Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/14/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
248 PM MST FRI JUL 12 2013
.SYNOPSIS...WITH A BIT LESS ATMOSPHERIC MOISTURE OVER THE AREA EACH
DAY THROUGH SUNDAY THE SHOWER AND THUNDERSTORM ACTIVITY WILL
DIMINISH SOMEWHAT THROUGH THE WEEKEND WITH HIGH TEMPERATURES SLOWLY
RISING. THEN A WEATHER SYSTEM FROM THE PLAINS STATES WILL MOVE WEST
AND BEGIN TO AFFECT OUR WEATHER EARLY NEXT WEEK WITH MORE MOISTURE
AND INSTABILITY. THIS WILL INCREASE THE THREAT OF SHOWERS AND
THUNDERSTORMS MONDAY ONWARD WITH HIGH TEMPERATURES COOLING OFF A BIT
ONCE AGAIN.
&&
.DISCUSSION...WELL TODAY WAS INTERESTING. A WONDERFUL MCS PUSHED
NORTH ACROSS PIMA AND PINAL COUNTIES PROVIDING WIDESPREAD BENEFICIAL
RAINFALL. REPORTS GENERALLY RANGED FROM AROUND A TENTH UP TO A HALF
INCH ACROSS TUCSON...WITH THE MAX REPORTS AROUND FLORANCE WITH
OVER 2.5 INCHES OBSERVED. THINKING THE ATMOSPHERE IS NOW PRETTY
WORKED OVER IN THE CENTRAL ZONES SO THE BEST SHOT AT ANY CONVECTION
THIS AFTERNOON WOULD BE OVER COCHISE AND UP THROUGH GRAHAM AND
GREENLEE COUNTIES. ISOLATED ACTIVITY CAN NOT BE RULED OUT IN PIMA
AND COCHISE COUNTIES GIVEN THE RAPID WARMING WE HAVE EXPERIENCED IN
THE LAST FEW HOURS. THE HRRR ONLY HINTS AT A FEW STORMS THOUGH SO I
LOWERED PRECIP CHANCES A LITTLE THROUGH MIDNIGHT.
MODELS CONTINUE TO SHOW A DRYING TREND THROUGH SUNDAY. MID LEVEL DRY
AIR ADVECTION BRINGS OUR PRECIPITABLE WATER VALUES DOWN A FEW TENTHS
TOMORROW BUT THAT STILL LEAVES PLENTY OF MOISTURE FOR STORMS GIVEN
ENOUGH DAYTIME HEATING. WE ARE EXPECTING BETTER HEATING TOMORROW
ESPECIALLY IF WE CAN KEEP THE SKY CLEAR DURING THE MORNING HOURS.
MODELS SHOW LESS ACTIVITY OVER THE SIERRA MADRES TONIGHT SO THAT
WOULD SUGGEST FEWER CLOUDS IN THE MORNING. PLUS...THEIR IS A WEAK
PVU ANOMALY THAT MOVES INTO SE AZ AROUND 00Z SUNDAY. WRF DATA BREAKS
OUT PRECIP AROUND 3 PM TOMORROW AND THAT SEEMS REASONABLE.
MID LEVEL FLOW REALLY PULLS IN DRIER AIR SUNDAY AND DROPS OUR
PRECIPITABLE WATER VALUES DOWN TO AROUND 1.3 INCHES. THIS IS A
RESULT OF THE MONSOON RIDGE SPLITTING INTO TWO LOBES WITH ONE HIGH
PARKING OVER AZ/NM REGION WITH THE SECOND HIGH OVER THE NORTHEAST
UNITED STATES. WE SHOULD SEE A WARMING TREND IN ADDITION TO THE
DRIER CONDITIONS.
AFTER THAT...OUR PATTERN HAS THE POTENTIAL TO BECOME WET BY TUESDAY.
HERE IS WHAT WE DO KNOW ABOUT THE MID WEEK SYSTEM. FIRST...THE
OPERATIONAL GFS/ECMWF/CANADIAN ALL SHOW AN EASTERLY MOVING TROUGH AT
AROUND 40 DEG. LATITUDE STARTING OVER OHIO VALLEY ON SATURDAY AND
REACHING NEW MEXICO BY TUE. ENSEMBLE DATA SUPPORT THIS IDEA AS WELL.
WE ALSO KNOW THE MODELS ARE PROJECTING INCREASED MOISTURE WITH THIS
SYSTEM. MY CONCERN IS THE MOISTURE SOURCE. IT APPEARS THE MODELS ARE
TRYING TO RECYCLE THE MOISTURE AS IT TRAVELS AROUND OUR RIDGE THIS
WEEKEND. THE MOIST AIR TRAVELS NORTH INTO CANADA...THEN MOVES
SOUTH OVER COLORADO AND NEW MEXICO AS THE HIGH SPLITS AND PROVIDES
MORE NORTHEAST FLOW ALOFT INTO THE SW UNITED STATES. I WOULD THINK
SOME OF THE MOISTURE WOULD DISSIPATE ALONG THIS TRACK BUT THE MODELS
ARE ADAMANT THAT MOISTURE WILL BE AVAILABLE. EVENTUALLY...THERE IS A
MID LEVEL MOISTURE TAP INTO THE GULF OF MEXICO BUT THAT WOULD BE
LATE WEDNESDAY INTO THURSDAY.
SO WITH THAT IN MIND...I INCREASED RAIN CHANCES BY 5 OR 10 PERCENT
ON TUESDAY AND WEDNESDAY AND I AM CONCERNED THAT HEAVY RAIN WILL BE
POSSIBLE SOMETIME NEXT WEEK. THE EXACT TIME AND LOCATIONS ARE STILL
UP IN THE AIR THOUGH. IF THE GFS IS RIGHT...THEN WE NEED TO WATCH
FOR HEAVY RAIN AND FLOODING ON TUESDAY AND WEDNESDAY BUT COULD START
AS EARLY AS MONDAY NIGHT. EITHER WAY...NEXT WEEK LOOKS VERY
INTERESTING.
JJB
&&
.AVIATION...THUNDERSTORM ACTIVITY WILL BE LIMITED THROUGH THE
EVENING HOURS BUT SHOWERS OR THUNDERSTORMS MAY REDEVELOP AFTER 04Z.
OUTSIDE OF THE STORMS...VFR CIGS ARE ANTICIPATED WITH BKN100-120
DEVELOPING AFTER 04Z. WINDS WILL FOLLOW NORMAL DIURNAL TRENDS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY AFTERNOON THROUGH EARLY MORNING
SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A DIMINISHING
TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL PRODUCE
GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF THE
THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. DAYTIME RELATIVE HUMIDITIES
WILL RANGE FROM THE 20S TO 40S WITH GOOD NIGHTTIME RECOVERIES. A
SLIGHT DRYING TREND IS EXPECTED LATE THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
227 PM MST FRI JUL 12 2013
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
MOIST MONSOON AIR UNDER FAVORABLE SOUTHERLY FLOW WILL CONTINUE INTO
THIS EVENING...WITH SCATTERED TO NUMEROUS THUNDERSTORMS EXPECTED
OVER SOUTH CENTRAL ARIZONA...WITH ISOLATED THUNDERSTORMS ELSEWHERE.
DRIER AIR WILL BEGIN TO SLIDE INTO THE REGION ON SATURDAY...AND
ESPECIALLY ON SUNDAY AND MONDAY...WITH CHANCES OF SHOWERS AND
THUNDERSTORMS DECREASING EACH DAY. TEMPERATURES WILL BE WARMING TO
NEAR...OR ABOVE NORMAL VALUES NORMAL FOR THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.DISCUSSION...
AFTER A RATHER QUIET MORNING...A RATHER ACTIVE AFTERNOON
WEATHERWISE APPEARS TO BE ON TAP FOR SOUTH CENTRAL ARIZONA THIS
AFTERNOON AND EVENING. AS DEPICTED ON THE LAST SEVERAL RUNS OF THE
HOURLY HRRR MODEL...A LARGE COMPLEX OF THUNDERSTORMS THAT FORMED
LATE LAST NIGHT OVER NORTHERN SONORA MEXICO HAS HELD TOGETHER QUITE
WELL AND IS NOW PRODUCING A LINE OF STRONG THUNDERSTORMS THAT IS NOW
MOVING ACROSS PINAL COUNTY. THIS COMPLEX OF STORMS APPEARS TO BE
BEING SUPPORTED BY A SHORTWAVE/JET MAX THAT WAS PICKED UP ON THE 12Z
500MB ANALYSIS OVER SOUTHEAST ARIZONA. THESE STORMS HAVE ALREADY
PRODUCED DAMAGING WINDS...BLOWING DUST...SMALL HAIL...AND LOCAL
RAINFALL AMOUNTS IN EXCESS OF 1 INCH OVER PIMA AND PINAL COUNTIES.
