS TOO MARGINAL FOR A WW.
TONIGHT...SOME MODEL SOLNS...THE NAM IN PARTICULAR...SUGGEST ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SWRN
NEB. THE GEMREG IS FARTHER SOUTH HOLDS THE QPF ACROSS KS.
THIS WEATHER SHOULD BE GENERATED BY A DISTURBANCE...CURRENTLY ACROSS
WRN MT...WHICH WILL DROP SOUTH THROUGH THE NW FLOW AND MAINLY AFFECT
THE CNTL HIGH PLAINS BUT THE NAM SHOWS A BURST OF CONVECTION FIRING
ACROSS SWRN NEB. GIVEN THE NORTHWEST FLOW UNDERWAY AND THE APPARENT
FERTILE ENVIRONMENT FOR RAINFALL...THE NAM IS A CREDIBLE SOLN. SO
TSTMS ARE POSSIBLE TONIGHT...MAINLY SOUTH OF INTERSTATE 80.
HIGH TEMPS TODAY SHOULD REMAIN IN THE 70S WITH THE COOL SPOT ACROSS
CUSTER COUNTY...NEAR 70 FOR A HIGH THERE. LOWS TONIGHT IN THE 40S
AND 50S LOOK REASONABLE GIVEN THE COOL HIGH ACROSS SRN MANITOBA AND
BACKED SFC WINDS TUGGING ON THE COOL AIR FROM THE NORTH.
.LONG TERM...
.SUNDAY THROUGH MONDAY...
A FAIRLY COOL PERIOD STARTS THE WEEK AS MODELS ARE IN GOOD AGREEMENT
FOR A SLOW TRANSITION TO A FAIRLY ACTIVE AND WET START OF THE
WEEK. SEVERAL BOUNDARIES WILL COME INTO PLAY AS MOISTURE POOLS
ACROSS THE WEST IN A PREVAILING UPSLOPE PATTERN. A FRONTAL
BOUNDARY WILL EXTEND SOUTH ON THE HIGH PLAINS...WHILE SURFACE
RIDGING REACHES FROM THE NORTHERN MIDWEST THROUGH THE OHIO VALLEY.
AT THIS TIME MONDAY EVENING APPEARS A GOOD SHOT FOR SEVERE
THUNDERSTORM DEVELOPMENT AS THE UPPER RIDGE AXIS WEAKENS AND
EMBEDDED WAVES MOVE EAST IN THE EVENING. IF ALL PANS OUT GOOD
INSTABILITY EXTENDS THROUGH THE FAR NORTHWEST SANDHILLS THAT WOULD
PROVIDE THE ENVIRONMENT FOR SEVERE STORMS MONDAY NIGHT. CONSIDERABLE
CLOUD COVERAGE WILL HELP KEEP TEMPERATURES DOWN AS WELL WITH HIGHS
MAINLY IN 70S... COMPARED TO NORMALS THAT WOULD BE CLOSER TO THE
UPPER 80S.
.TUESDAY THROUGH SATURDAY...
THE PATTERN REMAINS OVERALL PROGRESSIVE WITH SURFACE BOUNDARIES IN
PLACE FOR A CONTINUED CHANCE FOR DAILY THUNDERSTORM ACTIVITY. AS THE
FLOW BECOMES MORE ZONAL TEMPERATURES WILL TREND TOWARD NORMAL BY MIDWEEK.
THE EMBEDDED WAVES CREATE CHALLENGES AS TO THE AREAL COVERAGE OF
STORMS. THE UPPER RIDGE STRENGTHENS ACROSS THE INTERMOUNTAIN
REGION THROUGH MIDWEEK THEN WEAKENS AS THE NEXT UPPER LOW MOVES
INTO THE NORTHEAST PACIFIC. THE RISING HEIGHTS MIDWEEK WILL HELP
SHIFT THE BETTER CHANCE FOR RAIN NORTH UNTIL THE APPROACH OF THE
WEEKEND. TEMPERATURES REBOUND IN THE FAR WEST TUESDAY...ALTHOUGH
IF MODELS SLOW DOWN TEMPERATURES MAY STRUGGLE TO REACH THE 80S.
FOR NOW TRENDED TEMPERATURES UP BEYOND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1242 PM CDT SAT JUL 27 2013
MOSTLY VFR CONDITIONS ARE ANTICIPATED AT KLBF AND KVTN THROUGH 06Z
TONIGHT...HOWEVER ISOLATED LIGHT RAIN SHOWERS CONTINUE EARLY THIS
AFTERNOON ACROSS WESTERN AND SOUTHWEST NEBRASKA...THERE IS A
SLIGHT POSSIBILITY THAT A STRAY SHOWER OR TWO WOULD DRIFT OVER A
TERMINAL AND BRIEFLY REDUCE VISIBILITY TO MVFR. WHILE NOT
ANTICIPATED AT THIS TIME...WILL CONTINUE TO MONITOR. BEYOND 06Z
TONIGHT...ADDITIONAL SHOWERS...POSSIBLY MORE WIDESPREAD...ARE
EXPECTED TO DEVELOP ACROSS SOUTHWEST NEBRASKA AND PORTIONS OF THE
SOUTHERN SANDHILLS. WHILE GUIDANCE IS SOMEWHAT SPLIT WITH TIMING
AND THE LOCATION OF THE QPF...WILL GO AHEAD AND INTRODUCE A PROB30
FOR -SHRA AT KLBF FROM 09-12Z. THERES MUCH LESS CONFIDENCE OF
SEEING STORMS OVERNIGHT AT KVTN...SO WILL NOT INCLUDE ANY MENTION
AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...KECK
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 PM EDT SAT JUL 27 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE CAROLINAS FROM THE WEST
TONIGHT...THEN STALL OUT OVER THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM SATURDAY...