LATEST HIGH-RESOLUTION MODEL RUNS TAKE THESE STORMS INTO THE GREATER
PHOENIX AREA THIS AFTERNOON...THEN RAPIDLY WEAKEN THEM THIS EVENING
AS THEY MAKE AN ATTEMPT TO PUSH INTO WESTERN ARIZONA AS THE
SUPPORTING SHORTWAVE RAPIDLY MOVES OFF TO THE NORTH AND WEAKENS.
SATURDAY APPEARS TO BE SETTING UP AS A QUIETER DAY...ESPECIALLY IF
TODAY`S THUNDERSTORM ACTIVITY WORKS OVER THE AIRMASS OVER THE
REGION. MODEL GUIDANCE IS IS GOOD AGREEMENT THAT RIDGING WILL BUILD
BACK WESTWARD INTO THE DESERT SOUTHWEST AS AN UPPER TROF MOVES INTO
THE PACIFIC NORTHWEST. LATEST NAM FORECAST SOUNDINGS DROP THE PWAT
VALUES OVER THE PHOENIX AREA TO AROUND 1.6 INCH ON SATURDAY
AFTERNOON...1.3 INCH ON SUNDAY AFTERNOON...AND 1.1 INCH ON MONDAY
AFTERNOON. CURRENT THINKING IS THAT THUNDERSTORM ACTIVITY WILL BE
CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON
SATURDAY...WITH LITTLE OR NO ACTIVITY ON SUNDAY AND MONDAY.
TEMPERATURES ARE EXPECTED TO WARM EACH DAY...WITH HIGHS APPROACHING
110F BY MONDAY.
ALTHOUGH WE ARE NOT COMPLETELY SOLD ON THE LONG RANGE MODEL
SOLUTIONS FOR THE MIDDLE OF NEXT WEEK...IT DOES LOOK LIKE A FAIRLY
SIGNIFICANT UPPER LOW MAY MAKE IT/S WAY ACROSS THE SOUTHERN PLAINS
INTO NEW MEXICO BY NEXT TUESDAY. IT IS TOO EARLY TO KNOW HOW MUCH
MOISTURE WILL BE AVAILABLE ACROSS THE REGION...BUT IF THIS SOLUTION
PANS OUT...THE MIDDLE OF NEXT WEEK COULD SEE VERY ACTIVE MONSOON
ACTIVITY ACROSS EASTERN ARIZONA AND POSSIBLY INTO THE LOWER DESERTS.
THE OVERALL FLOW DURING THIS TIME WILL LIKELY BE FROM THE NORTHEAST
ACROSS EASTERN ARIZONA AND FROM THE SOUTH ACROSS FAR WESTERN
ARIZONA. A SCENARIO LIKE THIS WOULD LIKELY RESULT IN DRY CONDITIONS
TO THE WEST OF PHOENIX AND AN ACTIVE MONSOON PERIOD ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. THE LONG RANGE TEMPERATURE OUTLOOK
SHOULD BRING NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES ACROSS OUR
WESTERN ZONES AND NEAR TO SLIGHTLY BELOW NORMAL FOR SOUTH-CENTRAL
AND EAST-CENTRAL ARIZONA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
BLOWING DUST HAS MOVED THROUGH ALL PHOENIX SITES...AND VSBYS SHOULD
GRADUALLY IMPROVE THROUGH 00Z. SOME LIGHT RAIN SHOWERS ALSO POSSIBLE
AT ALL PHOENIX SITES BUT SHOULD DISSIPATE QUICKLY. WINDS WILL REMAIN
SOUTHEASTERLY FOR THE DURATION OF THE AFTERNOON AND EVENING.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...MAINLY
LOOKING AT BLOWOFF HIGH CLOUDS ACROSS SE CA. CHANCES OF PRECIP AT
BOTH SITES IS SLIM...ONLY GOING TO MENTION SCT-BKN250. WINDS WILL
FAVOR TYPICAL DIURNAL PATTERNS THROUGH SATURDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
STORM CHANCES WILL GRADUALLY RETURN TO THE AREA EARLY NEXT WEEK. BY
TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM VALUES WILL IMPROVE...ONLY
DROPPING INTO THE 20-30 PERCENT RANGE WITH ANOTHER INCREASE IN
MOISTURE. OVERNIGHT RECOVERY SHOULD BE GOOD TO EXCELLENT WITH
READINGS CLIMBING ABOVE 40 PERCENT MOST NIGHTS. DAYTIME GUSTY WINDS
ARE POSSIBLE EACH DAY...ALONG WITH POSSIBLE THUNDERSTORM OUTFLOW
BOUNDARY WINDS ON SATURDAY AND AGAIN TUESDAY AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
120 PM MST FRI JUL 12 2013
&&
.SYNOPSIS...
MOIST MONSOON AIR UNDER FAVORABLE SOUTHERLY FLOW WILL CONTINUE INTO
THIS EVENING...WITH SCATTERED TO NUMEROUS THUNDERSTORMS EXPECTED
OVER SOUTH CENTRAL ARIZONA...WITH ISOLATED THUNDERSTORMS ELSEWHERE.
DRIER AIR WILL BEGIN TO SLIDE INTO THE REGION ON SATURDAY...AND
ESPECIALLY ON SUNDAY AND MONDAY...WITH CHANCES OF SHOWERS AND
THUNDERSTORMS DECREASING EACH DAY. TEMPERATURES WILL BE WARMING TO
NEAR...OR ABOVE NORMAL VALUES NORMAL FOR THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.DISCUSSION...
AFTER A RATHER QUIET MORNING...A RATHER ACTIVE AFTERNOON
WEATHERWISE APPEARS TO BE ON TAP FOR SOUTH CENTRAL ARIZONA THIS
AFTERNOON AND EVENING. AS DEPICTED ON THE LAST SEVERAL RUNS OF THE
HOURLY HRRR MODEL...A LARGE COMPLEX OF THUNDERSTORMS THAT FORMED
LATE LAST NIGHT OVER NORTHERN SONORA MEXICO HAS HELD TOGETHER QUITE
WELL AND IS NOW PRODUCING A LINE OF STRONG THUNDERSTORMS THAT IS NOW
MOVING ACROSS PINAL COUNTY. THIS COMPLEX OF STORMS APPEARS TO BE
BEING SUPPORTED BY A SHORTWAVE/JET MAX THAT WAS PICKED UP ON THE 12Z
500MB ANALYSIS OVER SOUTHEAST ARIZONA. THESE STORMS HAVE ALREADY
PRODUCED DAMAGING WINDS...BLOWING DUST...SMALL HAIL...AND LOCAL
RAINFALL AMOUNTS IN EXCESS OF 1 INCH OVER PIMA AND PINAL COUNTIES.
LATEST HIGH-RESOLUTION MODEL RUNS TAKE THESE STORMS INTO THE GREATER
PHOENIX AREA THIS AFTERNOON...THEN RAPIDLY WEAKEN THEM THIS EVENING
AS THEY MAKE AN ATTEMPT TO PUSH INTO WESTERN ARIZONA AS THE
SUPPORTING SHORTWAVE RAPIDLY MOVES OFF TO THE NORTH AND WEAKENS.
SATURDAY APPEARS TO BE SETTING UP AS A QUIETER DAY...ESPECIALLY IF
TODAY`S THUNDERSTORM ACTIVITY WORKS OVER THE AIRMASS OVER THE
REGION. MODEL GUIDANCE IS IS GOOD AGREEMENT THAT RIDGING WILL BUILD
BACK WESTWARD INTO THE DESERT SOUTHWEST AS AN UPPER TROF MOVES INTO
THE PACIFIC NORTHWEST. LATEST NAM FORECAST SOUNDINGS DROP THE PWAT
VALUES OVER THE PHOENIX AREA TO AROUND 1.6 INCH ON SATURDAY
AFTERNOON...1.3 INCH ON SUNDAY AFTERNOON...AND 1.1 INCH ON MONDAY
AFTERNOON. CURRENT THINKING IS THAT THUNDERSTORM ACTIVITY WILL BE
CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON
SATURDAY...WITH LITTLE OR NO ACTIVITY ON SUNDAY AND MONDAY.
TEMPERATURES ARE EXPECTED TO WARM EACH DAY...WITH HIGHS APPROACHING
110F BY MONDAY.
ALTHOUGH WE ARE NOT COMPLETELY SOLD ON THE LONG RANGE MODEL
SOLUTIONS FOR THE MIDDLE OF NEXT WEEK...IT DOES LOOK LIKE A FAIRLY
SIGNIFICANT UPPER LOW MAY MAKE IT/S WAY ACROSS THE SOUTHERN PLAINS
INTO NEW MEXICO BY NEXT TUESDAY. IT IS TOO EARLY TO KNOW HOW MUCH
MOISTURE WILL BE AVAILABLE ACROSS THE REGION...BUT IF THIS SOLUTION
PANS OUT...THE MIDDLE OF NEXT WEEK COULD SEE VERY ACTIVE MONSOON
ACTIVITY ACROSS EASTERN ARIZONA AND POSSIBLY INTO THE LOWER DESERTS.
THE OVERALL FLOW DURING THIS TIME WILL LIKELY BE FROM THE NORTHEAST
ACROSS EASTERN ARIZONA AND FROM THE SOUTH ACROSS FAR WESTERN
ARIZONA. A SCENARIO LIKE THIS WOULD LIKELY RESULT IN DRY CONDITIONS
TO THE WEST OF PHOENIX AND AN ACTIVE MONSOON PERIOD ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. THE LONG RANGE TEMPERATURE OUTLOOK
SHOULD BRING NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES ACROSS OUR
WESTERN ZONES AND NEAR TO SLIGHTLY BELOW NORMAL FOR SOUTH-CENTRAL
AND EAST-CENTRAL ARIZONA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
CONVECTION TRYING TO WORK ITS WAY INTO THE METRO AREA FROM THE
SOUTH...BUT AS HAS BEEN THE CASE FOR THE PAST FEW DAYS...STORMS SEEM
TO BE DECAYING AS THEY DESCEND INTO THE DESERTS AND ENCOUNTER THE
MID LEVEL CAPPING INVERSION. THAT BEING SAID...HRRR MODEL AND TO
SOME EXTENT THE U-OF-A WRF MODELS TRY AND BRING THIS CONVECTION
INTO THE EAST VALLEY LATER THIS AFTERNOON. INTRODUCED VCSH AT ALL
PHOENIX TAF SITES BETWEEN 19-21Z ALTHOUGH MY CONFIDENCE IN
PREVAILING -SHRA REMAINS LOW. IF NOTHING ELSE...WIDESPREAD CIGS
BETWEEN 6-8KFT ARE LIKELY ACROSS THE AREA THIS AFTERNOON/EVENING.
WINDS WILL REMAIN WESTERLY UNTIL EARLY EVENING...BANKING ON OUTFLOWS
TO TURN THEM AROUND OUT OF THE EAST BY MID EVENING.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
MAINLY LOOKING AT BLOWOFF HIGH CLOUDS ACROSS SE CA. CHANCES OF
PRECIP AT BOTH SITES IS SLIM...ONLY GOING TO MENTION SCT-BKN250.
WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS THROUGH SATURDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A DRYING TREND WILL KEEP STORM CHANCES MAINLY CONFINED TO THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX SUNDAY AND MONDAY. MINIMUM
HUMIDITY VALUES IN THE TEENS WILL PERSIST ACROSS THE LOWER DESERTS
FOR SUNDAY AND MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM
VALUES WILL IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE
WITH ANOTHER INCREASE IN MOISTURE. OVERNIGHT RECOVERY SHOULD BE GOOD
TO EXCELLENT WITH READINGS CLIMBING ABOVE 40 PERCENT MOST NIGHTS.
DAYTIME GUSTY WINDS ARE POSSIBLE EACH DAY...ALONG WITH POSSIBLE
THUNDERSTORM OUTFLOW BOUNDARY WINDS ON SATURDAY AND AGAIN TUESDAY
AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...DUST STORM WARNING PHOENIX METRO AREA UNTIL 3PM TODAY. SEVERE
THUNDERSTORM WARNING NORTHERN PINAL AND SOUTHEAST MARICOPA COUNTY
UNTIL 1PM TODAY.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CDEWEY
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
1036 AM MST FRI JUL 12 2013
.UPDATE...UPDATED AVIATION DISCUSSION...
&&
.SYNOPSIS...
MOIST MONSOON AIR UNDER FAVORABLE SOUTHERLY FLOW WILL CONTINUE INTO
THE WEEKEND...BUT SOME DRIER AIR WILL BEGIN TO SLIDE EASTWARD INTO
SOUTHWEST ARIZONA BY SUNDAY. CHANCES OF SHOWERS AND THUNDERSTORMS
CONTINUE...BUT WILL GRADUALLY DECREASE ACROSS THE LOWER DESERTS THIS
WEEKEND. THE COOLER TEMPERATURES WILL LAST FOR ANOTHER DAY OR TWO
BEFORE WARMING TO NEAR NORMAL FOR THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
A RATHER QUIET MORNING SO FAR ACROSS THE REGION. LATEST RADAR
IMAGERY IS ONLY SHOWING A FEW SHOWERS AND THUNDERSTORMS MOVING INTO
SOUTHWEST MARICOPA COUNTY...IN THE VICINITY OF GILA BEND...AND A FEW
SHOWERS OVER JOSHUA TREE NATIONAL PARK. A NEW CLUSTER OF
THUNDERSTORMS IS NOW SEEN ON SATELLITE IMAGERY TRYING TO MOVE
NORTHWARD ACROSS THE INTERNATIONAL BORDER INTO EXTREME SOUTHERN
PIMA COUNTY. THE LATEST (13Z) HRRR MODEL RUN WEAKENS THIS NEW
THUNDERSTORM COMPLEX AS IT CONTINUES TO MOVE IT NORTHWARD INTO
SOUTHERN PINAL COUNTY LATE THIS AFTERNOON...THEN BASICALLY
DISSIPATES IT THIS EVENING BEFORE IT REACHES OUR CWA. THIS MODEL
ALSO DEVELOPS SOME SHOWER ACTIVITY OVER GILA COUNTY BETWEEN NOW AND
20Z...THEN SLOWLY WEAKENS THIS ACTIVITY THEREAFTER INTO THE LATE
AFTERNOON AND EVENING HOURS. OTHER THAN SOME MINOR CHANGES IN THE
TEMPERATURE...DEWPOINT...AND POP GRIDS TO REFLECT CURRENT
TRENDS...THE LATEST GRIDDED FORECASTS STILL LOOK GOOD.
&&
.PREVIOUS DISCUSSION...
FOR HAVING SUCH A MOIST AIRMASS IN PLACE ACROSS THE REGION...THE
AMOUNT OF MONSOON ACTIVITY YESTERDAY WAS SOMEWHAT LACKING. THE
EXTENSIVE CLOUDINESS...THE LACK OF ANY FOCUS MECHANISM...AND GENERAL
CONFLUENT FLOW ALOFT ALL LED TO A FAIRLY QUIET MONSOON DAY ACROSS
THE CWA. CURRENT RADAR TRENDS DO SHOW A SMALL CLUSTER OF SHOWERS AND
THUNDERSTORMS MOVING NORTHWESTWARD INTO FAR SOUTHEAST ARIZONA.
HI-RES MODEL REFLECTIVITY INDICATES THIS CLUSTER SHOULD MAKE IT INTO
GILA COUNTY AT AROUND SUNRISE...BUT AT THE SAME TIME BE WEAKENING
CONSIDERABLY. THE REST OF THE AREA...SHOULD STAY DRY THROUGH THE
REST OF THE MORNING HOURS.
TODAY AND SATURDAY ARE EXPECTED TO BE LOW-GRADE MONSOON DAYS EVEN
THOUGH THERE IS AMPLE MONSOON MOISTURE ACROSS THE ENTIRE REGION.
SIMILAR TO YESTERDAY...DAYTIME HEATING WILL BE SOMEWHAT LIMITED DUE
TO THE VERY MOIST SOUNDING PROFILES AND THE EXPECTED CLOUD COVER. WE
SHOULD SEE A BIT MORE THUNDERSTORM ACTIVITY THIS AFTERNOON INTO
TONIGHT...INITIALLY FOCUSED ACROSS THE HIGHER TERRAIN ACROSS EASTERN
ARIZONA AND THEN POSSIBLY TRANSITIONING INTO THE LOWER DESERTS.