CONVERGENT FEATURES ABOUND THIS AFTERNOON. A MOISTURE PLUME AND
SHORT WAVE LIFTING AROUND THE UPPER TROF INITIATED WIDESPREAD RAIN
IN UPSLOPE FLOW ALONG WITH STRONGER CONVECTION IN THE FOOTHILLS
DURING THE MORNING. THESE FEATURES MOVED EAST AND INTO STRONGER
INSTABILITY IN THE PIEDMONT WHERE INSOLATION HAD ALLOWED A
DIFFERENTIAL HEATING BOUNDARY TO SET UP. THE RESULTING AREA OF
SHOWERS AND STORMS WILL CONTINUE TO MOVE EAST AS WE PROGRESS INTO
THE AFTERNOON AND HAVE RAISED POPS ACROSS CENTRAL NC THROUGH THE
EVENING. THE RELATIVELY ORGANIZED LINE OF HEAVIER SHOWERS/STORMS IS
CAPABLE OF PRODUCING RAINFALL RATES OF 2 INCHES PER HOUR...WHICH
COULD PRODUCE MINOR FLOODING IN URBAN AREAS.
RAP AND THE HRRR IN CONJUCTION DEPICT A VORT MAX LIFTING NORTHEAST
OUT OF SOUTH CAROLINA AND ACROSS THE AREA EARLY TONIGHT...PROVIDING
FURTHER SUPPORT FOR CONVECTION ACROSS THE CENTRAL CWFA...
FAY-TRIANGLE AREA...FOR A FEW HOURS AFTER SUNSET. OTHERWISE...
CONVECTION WILL BE WANING TO CHANCE POPS AFTER MIDNIGHT.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 245 PM SATURDAY...
COLD FRONT WILL BE MOVING ACROSS THE MOUNTAINS EARLY SUNDAY...
MEANWHILE THE UPPER LOW OVER THE GREAT LAKES LIFTS NORTHEAST WITH A
PERSISTENT TROF STRETCHING DOWN THE EAST COAST. IN THE WEST...
MORNING CLOUDINESS WILL INTIALLY HINDER DESTABILIZATION...BUT
MODERATE INSTABILITY WILL DEVELOP WITH THE ARRIVAL OF MID LEVEL
DRIER AIR...PROMOTING A BETTER CHANCE OF DOWNBURST WINDS WITH DCAPE
ON THE ORDER OF 1000J. MEANWHILE...ENTRANCE OF DEPARTING UPPER JET
WILL ALIGN WITH THE BETTER LOW LEVEL CONVERGENCE EAST OF THE SURFACE
FRONT...WHERE PRECIPITABLE WATERS REMAIN >1.75 INCHES WITH MUCAPE
>1200J. AS SUCH...WILL HAVE CHANCE POPS THROUGH THE DAY...SHADED
HIGHER TOWARDS THE EAST. POPS WILL TAPER OFF FROM THE WEST SUNDAY
NIGHT. HIGH TEMPS WILL RANGE FROM THE LOW 80S WEST...WHICH COULD BE
A SHADE WARM IF LOW CLOUDINESS PERSISTS THROUGHOUT THE MORNING...TO
UPPER 80S IN THE EAST. MINS SUNDAY NIGHT WILL BE IN THE 65 TO 70
RANGE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 245 PM SATURDAY...
THE LONG TERM PERIOD WILL START WITH A COLD FRONT MOVING SLOWLY
ACROSS THE REGION...ALTHOUGH EXACTLY WHERE IT ENDS UP IS STILL IN
QUESTION. IT APPEARS THAT THE FRONT WILL LIKELY STALL/WASH OUT
SOMEWHERE ACROSS EASTERN/SOUTHERN NC. THEREFORE...RESIDUAL
MOISTURE/LIFT ASSOCIATED WITH THE FRONT SHOULD BE ENOUGH TO SUPPORT
SLIGHT CHANCE POPS ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA
ON MONDAY. AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST...ENOUGH
DRYING SHOULD OCCUR FURTHER NORTH AND WEST TO PRECLUDE ANY PRECIP.
THEN MODELS INDICATE THAT THE BEST MOISTURE WILL REMAIN SHUNTED TO
OUR SOUTH AND EAST ON TUESDAY AND THEREFORE AM EXPECTING A MOSTLY
DRY DAY ACROSS THE REGION. THE EXCEPTIONS MAY BE ACROSS THE EXTREME
SOUTH AND EAST (DUE TO THE PROXIMITY OF THE RESIDUAL BOUNDARY AND/OR
MOISTURE) AND THEN BY LATE TUESDAY/TUESDAY NIGHT ACROSS THE WEST AS
MOISTURE BEGINS TO RETURN HERE.