CAN/T COMPLETELY RULE OUT SOME STRAY SHOWERS AND THUNDERSTORMS
ANYWHERE ACROSS THE CWA TODAY DUE TO THE WIDESPREAD MOIST
CONDITIONS...BUT THE LACK OF ANY DIVERGENCE ALOFT SHOULD KEEP
DEVELOPMENT ISOLATED. THE MAIN THREAT TODAY WILL BE VERY HEAVY
DOWNPOURS AND A SLIGHT POSSIBILITY OF LOCALIZED FLASH FLOODING. THE
OVERALL WIND THREAT REMAINS LOW DUE TO THE MOIST ATMOSPHERIC
PROFILES.
BY SATURDAY...MODELS INDICATE DRYING WILL START TO WORK INTO
SOUTHEAST CALIFORNIA AND FAR SOUTHWEST ARIZONA VIRTUALLY ELIMINATING
RAIN CHANCES THERE. MAINLY SLIGHT CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE SOUTH-CENTRAL
DESERTS AND HIGHER CHANCES ACROSS THE HIGHER TERRAIN NORTH AND EAST
OF PHOENIX. AS THE DRIER AIR FILTERS INTO THE REGION...TEMPERATURES
WILL BE ON THE RISE...REACHING NEAR OR SLIGHTLY ABOVE SEASONAL
NORMALS SATURDAY INTO EARLY NEXT WEEK. BY SUNDAY...EVEN THE
SOUTH-CENTRAL LOWER DESERTS SHOULD MAINLY BE DRY AS THE DRY FLOW
SLIDES EASTWARD.
ALTHOUGH WE ARE NOT COMPLETELY SOLD ON THE LONG RANGE MODEL
SOLUTIONS FOR THE MIDDLE OF NEXT WEEK...IT DOES LOOK LIKE A FAIRLY
SIGNIFICANT UPPER LOW MAY MAKE IT/S WAY ACROSS THE SOUTHERN PLAINS
INTO NEW MEXICO BY NEXT TUESDAY. IT IS TOO EARLY TO KNOW HOW MUCH
MOISTURE WILL BE AVAILABLE ACROSS THE REGION...BUT IF THIS SOLUTION
PANS OUT...THE MIDDLE OF NEXT WEEK COULD SEE VERY ACTIVE MONSOON
ACTIVITY ACROSS EASTERN ARIZONA AND POSSIBLY INTO THE LOWER DESERTS.
THE OVERALL FLOW DURING THIS TIME WILL LIKELY BE FROM THE NORTHEAST
ACROSS EASTERN ARIZONA AND FROM THE SOUTH ACROSS FAR WESTERN
ARIZONA. A SCENARIO LIKE THIS WOULD LIKELY RESULT IN DRY CONDITIONS
TO THE WEST OF PHOENIX AND AN ACTIVE MONSOON PERIOD ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. THE LONG RANGE TEMPERATURE OUTLOOK
SHOULD BRING NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES ACROSS OUR
WESTERN ZONES AND NEAR TO SLIGHTLY BELOW NORMAL FOR SOUTH-CENTRAL
AND EAST-CENTRAL ARIZONA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
CONVECTION TRYING TO WORK ITS WAY INTO THE METRO AREA FROM THE
SOUTH...BUT AS HAS BEEN THE CASE FOR THE PAST FEW DAYS...STORMS SEEM
TO BE DECAYING AS THEY DESCEND INTO THE DESERTS AND ENCOUNTER THE
MID LEVEL CAPPING INVERSION. THAT BEING SAID...HRRR MODEL AND TO
SOME EXTENT THE U-OF-A WRF MODELS TRY AND BRING THIS CONVECTION
INTO THE EAST VALLEY LATER THIS AFTERNOON. INTRODUCED VCSH AT ALL
PHOENIX TAF SITES BETWEEN 19-21Z ALTHOUGH MY CONFIDENCE IN
PREVAILING -SHRA REMAINS LOW. IF NOTHING ELSE...WIDESPREAD CIGS
BETWEEN 6-8KFT ARE LIKELY ACROSS THE AREA THIS AFTERNOON/EVENING.
WINDS WILL REMAIN WESTERLY UNTIL EARLY EVENING...BANKING ON OUTFLOWS
TO TURN THEM AROUND OUT OF THE EAST BY MID EVENING.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
MAINLY LOOKING AT BLOWOFF HIGH CLOUDS ACROSS SE CA. CHANCES OF
PRECIP AT BOTH SITES IS SLIM...ONLY GOING TO MENTION SCT-BKN250.
WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS THROUGH SATURDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A DRYING TREND WILL KEEP STORM CHANCES MAINLY CONFINED TO THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX SUNDAY AND MONDAY. MINIMUM
HUMIDITY VALUES IN THE TEENS WILL PERSIST ACROSS THE LOWER DESERTS
FOR SUNDAY AND MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM
VALUES WILL IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE
WITH ANOTHER INCREASE IN MOISTURE. OVERNIGHT RECOVERY SHOULD BE GOOD
TO EXCELLENT WITH READINGS CLIMBING ABOVE 40 PERCENT MOST NIGHTS.
DAYTIME GUSTY WINDS ARE POSSIBLE EACH DAY...ALONG WITH POSSIBLE
THUNDERSTORM OUTFLOW BOUNDARY WINDS ON SATURDAY AND AGAIN TUESDAY
AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CDEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST FRI JUL 12 2013
.SYNOPSIS...WITH A BIT LESS ATMOSPHERIC MOISTURE OVER THE AREA EACH
DAY THROUGH SUNDAY THE SHOWER AND THUNDERSTORM ACTIVITY WILL
DIMINISH SOMEWHAT THROUGH THE WEEKEND WITH HIGH TEMPERATURES SLOWLY
RISING. THEN A WEATHER SYSTEM FROM THE PLAINS STATES WILL MOVE WEST
AND BEGIN TO AFFECT OUR WEATHER EARLY NEXT WEEK WITH MORE MOISTURE
AND INSTABILITY. THIS WILL INCREASE THE THREAT OF SHOWERS AND
THUNDERSTORMS MONDAY ONWARD WITH HIGH TEMPERATURES COOLING OFF A BIT
ONCE AGAIN.
&&
.DISCUSSION...OVERNIGHT MCS THAT MOVED ACROSS COCHISE COUNTY INTO
GRAHAM AND GREENLEE COUNTIES HAS ALL BUT DISSIPATED. THIS SYSTEM DID
PRODUCE SOME SOLID RAINFALL SO WE WILL NEED TO WATCH FOR FLOOD
THREATS ACROSS THE SATURATED AREAS TODAY. ADDITIONAL MCS ACTIVITY
OVER THE SIERRA MADRES LAST NIGHT TRIGGERED A SERIES OF OUTFLOWS
THAT IN TURN PRODUCED NEW STORM COMPLEXES DOWNWIND. THE HI RES
MODELS ARE HAVING TROUBLE WITH THE COMPLEX CURRENTLY MOVING INTO
SANTA CRUZ AND PIMA COUNTIES. THE HRRR DID SHOW SOME WEAK STORMS
REACHING FAR SOUTHERN AZ...AND IS CURRENTLY ON TOP OF THE CLOUD
COVER. PLUS...MOISTURE CONTENT IS STILL HIGH SO ANY REMNANT OUTFLOWS
FROM THE MCS OVER SOUTHERN AZ MAY KEEP CONVECTION GOING FOR A FEW
MORE HOURS
WITH THAT IN MIND...I TEND TO FAVOR THE HRRR TODAY WHICH SHOWS A
SIMILAR EVOLUTION AS YESTERDAY. THAT DOES MAKE SENSE GIVEN OUR 12Z
SOUNDING WHICH SHOWS A SIMILAR PROFILE AS YESTERDAY. A THICK VEIL OF
CLOUDS SITS OVER MUCH OF SE AZ AND IT WILL TAKE SOME TIME FOR THE
CLOUDS TO DISSIPATE MEANING OUR SURFACE HEATING POTENTIAL WILL BE
LIMITED. CURRENTLY...WE ARE RUNNING ABOUT A DEGREE WARMER THAN
YESTERDAY...AND THE CONVECTIVE TEMP FOR TODAY SHOULD BE SLIGHTLY
LOWER THAN YESTERDAY. SO I DONT THINK THE MORNING CLOUD COVER WILL
COMPLETELY ELIMINATE STORM CHANCES TODAY...BUT IT MAY KEEP THE
INTENSITY AND COVERAGE DOWN TO MORE ISOLATED TO SCATTERED STORMS.
GIVEN OUR RECENT RAIN IN THE SOUTHERN ZONES AND HI MOISTURE CONTENT
IN THE ATMOSPHERE...I AM AGAIN CONCERNED ABOUT FLOODING. AN ISOLATED
DOWNBURST ALSO IS POSSIBLE AS WE ARE CURRENTLY EXPERIENCING GUSTY
WINDS OUT OF THE SOUTHERN AZ MCS.
JJB
&&
.AVIATION...CONTINUED ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MOVING NNW AT 10-15 KTS THROUGH THIS EVENING OR
08/06Z. ISOLATED CIGS 0F 3-4K FT NEAR THE STRONGER TSTMS WITH VSBYS
POTENTIALLY AS LOW AS 1/2 TO 1SM DUE TO HEAVY RAIN. OUTSIDE OF THE
THUNDERSTORMS...SURFACE WINDS DIURNALLY DRIVEN LESS THAN 10 KTS.
CLOUDS SCT060-080 BKN100-120. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY AFTERNOON THROUGH EARLY MORNING
SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A DIMINISHING
TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL PRODUCE
GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF THE
THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. DAYTIME RELATIVE HUMIDITIES
WILL RANGE FROM THE 20S TO 40S WITH GOOD NIGHTTIME RECOVERIES. A
SLIGHT DRYING TREND IS EXPECTED LATE THIS WEEKEND.
&&
.PREV DISCUSSION...SOME SHOWERS AND THUNDERSTORMS ARE NOW MOVING
ACROSS EXTREME SE AZ EARLY THIS MORNING AND THESE SHOULD CONTINUE
NNW AND SLOWLY DIE OFF OVER THE NEXT SEVERAL HOURS. THEN AS WE MOVE
INTO THE DAY...WITH ABUNDANT LOW LEVEL MOISTURE AND SUFFICIENT
INSTABILITY IN PLACE ACROSS THE REGION...CONVECTION IS EXPECTED TO
FIRE UP LATE THIS MORNING RESULTING IN SCATTERED SHOWERS AND
THUNDERSTORMS FOR THE AFTERNOON AND EVENING HOURS. TIMING OF THE
DEVELOPMENT WILL BE SIMILAR TO YESTERDAY WITH SIMILAR STEERING FLOW
PUSHING THE STORMS TO THE NNW. WITH A BIT LESS MID AND UPPER LEVEL
MOISTURE TO WORK WITH THE STORMS SHOULD BE SLIGHTLY LESS EFFICIENT
RAINFALL PRODUCERS AND WITH A LACK OF A STRONG LIFTING MECHANISM THE
INTENSITIES SHOULD BE HELD IN CHECK FOR THE MOST PART.
THIS THEME CONTINUES INTO THE WEEKEND WITH LOWER LEVELS OF
ATMOSPHERIC MOISTURE FOR THE CONVECTION TO WORK WITH SO WILL HAVE AN
OVERALL TREND OF LESS SHOWER AND STORM COVERAGE EACH DAY AND LESS
INTENSE RAINFALL WITH THE STORMS. HOWEVER...LESS MOISTURE WILL
BRING ABOUT A SOMEWHAT ENHANCED THREAT OF STRONG OUTFLOW WINDS WITH
THE STRONGER STORMS DUE TO A DRIER BOUNDARY LAYER. LESS MOISTURE
ALSO MEANS MORE SUNSHINE RESULTING IN HIGHER AFTERNOON
TEMPERATURES. THE HIGH TEMPERATURES WILL BE A COUPLE OF DEGREES
WARMER EACH DAY THROUGH SUNDAY WITH SUNDAY LIKELY THE WARMEST DAY
BEFORE TEMPS BEGIN TO COOL A BIT AGAIN.
THE AFOREMENTIONED COOL DOWN IS THE RESULT OF AN INTERESTING
SITUATION THAT WILL RESULT IN AN ACTIVE PATTERN NEXT WEEK IF IT
COMES TO PASS AS CURRENTLY MODELED. AN UPPER LEVEL LOW CURRENTLY
CENTERED OVER OHIO IS PROGGED TO MOVE WSW ACROSS THE COUNTY THIS
WEEKEND EVENTUALLY ENDING UP IN THE VICINITY OF NEW MEXICO TOWARD
THE END OF NEXT WEEK. WHILE DEFINITELY NOT THE NORM NEARLY ALL
MODEL SOLUTIONS HAVE PICKED UP ON THIS AND THE LAST FEW HOURS OF THE
WATER VAPOR LOOP SHOWS THE LOW BEGINNING TO TURN TOWARD THE
SOUTHWEST AT THIS TIME. WHAT THIS WOULD RESULT IN IS AN INCREASE IN
DEEP MOISTURE FROM EAST TO WEST BEGINNING MONDAY AND REMAINING OVER
THE AREA THROUGH THE WEEK WITH ENHANCED INSTABILITY JUST FOR ADDED
FUN. WITH THIS SETUP WE WOULD END UP WITH PLENTY OF CONVECTION EACH
DAY THAT WOULD LIKELY LAST WELL INTO THE NIGHT AND THE STORMS WOULD
BE EFFICIENT RAINFALL PRODUCERS DUE TO THE HIGH LEVEL OF
PRECIPITABLE WATER VALUES FORECAST. THE INCREASE IN CONVECTIVE
ACTIVITY AND THE ASSOCIATED CLOUD COVER WILL SUPPRESS AFTERNOON
TEMPERATURES TO A FEW DEGREES BELOW NORMAL TUESDAY ONWARD. WILL BE
INTERESTING TO SEE HOW THIS PLAYS OUT. CERNIGLIA
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS PHOENIX AZ
840 AM MST FRI JUL 12 2013
.SYNOPSIS...
MOIST MONSOON AIR UNDER FAVORABLE SOUTHERLY FLOW WILL CONTINUE INTO
THE WEEKEND...BUT SOME DRIER AIR WILL BEGIN TO SLIDE EASTWARD INTO
SOUTHWEST ARIZONA BY SUNDAY. CHANCES OF SHOWERS AND THUNDERSTORMS
CONTINUE...BUT WILL GRADUALLY DECREASE ACROSS THE LOWER DESERTS THIS
WEEKEND. THE COOLER TEMPERATURES WILL LAST FOR ANOTHER DAY OR TWO
BEFORE WARMING TO NEAR NORMAL FOR THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
A RATHER QUIET MORNING SO FAR ACROSS THE REGION. LATEST RADAR
IMAGERY IS ONLY SHOWING A FEW SHOWERS AND THUNDERSTORMS MOVING INTO
SOUTHWEST MARICOPA COUNTY...IN THE VICINITY OF GILA BEND...AND A FEW
SHOWERS OVER JOSHUA TREE NATIONAL PARK. A NEW CLUSTER OF
THUNDERSTORMS IS NOW SEEN ON SATELLITE IMAGERY TRYING TO MOVE
NORTHWARD ACROSS THE INTERNATIONAL BORDER INTO EXTREME SOUTHERN
PIMA COUNTY. THE LATEST (13Z) HRRR MODEL RUN WEAKENS THIS NEW
THUNDERSTORM COMPLEX AS IT CONTINUES TO MOVE IT NORTHWARD INTO
SOUTHERN PINAL COUNTY LATE THIS AFTERNOON...THEN BASICALLY
DISSIPATES IT THIS EVENING BEFORE IT REACHES OUR CWA. THIS MODEL
ALSO DEVELOPS SOME SHOWER ACTIVITY OVER GILA COUNTY BETWEEN NOW AND
20Z...THEN SLOWLY WEAKENS THIS ACTIVITY THEREAFTER INTO THE LATE
AFTERNOON AND EVENING HOURS. OTHER THAN SOME MINOR CHANGES IN THE
TEMPERATURE...DEWPOINT...AND POP GRIDS TO REFLECT CURRENT
TRENDS...THE LATEST GRIDDED FORECASTS STILL LOOK GOOD.
&&
.PREVIOUS DISCUSSION...
FOR HAVING SUCH A MOIST AIRMASS IN PLACE ACROSS THE REGION...THE
AMOUNT OF MONSOON ACTIVITY YESTERDAY WAS SOMEWHAT LACKING. THE
EXTENSIVE CLOUDINESS...THE LACK OF ANY FOCUS MECHANISM...AND GENERAL
CONFLUENT FLOW ALOFT ALL LED TO A FAIRLY QUIET MONSOON DAY ACROSS
THE CWA. CURRENT RADAR TRENDS DO SHOW A SMALL CLUSTER OF SHOWERS AND
THUNDERSTORMS MOVING NORTHWESTWARD INTO FAR SOUTHEAST ARIZONA.
HI-RES MODEL REFLECTIVITY INDICATES THIS CLUSTER SHOULD MAKE IT INTO
GILA COUNTY AT AROUND SUNRISE...BUT AT THE SAME TIME BE WEAKENING
CONSIDERABLY. THE REST OF THE AREA...SHOULD STAY DRY THROUGH THE
REST OF THE MORNING HOURS.