THROUGH THE REMAINDER OF THE EXTENDED PERIOD...THE OVERALL PATTERN
WILL REMAIN FAIRLY PROGRESSIVE AS OUR NEXT UPPER TROUGH/SURFACE COLD
FRONT IS PROGGED TO APPROACH/CROSS THE REGION WEDNESDAY INTO
THURSDAY. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS...WITH THE BEST CHANCE OF RAIN CURRENTLY LOOKING TO
OCCUR LATE WEDNESDAY INTO THURSDAY. THEN...IT APPEARS THE FRONT WILL
SHIFT EAST OF THE AREA BY FRIDAY MORNING...BUT SIMILAR TO THE PAST
COUPLE OF FRONTS THAT HAVE/WILL IMPACT THE AREA...IT MAY STALL
ACROSS THE EASTERN/SOUTHERN PORTIONS OF THE STATE. THIS WOULD RESULT
IN A SOME PRECIP ACTIVITY...AT LEAST ACROSS THE PORTION OF THE
FORECAST AREA. HOWEVER...IT APPEARS FRIDAY AND SATURDAY SHOULD BE
RELATIVELY DRY AS HIGH PRESSURE BUILDS INTO THE AREA. THEN YET
ANOTHER SYSTEM IS PROGGED TO APPROACH THE AREA LATE IN THE WEEKEND
(MAYBE AS EARLY AS SATURDAY NIGHT).
TEMPS WILL 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 /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
24-HR TAF PERIOD:
MVFR CEILINGS AND VISIBILITY WILL BE ASSOCIATED WITH ONGOING
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORM THIS AFTERNOON OVER
THE WESTERN PIEDMONT. CONDITIONS WILL GRADUALLY SHIFT EAST AS THE
AFTERNOON PROGRESSES...WITH THUNDERSTORMS AT GSO/INT THROUGH
20Z...AND THE VICINITY OF RDU/FAY BY 21Z. STRONGER CONVECTION WILL
DIMINISH WITH LOSS OF HEATING...BUT SCATTERED SHOWERS/ISOLATED
THUNDER WILL PERSIST IN THE EAST THROUGH MIDNIGHT. IFR FOG/STRATUS
ARE EXPECTED AT GSO/INT AFTER MIDNIGHT. MVFR FOG MAY BE EXPECTED IN
THE EASTERN TAF SITES...BUT BOTH CEILING AND VISILITY COULD BE IFR
IF THESE SITES RECEIVE SOME SUBSTANTIAL RAIN THIS EVENING/EARLY
TONIGHT. CONDITIONS WILL IMPROVE TO MVFR/VFR WITH HEATING BETWEEN
12-14Z TOMORROW MORNING.
LOOKING AHEAD:
EXPECT SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS AGAIN SUNDAY
AFTERNOON/EVENING WITH FOG/STRATUS SUNDAY NIGHT...IN ADVANCE OF A
WEAK FRONT APPROACHING THE REGION FROM THE W/NW. DRIER CONDITIONS
SHOULD PREVAIL EARLY NEXT WEEK...THOUGH THE FRONT MAY STILL OVER OR
JUST SOUTH OF CENTRAL NC AND A POTENTIAL FOR MORNING FOG/STRATUS AND
AFTERNOON CONVECTION MAY PERSIST...ESPECIALLY AT KFAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MLM
NEAR TERM...MLM
SHORT TERM...MLM
LONG TERM...KRR
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1240 PM CDT SAT JUL 27 2013
.UPDATE...
ISSUED AT 1240 PM CDT SAT JUL 27 2013
FAIR WEATHER CUMULUS FIELD HAS APPEARED FASTER AND A BIT MORE
ROBUST THAN ORIGINALLY FORECAST. HAVE UPPED THE SKY COVER WHICH
MAY ULTIMATELY EFFECT MAX TEMPS...BUT CURRENT FORECAST LOOKS
GOOD. LEFT ANY MENTION OF POPS OUT DESPITE -RASH GETTING CLOSE TO
EASTERN CWFA. 88D ECHOS SHRINKING AND UPSTREAM METARS/RADAR
SHOWING LITTLE WESTWARD PROGRESS ATTM. WILL NEED TO WATCH IT FOR
EVENING THOUGH AS IR SHOWS COOLING TOPS AND HRRR DOES BRUSH LOW
TO WADENA COUNTIES WITH A FEW -RASH AROUND 00Z.
UPDATE ISSUED AT 946 AM CDT SAT JUL 27 2013
MINOR ADJUSTMENTS WERE MADE TO THE TRENDS IN SKY AND TEMPERATURE
TO MATCH REALITY. OTHERWISE CURRENT FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 650 AM CDT SAT JUL 27 2013
NO CHANGES MADE THIS UPDATE PERIOD.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT SAT JUL 27 2013
FORECAST CHALLENGE CONCERNS TEMPERATURES AND EARLY NEXT WEEK PCPN
CHANCES. MODEL DIFFERENCES MAINLY WITH TIMING OF FRONTAL BOUNDARY
MONDAY. WILL USE MODEL BLEND.
SURFACE HIGH PRESSURE TO DRIFT SLOWLY EAST ACROSS FA THIS WEEKEND.
CURRENT TEMPERATURES SHOWING BEST POTENTIAL FOR RECORD LOWS ACROSS
NORTHERN FA WHERE TEMPERATURES CURRENTLY IN THE MID 40S. THERMAL
COLUMN WARMS SLIGHTLY TODAY AND CLOUD COVER NOT TO BE QUITE AS
EXTENSIVE AS YESTERDAY. WITH COOL START HOWEVER MAXIMUM
TEMPERATURES LIKELY ONLY TO BE A FEW DEGREES WARMER THAN
YESTERDAY.
WITH SURFACE HIGH OVERHEAD...SKC AND LIGHT WINDS TONIGHT WILL AGAIN
NEED TO MONITOR FOR RECORD LOW TEMPERATURES.
COLUMN CONTINUES TO SLOWLY MODERATE SUNDAY SO WILL SEE SLIGHTLY
WARMER TEMPERATURES BUT STILL WAY BLO AVERAGE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT JUL 27 2013
AS HIGH PRESSURE SHIFTS EAST SUNDAY NIGHT WEAK RETURN FLOW AND
WARM ADVECTION SHOULD END THE THREAT OF RECORD LOW TEMPERATURES.
MODELS SHOWING SLIGHT DIFFERENCES IN TIMING OF NEXT COLD FRONT
MONDAY WITH THE NAM THE QUICKEST. MODELS ALSO DIFFER ON RAIN
POTENTIAL IN WARM ADVECTION REGIME AHEAD OF BOUNDARY PASSAGE. FOR
THIS ONLY MADE MINOR ADJUSTMENTS TO POPS. DEPENDING ON CLOUD COVER
TEMPERATURES WILL BE WARMER BUT STILL BLO AVERAGE.
TUESDAY-FRIDAY...BOTH THE 00Z GFS/ECMWF ARE IN AGREEMENT BRINGING
THE WEAK SFC FRONT THROUGH ON TUESDAY...WITH SCATTERED CONVECTION
ALONG AND AHEAD OF IT.
CONFLUENT NORTHWEST FLOW ALOFT IS EXPECTED TO SET UP ACROSS THE
NORTHERN PLAINS FOR THE MIDDLE OF THE WEEK....DOWNSTREAM FROM THE
EASTERN PACIFIC/WESTERN NORTH AMERICA BLOCKING PATTERN. THIS IS
EXPECTED TO LEAD TO A RELATIVELY QUIET PERIOD OF WEATHER
MID-WEEK...WITH WEAK SFC HIGH PRESSURE IN PLACE.
HAVE INCLUDED LOW POPS THUR NIGHT/FRI AS ENERGY FROM THE WESTERN US
UPPER LOW SHIFTS EAST WITH INCREASING ZONAL FLOW INTO THE CENTRAL
PLAINS. HOWEVER...MODELS INDICATE DRY NORTHERLY LOW-LEVEL FLOW
PERSISTING OVER THE AREA. THUS...FORECAST CONFIDENCE IS LOW BY LATE
WEEK.
TEMPERATURES THROUGH THE PERIOD WILL REMAIN NEAR TO A BIT BELOW
NORMAL...WITH HIGHS MAINLY IN THE 70S AND LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT JUL 27 2013
VFR TODAY WITH SCT/BKN DECK AOA 5KFT. GUSTS 20 TO 25KTS POSSIBLE IN
THE VALLEY AND AT BJI THRU THE AFTERNOON. SKC DEVELOPING THIS
EVENING AND OVERNIGHT WITH LIGHT AND VARIABLE WINDS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...KAISER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
324 PM EDT SAT JUL 27 2013
.SYNOPSIS...
COLD FRONT TONIGHT. HIGH PRESSURE BUILDS BACK SUNDAY INTO MONDAY.
DISTURBANCE LATE TUESDAY...WITH PEAK SUPPORT TO OUR SOUTH.
&&
.NEAR TERM /THROUGH SUNDAY/...
SOME CLEARING AND HEATING OVER THE WEST VIRGINIA LOWLANDS
REALIZING SOME CAPE WITH SOME TALLER CELLS AND A LITTLE BIT OF
LIGHTNING NOW TO BE FOUND IN THE CONVECTION IN THIS AREA. VORT MAX
HAS BEEN A BIT LESS EFFECTIVE THAN EXPECTED IN TERMS OF COVERAGE
OF SHOWERS OVER THE TRI STATE AREA INTO SOUTHEAST OHIO...AND
TRENDED THESE POPS DOWNWARD THROUGH THE REMAINDER OF THE AFTERNOON
BEFORE BRINGING THEM BACK TO LIKELY WITH THE COLD FRONT. FEEL THE
BEST GUIDANCE OUT THERE RIGHT NOW IS THE HRRR AND THE LOCAL WRF
MODELS...AND LEAN ON THESE THROUGH TE 12Z TIME FRAME. REMOVE
THUNDER CHANCES LATE THIS EVENING...BUT THAT TIMING THAT LATE MAY
STILL BE TOO GENEROUS IN THAT SENSE.
POST FRONTAL ENVIRONMENT WILL NOT CLEAR OUT QUICKLY. HIDDEN IN THE
LOW LEVELS WILL BE A BAND OF MOISTURE AND A RESULTANT LOW LEVEL
STRATUS DECK. THIS SHOULD ERODE WEST TO EAST THROUGH THE LOWLANDS
BY EVENING...BUT LINGER IN THE MOUNTAINS BEYOND 00Z MONDAY.
CLOUDS WILL KEEP THE TEMPERATURES IN THE 60S IN THE NORTHEAST
MOUNTAINS SUNDAY...AND MID 70S FOR THE MOST PART OVER THE
LOWLANDS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
UPPER LOW OVER THE GREAT LAKES WILL SLOWLY LIFT OUT BY
TUESDAY...WITH NORTHWEST FLOW ALOFT BACKING TO A MORE WESTERLY
DIRECTION. THIS WILL ALLOW A SIGNIFICANT SHORT WAVE AND SURFACE LOW
TO TRACK EASTWARD ALONG THE SOUTHERN EDGE OF THE WESTERLIES INTO THE
MID AND LOWER MISSISSIPPI VALLEY TUESDAY. ALL THE MODELS LATCH ONTO
THIS SYSTEM...BUT THERE ARE DIFFERENCES IN THE EXACT TRACK...