TODAY AND SATURDAY ARE EXPECTED TO BE LOW-GRADE MONSOON DAYS EVEN
THOUGH THERE IS AMPLE MONSOON MOISTURE ACROSS THE ENTIRE REGION.
SIMILAR TO YESTERDAY...DAYTIME HEATING WILL BE SOMEWHAT LIMITED DUE
TO THE VERY MOIST SOUNDING PROFILES AND THE EXPECTED CLOUD COVER. WE
SHOULD SEE A BIT MORE THUNDERSTORM ACTIVITY THIS AFTERNOON INTO
TONIGHT...INITIALLY FOCUSED ACROSS THE HIGHER TERRAIN ACROSS EASTERN
ARIZONA AND THEN POSSIBLY TRANSITIONING INTO THE LOWER DESERTS.
CAN/T COMPLETELY RULE OUT SOME STRAY SHOWERS AND THUNDERSTORMS
ANYWHERE ACROSS THE CWA TODAY DUE TO THE WIDESPREAD MOIST
CONDITIONS...BUT THE LACK OF ANY DIVERGENCE ALOFT SHOULD KEEP
DEVELOPMENT ISOLATED. THE MAIN THREAT TODAY WILL BE VERY HEAVY
DOWNPOURS AND A SLIGHT POSSIBILITY OF LOCALIZED FLASH FLOODING. THE
OVERALL WIND THREAT REMAINS LOW DUE TO THE MOIST ATMOSPHERIC
PROFILES.
BY SATURDAY...MODELS INDICATE DRYING WILL START TO WORK INTO
SOUTHEAST CALIFORNIA AND FAR SOUTHWEST ARIZONA VIRTUALLY ELIMINATING
RAIN CHANCES THERE. MAINLY SLIGHT CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE SOUTH-CENTRAL
DESERTS AND HIGHER CHANCES ACROSS THE HIGHER TERRAIN NORTH AND EAST
OF PHOENIX. AS THE DRIER AIR FILTERS INTO THE REGION...TEMPERATURES
WILL BE ON THE RISE...REACHING NEAR OR SLIGHTLY ABOVE SEASONAL
NORMALS SATURDAY INTO EARLY NEXT WEEK. BY SUNDAY...EVEN THE
SOUTH-CENTRAL LOWER DESERTS SHOULD MAINLY BE DRY AS THE DRY FLOW
SLIDES EASTWARD.
ALTHOUGH WE ARE NOT COMPLETELY SOLD ON THE LONG RANGE MODEL
SOLUTIONS FOR THE MIDDLE OF NEXT WEEK...IT DOES LOOK LIKE A FAIRLY
SIGNIFICANT UPPER LOW MAY MAKE IT/S WAY ACROSS THE SOUTHERN PLAINS
INTO NEW MEXICO BY NEXT TUESDAY. IT IS TOO EARLY TO KNOW HOW MUCH
MOISTURE WILL BE AVAILABLE ACROSS THE REGION...BUT IF THIS SOLUTION
PANS OUT...THE MIDDLE OF NEXT WEEK COULD SEE VERY ACTIVE MONSOON
ACTIVITY ACROSS EASTERN ARIZONA AND POSSIBLY INTO THE LOWER DESERTS.
THE OVERALL FLOW DURING THIS TIME WILL LIKELY BE FROM THE NORTHEAST
ACROSS EASTERN ARIZONA AND FROM THE SOUTH ACROSS FAR WESTERN
ARIZONA. A SCENARIO LIKE THIS WOULD LIKELY RESULT IN DRY CONDITIONS
TO THE WEST OF PHOENIX AND AN ACTIVE MONSOON PERIOD ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. THE LONG RANGE TEMPERATURE OUTLOOK
SHOULD BRING NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES ACROSS OUR
WESTERN ZONES AND NEAR TO SLIGHTLY BELOW NORMAL FOR SOUTH-CENTRAL
AND EAST-CENTRAL ARIZONA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ABUNDANT MID/HIGH LEVEL CLOUDS WILL AFFECT CNTRL ARIZONA TERMINALS
THROUGH SATURDAY MORNING. SOME AFTERNOON SCT CU WITH BASES AS LOW AS
9K FT MAY DEVELOP...BUT LARGELY CIGS WILL HAVE NO IMPACT. ISOLD/SCT
TSTMS SHOULD REMAIN SOUTH AND EAST OF THE PHOENIX AREA...AND
ALTHOUGH SOME OUTFLOW COULD CONCEIVABLY REACH THESE
SITES...PROBABILITIES AND CONFIDENCE ARE FAR TOO LOW TO INCLUDE ANY
MENTION AT THIS TIME. LIGHT SFC WINDS SHOULD GENERALLY REMAIN OUT OF
A WESTERLY DIRECTION...THOUGH SOME PERIODS OF MORE VARIABLE
DIRECTIONS CAN BE EXPECTED.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
PRIMARILY ONLY HIGH CLOUDS WILL COVER SOUTHEAST CALIFORNIA TERMINALS
THROUGH SATURDAY MORNING. MOST MODEL GUIDANCE INDICATES NO SHOWERS
OR TSTMS AFFECTING THIS REGION TODAY...SO HAVE NOT INCLUDED ANY
MENTION IN THIS PACKAGE. SFC WINDS WILL REMAIN LIGHT WITH A WEAK
PRESSURE GRADIENT...AND MOSTLY FROM A S/SW DIRECTION...THOUGH
EXTENDED PERIODS OF A LIGHT AND VARIABLE NATURE CAN BE EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A DRYING TREND WILL KEEP STORM CHANCES MAINLY CONFINED TO THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX SUNDAY AND MONDAY. MINIMUM
HUMIDITY VALUES IN THE TEENS WILL PERSIST ACROSS THE LOWER DESERTS
FOR SUNDAY AND MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM
VALUES WILL IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE
WITH ANOTHER INCREASE IN MOISTURE. OVERNIGHT RECOVERY SHOULD BE GOOD
TO EXCELLENT WITH READINGS CLIMBING ABOVE 40 PERCENT MOST NIGHTS.
DAYTIME GUSTY WINDS ARE POSSIBLE EACH DAY...ALONG WITH POSSIBLE
THUNDERSTORM OUTFLOW BOUNDARY WINDS ON SATURDAY AND AGAIN TUESDAY
AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION...MO
FIRE WEATHER...CDEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 PM MST THU JUL 11 2013
.SYNOPSIS...THUNDERSTORM CHANCES WILL GRADUALLY DECREASE FRIDAY
THROUGH SUNDAY. THEREAFTER...ADEQUATE MOISTURE WILL CONTINUE THE
CYCLE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS MONDAY THROUGH
WEDNESDAY. COOLER DAYTIME TEMPERATURES TODAY FOLLOWED BY A WARMING
TREND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...MUCH QUIETER EVENING ACROSS SOUTHEAST ARIZONA WITH
BULK OF SCATTERED STORMS OCCURRING THIS AFTERNOON. NO STORMS ATTM
ACROSS SE ARIZONA...BUT THERE ARE SCATTERED STORMS SOUTH OF THE NEW
MEXICO BOOT. EARLIER RUNS OF THE HRRR MODEL HAD THEM STORMS PUSHING
INTO THE EASTERN ZONES LATER TONIGHT. HOWEVER THE LAST COUPLE OF
RUNS HAS BACKED OFF OF THIS IDEA. IN ANY EVENT...WILL KEEP A CHANCE
OF STORMS ACROSS COCHISE...GRAHAM AND GREENLEE COUNTIES OVERNIGHT
WITH A SLIGHT CHANCE AS FAR WEST AS TUCSON. UPDATED TO FORECAST DUE
OUT SHORTLY. CHECK PREVIOUS DISCUSSION BELOW FOR DETAILS ON FRIDAY
FORECAST AND BEYOND.
POSTED ON OUR WEBSITE...FACEBOOK AND TWEETED 2013 MONSOON RAINFALL
AMOUNTS THROUGH TODAY. SOME AREAS ALREADY IN JULY TOP 10 WETTEST ON
RECORD. CHECK IT OUT.
&&
.PREVIOUS DISCUSSION...