TIMING...AND QPF. THIS IS DUE TO HOW MUCH THE FLOW ACTUALLY BACKS
AHEAD OF THE APPROACHING SYSTEM. THERE IS REALLY NO MODEL CONSENSUS
TO EXUDE HIGH CONFIDENCE...SO WILL BASICALLY GO WITH PERSISTENCE ON
OUR FORECAST...AND FOCUS HIGHEST POPS AND QPF ACROSS THE SOUTH HALF
OF THE AREA...WITH THE LEADING EDGE OF THE PRECIP SHIELD TO ARRIVE
AS SOON AS LATER TUESDAY NIGHT. UNTIL THEN...DRY HIGH PRESSURE WITH
MODERATE TEMPERATURES AND HUMIDITY WILL MAKE MONDAY...AND EVEN INTO
TUESDAY... A RATHER TRANQUIL AND UNOPPRESSIVE PERIOD WITH
TEMPERATURES NEAR NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
SHORT WAVE AND LOW PRESSURE WILL CONTINUE MOVING EASTWARD MID WEEK
ACROSS THE OHIO AND TENNESSEE VALLEYS...WITH THE HIGHEST POPS AND
QPF WEDNESDAY AND WEDNESDAY NIGHT. AGAIN...WILL FOCUS ON A MORE
SOUTHERN IMPACT GIVEN UNCERTAINTY IN THE EXACT TRACK AND WITH ANY
ONGOING CONVECTIVE COMPLEXES TENDING TO SINK SOUTH AND EAST. WILL
LINGER POPS INTO THURSDAY MAINLY IN THE MOUNTAINS...BUT HIGH
PRESSURE WILL BUILD IN BY LATER THURSDAY WITH DRIER
WEATHER...MODERATE TEMPERATURES AND HUMIDITIES RETURNING THROUGH
FRIDAY. SATURDAY WILL LIKELY SEE ANOTHER SYSTEM APPROACHING FOR A
POSSIBLE WET WEEKEND. AGAIN...TEMPERATURES ARE EXPECTED TO BE NEAR
NORMAL.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
NUMEROUS SHOWERS WITH A FEW THUNDERSTORMS POSSIBLE AHEAD OF A
STRONG COLD FRONT TODAY. CHANCES FOR SHOWERS CONTINUE INTO TONIGHT
WITH THE COD FRONT ITSELF.
THROUGH THE REMAINDER OF TODAY...SOME CLEARING OVER THE WESTERN
LOWLANDS HAS ALLOWED THE CAPE TO SPIKE...AND NOW ARE SEEING A
COUPLE LIGHTNING STRIKES IN THE NORTH CENTRAL PART OF WEST
VIRGINIA. NO PREVAILING TSRA FOR THE TERMINALS...JUST USING
VCTS/CB THROUGH EVENING.
CARRYING A TEMPO IFR OFF THE BAT FOR EKN IN STEADIER RAIN WITH
PREVAILING MVFR VISIBILITIES.
EXPECTING A LOW STRATUS DECK TO MATERIALIZE BEHIND THE FRONT
SUNDAY...WITH MVFR CEILINGS POSSIBLE BENEATH THE ELEVATED
INVERSION LAYER. STILL MAY HAVE TO DODGE A SHOWER OR TWO SOUTHEAST
OF THE OHIO RIVER EARLY SUNDAY. LOW STRATUS DECK ERODES AFTER 18Z
FOR THE LOWLANDS...BUT COULD LINGER IN THE MOUNTAINS INTO SUNDAY
EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MAY NEED A FEW MORE TEMPO AMENDMENTS IN
SHRA/TSRA TODAY. TIMING OF COLD FRONT AND ENDING SHOWERS 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 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY H H M H H H H H H H H H
EKN CONSISTENCY H H M M M M H H H H H M
PKB CONSISTENCY H M M H H M M M M H H H
CKB CONSISTENCY H H H M M M H H H H H H
AFTER 18Z SUNDAY...
IFR IN VALLEY FOG MONDAY AND TUESDAY MORNINGS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
230 PM EDT SAT JUL 27 2013
.SYNOPSIS...
COLD FRONT TONIGHT. HIGH PRESSURE BUILDS BACK SUNDAY INTO MONDAY.
DISTURBANCE LATE TUESDAY...WITH PEAK SUPPORT TO OUR SOUTH.
&&
.NEAR TERM /THROUGH SUNDAY/...
SOME CLEARING AND HEATING OVER THE WEST VIRGINIA LOWLANDS
REALIZING SOME CAPE WITH SOME TALLER CELLS AND A LITTLE BIT OF
LIGHTNING NOW TO BE FOUND IN THE CONVECTION IN THIS AREA. VORT MAX
HAS BEEN A BIT LESS EFFECTIVE THAN EXPECTED IN TERMS OF COVERAGE
OF SHOWERS OVER THE TRI STATE AREA INTO SOUTHEAST OHIO...AND
TRENDED THESE POPS DOWNWARD THROUGH THE REMAINDER OF THE AFTERNOON
BEFORE BRINGING THEM BACK TO LIKELY WITH THE COLD FRONT. FEEL THE
BEST GUIDANCE OUT THERE RIGHT NOW IS THE HRRR AND THE LOCAL WRF
MODELS...AND LEAN ON THESE THROUGH TE 12Z TIME FRAME. REMOVE
THUNDER CHANCES LATE THIS EVENING...BUT THAT TIMING THAT LATE MAY
STILL BE TOO GENEROUS IN THAT SENSE.
POST FRONTAL ENVIRONMENT WILL NOT CLEAR OUT QUICKLY. HIDDEN IN THE
LOW LEVELS WILL BE A BAND OF MOISTURE AND A RESULTANT LOW LEVEL
STRATUS DECK. THIS SHOULD ERODE WEST TO EAST THROUGH THE LOWLANDS
BY EVENING...BUT LINGER IN THE MOUNTAINS BEYOND 00Z MONDAY.
CLOUDS WILL KEEP THE TEMPERATURES IN THE 60S IN THE NORTHEAST
MOUNTAINS SUNDAY...AND MID 70S FOR THE MOST PART OVER THE
LOWLANDS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
OVERALL QUIETER AND COOLER WEATHER IN THE SHORT TERM PERIOD. COLD
FRONT WILL BE TO THE EAST OF THE CWA SUNDAY MORNING...WITH UPPER
TROUGH ACROSS THE EASTERN U.S....AND SURFACE HIGH PRESSURE GRADUALLY
TRYING TO PUSH IN FROM THE WEST. WILL STILL BE SOME CLOUDS LINGERING
OVER EASTERN COUNTIES EARLY SUNDAY...BUT AT LEAST SOUTHEAST OHIO
ZONES SHOULD SEE SOME PARTIAL CLEARING. MUCH DRIER AIR WILL BEGIN TO
FILTER IN BEHIND THE FRONT...WITH DEW POINTS DIPPING INTO THE LOWER
50S TO UPPER 40S SUNDAY INTO MONDAY. WITH THE CLEAR SKY EXPECTED
OVERNIGHT SUNDAY INTO MONDAY...ALONG WITH CALM SURFACE WINDS AND THE
DRIER AIR IN PLACE...KEPT LOW TEMPERATURES MONDAY MORNING BELOW
GUIDANCE...WITH MANY LOWLANDS DIPPING INTO THE 50S. HOWEVER...FOG
DEVELOPMENT WILL BE LIKELY THAT MORNING...WHICH COULD MITIGATE THE
COOLING SOMEWHAT...THUS LEADING TO A POTENTIAL FOR A BUSTED LOW
TEMPERATURE FORECAST MONDAY MORNING.
UPPER TROUGH AND SURFACE HIGH WILL SLIDE OFF TO THE EAST MONDAY INTO
TUESDAY...AS THE NEXT SYSTEM APPROACHES FROM THE WEST. WITH THE FLOW
TURNING MORE SOUTHERLY...EXPECT WARMER TEMPERATURES AND MORE HUMID
AIR MOVING INTO THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ZONAL FLOW MARKS THE BEGINNING OF THE EXTENDED PERIOD WITH A WEAK
IMPULSE POISED TO MOVE THROUGH CWA DAYS 4 AND 5. KEEPING HIGH CHC
POPS ASSOCIATED WITH THIS IMPULSE AS THERE IS NOT ENOUGH CONFIDENCE
IN THE TIMING OR TRACK OF THIS WAVE. 00Z ECMWF IS A BIT SLOWER AND
FURTHER SOUTH THAN THE 06Z AND 12Z GFS RUNS...HOWEVER...THE 12Z GFS
IS HEDGING FURTHER SOUTH PASSING THE H5 VORT THROUGH CENTRAL KY AND
ERN TN. ENOUGH MOISTURE FROM THE UPPER SYSTEM TO THE NORTH WILL
SHOULD ALLOW FOR AT LEAST A SLIGHT CHC OF SHOWERS AND MAYBE EVEN
THUNDER DAY 6. OTHERWISE...A MOSTLY DRY AND SEASONABLE EXTENDED
PERIOD IN OUR NECK OF THE WOODS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
NUMEROUS SHOWERS WITH A FEW THUNDERSTORMS POSSIBLE AHEAD OF A
STRONG COLD FRONT TODAY. CHANCES FOR SHOWERS CONTINUE INTO TONIGHT
WITH THE COD FRONT ITSELF.
THROUGH THE REMAINDER OF TODAY...SOME CLEARING OVER THE WESTERN
LOWLANDS HAS ALLOWED THE CAPE TO SPIKE...AND NOW ARE SEEING A
COUPLE LIGHTNING STRIKES IN THE NORTH CENTRAL PART OF WEST
VIRGINIA. NO PREVAILING TSRA FOR THE TERMINALS...JUST USING
VCTS/CB THROUGH EVENING.
CARRYING A TEMPO IFR OFF THE BAT FOR EKN IN STEADIER RAIN WITH
PREVAILING MVFR VISIBILITIES.
EXPECTING A LOW STRATUS DECK TO MATERIALIZE BEHIND THE FRONT
SUNDAY...WITH MVFR CEILINGS POSSIBLE BENEATH THE ELEVATED
INVERSION LAYER. STILL MAY HAVE TO DODGE A SHOWER OR TWO SOUTHEAST
OF THE OHIO RIVER EARLY SUNDAY. LOW STRATUS DECK ERODES AFTER 18Z
FOR THE LOWLANDS...BUT COULD LINGER IN THE MOUNTAINS INTO SUNDAY
EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MAY NEED A FEW MORE TEMPO AMENDMENTS IN
SHRA/TSRA TODAY. TIMING OF COLD FRONT AND ENDING SHOWERS 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 H H H H H H H M M M
HTS CONSISTENCY H H H H H H H H M M H H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY H H H H M H H H M M H H
PKB CONSISTENCY H H H H H M M M M M H M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 18Z SUNDAY...