FOR TOMORROW...MOISTURE PROFILE LOOKS LESS PROMISING. NAM SHOWS
DRYING AT ALL LEVELS ESPECIALLY ABOVE 700 MB. THIS MAKES SENSE GIVEN
THE CURRENT WV IMAGERY SHOWING DRY AIR OVER THE GREAT PLAINS WHICH
SHOULD CYCLE INTO ARIZONA BY THIS TIME TOMORROW. THEN AS THE RIDGE
SLIDES EAST...ANY CHANCE OF RECYCLING SOME OF OUR MID LEVEL MOISTURE
LOOKS SLIM. WE WILL NEED TO RELY ON OUR OLD FAITHFUL SOURCES OF
MONSOON MOISTURE...AND GIVEN THE PERSISTENT LOW LEVEL FLOW OUT OF
THE SOUTH TO SOUTHEAST THIS WEEKEND...I DO ANTICIPATE SOME MOISTURE
AVAILABLE FOR AFTERNOON CONVECTION. IT JUST APPEARS THE POTENTIAL
FOR WIDESPREAD HEAVY RAIN DIMINISHES THROUGH THE WEEKEND. THIS
SHOULD ALSO TRANSLATE INTO A WARMING TREND WITH HIGHS RAMPING UP A
FEW DEGREES ABOVE NORMAL BY SUNDAY AND MONDAY.
NOW FOR THE BIG CHANGES FROM YESTERDAY. MODELS WERE SHOWING A LOVELY
INVERTED TROUGH REACHING ARIZONA LATE MONDAY LASTING THROUGH THE
MIDDLE OF NEXT WEEK. TODAY...THE CONSENSUS AMONG THE DETERMINISTIC
AND ENSEMBLE MEAN RUNS OF THE GFS AND ECMWF SHOW AN INTERESTING
EVOLUTION TO THE UPPER FLOW. OUR MAIN MONSOON RIDGE SPLITS INTO TWO
LOBES WITH ONE HIGH OVER THE GREAT LAKES REGION AND THE SECOND HIGH
OVER THE SOUTHWEST U.S.. OUR INVERTED TROUGH THEN TAKES THE PATH OF
LEAST RESISTANCE INTO THE LOWER PRESSURE BETWEEN THE TWO HIGHS. SO
WE END UP WITH AN EASTERLY WAVE...OR INVERTED TROUGH...AT ABOUT 40
DEG NORTH LATITUDE. THAT IS PRETTY FAR NORTH FOR AN EASTERLY MOVING
TROUGH...BUT IT DOES HAPPEN ON OCCASION. AZ WOULD THEN SIT UNDER
NORTHEAST FLOW ALOFT STARTING AROUND TUESDAY. THIS CAN PRODUCE AN
ACTIVE PATTERN WITH ROUTINE CONVECTION AND POSSIBLE FLOODING
CONCERNS IF THE MOISTURE IS PRESENT. THEN...ONCE THE INVERTED TROUGH
REACHES AZ BY THURSDAY...THE IMPROVED INSTABILITY COULD HELP STORMS
LINGER THROUGH OVERNIGHT HOURS.
THE BIG CAVEAT IS THAT THESE SOLUTIONS ARE IN THE EXTENDED RANGES OF
THE CURRENT FORECAST PERIOD SO A LOT CAN CHANGE. BUT CERTAINLY THIS
FEATURE IS WORTH WATCHING FOR THE MID TO END OF NEXT WEEK.
&&
.AVIATION...ANY SHOWERS AND THUNDERSTORMS OVERNIGHT WILL GENERALLY
BE EAST OF KTUS. FOR FRIDAY...EXPECT SCATTERED AFTERNOON
THUNDERSTORMS TO RETURN TO THE AREA. GUSTY AND ERRACTIC WINDS NEAR
STORMS. OTHERWISE SURFACE WINDS DIURNALLY DRIVEN LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY AFTERNOON THROUGH EARLY MORNING
SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A SLIGHT DIMINISHING
TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL PRODUCE
GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF THE
THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. THROUGH FRIDAY...DAYTIME
RELATIVE HUMIDITIES WILL RANGE FROM THE 20S TO 40S WITH GOOD
NIGHTTIME RECOVERIES THROUGH THEN THERE WILL BE A SLIGHT DRYING
TREND THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
326 PM MDT FRI JUL 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 246 PM MDT FRI JUL 12 2013
THUNDERSTORMS DEVELOPED EARLIER TODAY THAN PAST FEW DAYS AND ARE
DEFINITELY MORE NUMEROUS ACROSS WESTERN AREAS BENEATH THE MONSOON
PLUME...AIDED BY SHORTWAVE ENERGY LIFTING NORTHWARD OUT OF NEW
MEXICO. 4KM WRF SEEMS TO HAVE HANDLED THE CONVECTION BETTER THAN
MORNING HRRR RUNS SO FAR. BURN SCARS HAVE BEEN LARGELY MISSED AS OF
20Z...HOWEVER THAT COULD CHANGE BEFORE THE EVENING IS OUT WITH LOTS
OF ACTIVITY IN NORTHERN NM WORKING ITS WAY SLOWLY NORTHWARD. WITH
PRECIP WATERS RUNNING ANYWHERE FROM 112-185 PERCENT OF NORMAL
(HIGHEST VALUES OUT WEST)...THUNDERSTORMS THROUGH THIS EVENING WILL
BE EFFICIENT HEAVY RAINERS...WHICH WILL ELEVATE CONCERNS FOR FLASH
FLOODING ON BURN SCARS. THE WEST FORK COMPLEX IS MOST UNDER THE GUN
FOR THIS...SO WILL CONTINUE WITH THE FLASH FLOOD WATCH. WITH FLOW
ALOFT FROM THE SOUTH SOUTHWEST...MOST THUNDERSTORMS WILL BE TIED TO
THE HIGHER TERRAIN...BUT HRRR SUGGESTS AN ISOLATED SHOWER OR TWO NOT
OUT OF THE QUESTION...ESPECIALLY ALONG THE I-25 CORRIDOR AS OUTFLOWS
COME OFF THE MOUNTAINS. DUE TO THE SLOW MOVEMENT OF THUNDERSTORMS
TODAY...FLASH FLOODING WILL ALSO BE POSSIBLE ON THE BURN SCARS IN
THE EASTERN MOUNTAINS IF A STRONGER STORM WERE TO DEVELOP OVER
THEM.
THUNDERSTORMS WILL GRADUALLY DIMINISH THIS EVENING AS WE LOOSE
HEATING. WE GET TO DO IT ALL OVER AGAIN FOR SATURDAY. SOME SUBTLE
DIFFERENCES WILL BE MORE EASTERLY LOW LEVEL FLOW ACROSS NORTHERN
PORTIONS OF THE SOUTHEAST PLAINS BEHIND A WEAK FRONT WHICH DROPS IN
TONIGHT. DEW POINTS DON`T APPEAR TO BE THAT MUCH DIFFERENT FROM
TODAY...THUS LCLS ARE SIMILAR AS WELL. AND WITH UPPER HIGH CENTER
SHIFTING SOUTH OF THE AREA...STORM MOTIONS MAY ATTAIN A BIT MORE OF
A WESTERLY COMPONENT THAN TODAY WHICH MAY HELP THEM MOVE FARTHER
EAST OFF THE MOUNTAINS AND INTO THE ADJACENT PLAINS OF EL PASO
COUNTY. NAM12 IS ALSO DEVELOPING CONVECTION ACROSS THE SOUTHEAST
PLAINS ALONG THE STALLED FRONTAL BOUNDARY WHICH SETS UP ALONG A LINE
FROM ROUGHLY TRINIDAD TO LA JUNTA TO EADS. CAPES NOT ALL THAT HIGH
AND SHEARS ARE DEFINITELY WEAK...SO NOT EXPECTING THEM TO BE TOO
STRONG. HOWEVER WITH NOT MUCH CHANGE IN PRECIPITABLE WATERS...HEAVY
RAINERS WILL ONCE AGAIN BE THE MAIN THREAT WITH FLASH FLOODING
POSSIBLE ON THE AREA BURN SCARS. DIFFICULT TO PICK OUT ANY
SHORTWAVES EMBEDDED IN THE FLOW TO HELP ENHANCE COVERAGE...BUT WEST
FORK BURN SCAR MAY BE MOST UNDER THE GUN FOR FLASH FLOODING BASED ON
AVAILABLE MOISTURE. WILL LET LATER SHIFTS LOOK AT LATEST
HIGH RES MODELS BEFORE ISSUING ANY MORE FLASH FLOOD WATCHES.