IFR IN VALLEY FOG MONDAY AND TUESDAY MORNINGS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...SL
LONG TERM...TAX
AVIATION...26
AREA FORECAST DISCUSSION
NWS MEDFORD OR
252 PM PDT SAT JUL 27 2013
.DISCUSSION...AN UPPER TROUGH IS APPROACHING THE FORECAST AREA
TODAY...AND IS IMPACTING OUR WEATHER IN SEVERAL WAYS.
FIRST...TEMPERATURES ARE ABOUT 5 TO 10 DEGREES COOLER THAN
YESTERDAY AT THIS TIME AS THE AIR MASS BECOMES DRIER AND COOLER.
SECOND...WINDS ARE INCREASING ACROSS THE FORECAST AREA THIS
AFTERNOON IN RESPONSE TO TIGHTENING ONSHORE PRESSURE
GRADIENTS...LIKELY CAUSING SEVERAL FIRES IN THE REGION TO BECOME
MORE ACTIVE. THIRD...GIVEN THE LIGHT TO MODERATE NORTH WINDS
ALOFT...SMOKE FROM THE FIRES IS SPREADING TO THE SOUTH INTO MOSTLY
JACKSON...JOSEPHINE...CURRY...AND SISKIYOU COUNTIES.
LINGERING INSTABILITY MAY PRODUCE SOME THUNDERSTORMS OVER NORTHERN
CALIFORNIA TODAY...BUT STABILITY AND A VERY DRY AIR MASS SHOULD
PREVENT THUNDERSTORMS FROM FORMING ELSEWHERE. THE LATEST HRRR MODEL
RUN CONFIRMS THIS IDEA...AND THIS MODEL HAS DONE FAIRLY WELL OVER
THE PAST COUPLE DAYS FOR AFTERNOON THUNDERSTORM ACTIVITY.
AS THE DAYS PROGRESS, BREEZY AFTERNOON CONDITIONS WILL
CONTINUE...WITH WINDS PEAKING ON THE WEST SIDE TODAY AND
SUNDAY...AND PEAKING ON THE EAST SIDE SUNDAY AND MONDAY. WINDS ALOFT
WILL LIKELY SWITCH TO A MORE WESTERLY DIRECTION BY MONDAY...PERHAPS
SHIFTING SMOKE FROM FIRES TOWARD THE EAST MORE THAN THE CURRENT
SITUATION. ADDITIONALLY...THE MARINE LAYER WILL GRADUALLY DEEPEN
ALONG THE COAST...PUSHING CLOUDS FARTHER AND FARTHER INLAND EACH
MORNING. THESE CLOUDS WILL LIKELY REACH ROSEBURG BY MONDAY MORNING
AND PERHAPS AS EARLY AS TOMORROW MORNING.
TEMPERATURES WILL LIKELY STABILIZE SUNDAY INTO EARLY NEXT
WEEK...WITH READINGS AROUND NORMAL FOR THIS TIME OF YEAR.
BY TUESDAY AND WEDNESDAY...MODELS ARE IN GOOD AGREEMENT ABOUT A
SIGNIFICANT CLOSED UPPER LOW DROPPING IN FROM THE
NORTHWEST...BRINGING ANOTHER ROUND OF COOLING. TEMPERATURES WILL
LIKELY DROP BELOW NORMAL BY MIDWEEK. MARINE CLOUDS SHOULD STICK
AROUND THE COAST AND CONTINUE TO REACH THE UMPQUA BASIN LATE AT
NIGHT AND EARLY IN THE MORNING...AND AT LEAST INFLUENCE THE FIRES IN
DOUGLAS AND JOSEPHINE COUNTY WITH SOME HIGHER HUMIDITIES. ITS
UNLIKELY THE TROUGH WILL BE STRONG ENOUGH TO MIX OUT THE MARINE
LAYER...BUT IT IS AN OUTSIDE CHANCE.
AHEAD OF THIS CLOSED LOW ON TUESDAY THROUGH THURSDAY...MODELS
SUGGEST SOME INSTABILITY EAST OF THE CASCADES. WE HAVE BUMPED UP
POPS SOME...BUT HAVE LEFT OUT ANY PRECIPITATION FOR THE TIME BEING.
INSTABILITY IS MARGINAL AND WOULD LIKE TO SEE A FEW MORE MODEL RUNS
BEFORE PLACING SHOWERS OR THUNDERSTORMS EAST OF THE CASCADES.
&&
.AVIATION...NORTHWEST WINDS ARE BECOMING GUSTY THIS AFTERNOON
ACROSS THE FORECAST AREA. THUNDERSTORMS MAY FORM LATER THIS
AFTERNOON OVER NORTHERN CALIFORNIA AND WILL DIMINISH TONIGHT.
SMOKE WILL CONTINUE TO DRIFT SOUTH FROM SOUTHERN DOUGLAS COUNTY
INTO CURRY...JOSEPHINE...JACKSON...AND SISKIYOU COUNTIES...AND MAY
SPREAD AS FAR EAST AS KLAMATH COUNTY THIS EVENING.
ALONG THE COAST...MARINE STRATUS WILL FILL BACK IN MOSTLY NORTH OF CAPE
BLANCO WITH IFR CONDITIONS LIKELY TONIGHT...SPREADING INTO THE
COASTAL VALLEY EARLY SUNDAY MORNING. ANY COASTAL STRATUS SHOULD
CLEAR BY LATE SUNDAY MORNING.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR ORZ031.
CA...NONE.
PACIFIC COASTAL WATERS...GALE WARNING UNTIL 8 PM PDT THIS EVENING FOR PZZ356.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SUNDAY FOR
PZZ350-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SUNDAY
FOR PZZ370.
GALE WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ376.
HAZARDOUS SEAS WARNING UNTIL 11 AM PDT MONDAY FOR PZZ376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SUNDAY
FOR PZZ350.
$$
NSK/NSK/NSK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
111 PM CDT SAT JUL 27 2013
.UPDATE...FOR 18Z TAFS.
&&
.AVIATION...
WEAK COLD FRONT EXPECTED TO MOVE SLOWLY ACROSS THE MID-STATE THIS
AFTERNOON/TONIGHT. THIS WILL PRODUCE ISO-SCT STORMS BUT LARGELY
EAST OF BNA THRU 02Z. CEILINGS/VSBYS WILL STAY IN VFR RANGE WELL
INTO TONIGHT BARRING A DIRECT HIT AND THAT IS MAINLY CONCERNING
CSV. CLEARING SKIES OVERNIGHT WILL ALLOW FOG TO DEVELOP BEHIND
BOUNDARY. CONDITIONS MOST LIKELY MVFR LATE NIGHT HOURS CKV/BNA BUT
CSV CEILING/VSBYS EXPECTED TO DROP INTO IFR RANGE. ALL SITES
VFR BY 15Z MON.
&&
.PREV DISCUSSION... /ISSUED 514 AM CDT SAT JUL 27 2013/
UPDATE...
12Z TAF DISCUSSION.
AVIATION...
SCATTERED LIGHT RAIN SHOWERS CONTINUE TO SPREAD ACROSS CKV/BNA
THIS MORNING AND WILL BE NEAR CSV OVER THE NEXT FEW
HOURS...WARRANTING VCSH MENTION AT ALL AIRPORTS. SHORT TERM
GUIDANCE INDICATES A BREAK IN PRECIP BEFORE MORE SCATTERED SHOWERS
DEVELOP THIS AFTERNOON/EVENING AS COLD FRONT APPROACHES. VFR CIGS
ANTICIPATED THROUGH TAF PERIOD WITH LIGHT WEST WINDS BECOMING
NORTHWEST AFTER FROPA.
SHAMBURGER
PREV DISCUSSION... /ISSUED 342 AM CDT SAT JUL 27 2013/
DISCUSSION...
SHOWERS HAVE BEEN MOVING INTO THE WEST HALF OF MIDDLE TN EARLY
THIS MORNING AS A WEAK H5 TROF MOVES INTO THE REGION. TROF SHOULD
MOVE EAST OF THE REGION WITHIN THE NEXT FEW HOURS AND HRRR SHOWS
THESE SHOWERS ENDING LATER THIS MORNING.
VERY UNUSUAL FORECAST FOR MID SUMMER. H5 CLOSED LOW WILL MOVE
SLOWLY EAST THRU THE GREAT LAKES THIS WEEKEND. ASSOCIATED SFC LOW
WILL HELP BRING A COLD FRONT INTO NW MIDDLE TN LATE TODAY...AND TO
THE REST OF THE AREA BY MIDNIGHT. SCATTERED SHOWERS AND MAYBE A
FEW STORMS WILL REDEVELOP THIS AFTERNOON AND EARLY EVENING AHEAD
OF THE FRONT. RAINFALL AMOUNTS WILL BE LIGHT WITH LESS THAN 1/4
INCH IN MOST AREAS.
COOLER AND DRY WEATHER ON TAP FOR SUN/MON AS SFC RIDGE SETTLES
INTO MID TN. MONDAY MORNING MIN TEMPS COULD APPROACH RECORDS.
GFS GUIDANCE IS AN OUTLIER BY FORECASTING 2 DEGREES COLDER THAN
THE RECORD AT BNA...AND A WHOPPING 5 DEGREES COLDER THAN THE
RECORD AT CSV. SO...LEANED MORE TOWARD THE WARMER AND SEEMINGLY
MORE REASONABLE NAM/ECMWF GUIDANCE.
H5 HEIGHTS REBOUND BY TUESDAY AS GREAT LAKES LOW MOVES FURTHER
AWAY AND RIDGE REBUILDS ACROSS THE SOUTHERN U.S. HOWEVER...GFS AND
ECMWF SHOW WEAK NW FLOW ALOFT WITH A TROF APPROACHING THE MID
STATE TUE/WED...FOLLOWED BY ANOTHER BUT WEAKER COLD FRONT LATE
WEDNESDAY. WITH MEAN RH AND LIFT INCREASING...WILL GO WITH CHANCE
TYPE POPS TUESDAY THRU WEDNESDAY EVENING. GFS AND ECMWF BOTH SHOW
SIGNIFICANT QPF BULLS EYES BUT MAINLY IN SOUTHERN KY.
AFTER THE TROF MOVES AWAY...SOME DRYING IS EXPECTED THURSDAY AND
FRIDAY WITH TEMPS UP A FEW DEGREES AS THICKNESS/HEIGHTS EDGE
UPWARD. RAIN CHANCES MAY INCREASE AGAIN NEXT WEEKEND AS BOTH
MODELS SHOW YET ANOTHER WEAK FRONT MOVING SLOWLY INTO MIDDLE TN
FROM THE NORTH.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07