WALDO...BLACK FOREST...AND OTHER BURN SCARS ACROSS THE SOUTHEAST
MOUNTAINS WILL ALSO BE UNDER THE GUN AGAIN...SO THOSE IN AND
NEAR THE BURN SCARS NEED TO MAINTAIN A HEIGHTENED AWARENESS FOR THE
POTENTIAL FOR FLASH FLOODING OVER THE WEEKEND AND ESPECIALLY INTO
SUNDAY (SEE DISCUSSION BELOW). -KT
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 246 PM MDT FRI JUL 12 2013
...HEAVY RAIN POSSIBLE SUNDAY AND INTO MONDAY...
.SUNDAY AND MONDAY...MAIN THREATS ARE POTENTIAL FOR HEAVY RAINS
AND SEE HYDRO DISCUSSION FOR MORE DETAILS.
.TUESDAY THROUGH FRIDAY...MAIN CHALLENGE IS THE AMOUNT OF
MOISTURE WHICH WILL INFLUENCE THE AMOUNT OF AFTERNOON AND EVENING
CONVECTION. THE EC AND GFS SUGGEST DRIER AIR ALOFT WILL ADVECT
INTO THE REGION FROM THE EAST AS THE UPPER LOW MOVES INTO ARIZONA
AND WEAKENS. MAIN DIFFERENCE IS THE AMOUNT OF MOISTURE WHICH
GRADUALLY MOVES NORTHWARD DURING THE LATTER PART OF THE WEEK. EC
IS STRONGER WITH THE RIDGE OVER THE WESTERN US KEEPING THE REGION
DRIER...WHILE THE GFS HAS MORE MOISTURE WITH A WEAKER RIDGE. THE
EXTENDED MODELS HAVE BEEN HAVING TROUBLE WITH THE FINER DETAILS
LATELY. FOLLOWED THE CR EXTENDED PROCEDURE CLOSELY WHICH HAS
GENERALLY SCATTERED CONVECTION OVER THE MOUNTAINS. BELIEVE THE
MOST LIKELY SOLUTION IS TO HAVE ENOUGH MOISTURE FOR CONVECTION
OVER THE MOUNTAINS...WITH MOSTLY LIGHT TO MODERATE RAINFALL
AMOUNTS. --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 246 PM MDT FRI JUL 12 2013
VCTS WILL BE POSSIBLE THROUGH EARLY EVENING AT BOTH KCOS AND KALS.
KPUB COULD SEE SOME ERRATIC WINDS LATER THIS AFTERNOON...BUT IS
LEAST LIKELY TO SEE -TSRA ACTIVITY AS THUNDERSTORMS STAY TIED MAINLY
TO THE HIGHER TERRAIN. LOCALLY HEAVY RAIN WILL BE THE PRIMARY
THREATS. OTHERWISE...VFR CIGS/VIS EXPECTED OUTSIDE OF
THUNDERSTORMS. THUNDERSTORM ACTIVITY SHOULD DIMINISH THIS EVENING
WITH LOSS OF HEATING. WINDS WILL BECOME NORTHERLY AT KCOS AND KPUB
OVERNIGHT AS A WEAK FRONT DROPS IN FROM THE NORTH. WINDS WILL SHIFT
OUT OF THE EAST FOR SATURDAY FOR KCOS AND KPUB. ANOTHER ROUND
OF SCATTERED AFTERNOON THUNDERSTORMS WILL DEVELOP ACROSS THE
MOUNTAINS AND COULD MOVE INTO THE ADJACENT TAF SITES DURING THE
AFTERNOON WITH KCOS AND KALS MOST LIKELY TO SEE -TSRA ACTIVITY. MAIN
THREAT WITH THUNDERSTORMS WILL BE LOCALLY HEAVY RAIN AND ERRATIC
GUSTY WINDS. -KT
&&
.HYDROLOGY...
ISSUED AT 246 PM MDT FRI JUL 12 2013
...HEAVY RAIN POSSIBLE SUNDAY AND MONDAY...
MODELS CONTINUE TO SUGGEST THE THREAT FOR SOME HEAVY RAINFALL
SUNDAY OVER THE INTERSTATE 25 CORRIDOR AND EASTERN MOUNTAINS.
UNUSUAL WEATHER PATTERN DEVELOPING WITH UPPER LOW OVER OHIO MOVING
WESTWARD AND REACHING COLORADO BY MONDAY. BEING AN UNUSUAL WEATHER
PATTERN...HAVE NO EXPERIENCE WITH SIMILAR EVENTS. MODELS CONTINUE TO
MOISTEN THE WESTERN SIDE OF THE UPPER LOW. MODELS ARE ALSO SIMILAR
WITH A DISTURBANCE ON THE LEADING EDGE OF THE UPPER LOW REACHING
EASTERN COLORADO SUNDAY AND SUNDAY EVENING. THERE IS DEEP EASTERLY
FLOW UP TO AT LEAST 700MB SUNDAY WHICH SHOULD MOISTEN THE LOWER
LAYERS. WITH THE MOIST EASTERLY FLOW IN THE LOWER LAYERS...MOIST
AIR ALOFT AND WEAK DISTURBANCE...THE THREAT FOR HEAVY RAINS OVER
THE INTERSTATE 25 CORRIDOR AND EASTERN MOUNTAINS CONTINUE. THE
AMOUNT OF RAIN WILL DEPEND ON THE FINER DETAILS WHICH ARE STILL
EVOLVING. LATEST SIMULATIONS HAVE THE WINDS ALOFT BECOMING MORE
EASTERLY WHICH WOULD TEND TO PROPAGATE STORMS WESTWARD MORE
QUICKLY. IF THE UPPER LEVELS ARE NOT AS MOIST OR SLIGHTLY
WARMER...THEN THERE IS THE POTENTIAL FOR THE ATMOSPHERE TO REMAIN
CAPPED WITH POSSIBLY A LONGER DURATION LIGHT PRECIPITATION EVENT.
GIVEN THE SENSITIVITY OF THE BURN SCARS TO LOCAL DOWNPOURS...HAVE
DECIDED TO INCLUDE MENTION OF HEAVY RAIN IN THE ZONES AND HWO. AS
THE UPPER LOW MOVES TO THE SOUTH ON MONDAY...WARMER AND DRIER AIR
ALOFT WILL TEND TO LIMIT CONVECTION AND REDUCE THE THREAT FOR
HEAVY RAIN. AREA OF HEAVIER RAIN WILL MOVE WESTWARD..POSSIBLY
BEING CENTERED ON THE SOUTHWEST MOUNTAINS...INCLUDING THE WEST
FORK COMPLEX. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ067-068.
&&
$$
SHORT TERM...KT
LONG TERM...PGW
AVIATION...KT
HYDROLOGY...PGW
AREA FORECAST DISCUSSION
NWS MIAMI FL
1005 PM EDT SAT JUL 13 2013
.UPDATE...
SHOWERS AND THUNDERSTORMS THAT PRODUCED HEAVY RAINS ACROSS THE
EAST COAST METRO AREAS THIS AFTERNOON HAVE DECREASED IN COVERAGE
THIS EVENING. MOST OF THE RAINFALL WAS FOCUSED ALONG METRO BROWARD
COUNTY WHERE 5 TO 6 INCHES OF RAIN OCCURRED. LIGHT TO MODERATE
RAIN CONTINUES ACROSS THIS AREA AND COULD PRODUCE UP TO AN
ADDITIONAL INCH OF RAIN. ADJUSTED POP AND QPF TO ADJUST FOR LATEST
TRENDS. UPDATE SENT.
&&
.PREV DISCUSSION... /ISSUED 830 PM EDT SAT JUL 13 2013/
AVIATION...
THUNDERSTORM ACTIVITY HAS CONTINUED TO DIMINISH ALONG THE EAST COAST
THIS EVENING BUT PERIODS OF MVFR OR EVEN BRIEF IFR CEILINGS ARE
STILL POSSIBLE OVER THE NEXT HOUR OR SO BUT MAINLY ACROSS TERMINALS
IN MIAMI DADE (MIA AND TMB). STRONG CONVECTION WILL BE AFFECTING
VICINITY OF APF OVER THE NEXT COUPLE OF HOURS WHERE AGAIN PERIODS OF
MVFR OR EVEN BRIEF IFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE.
WILL HANDLE THAT WITH AMENDMENTS AS NEEDED.
WITH CONDITIONS IMPROVING OVERNIGHT MOSTLY VFR CONDITIONS ARE
EXPECTED TO PREVAIL THROUGH THE REST OF THE FORECAST PERIOD. BUT
BY LATE TOMORROW MORNING OR EARLY AFTERNOON SHOWERS AND
THUNDERSTORMS WILL ONCE AGAIN BE LIKELY. FOR THE MOMENT AM HANDLING
WITH VCTS AT ALL SITES BUT THAT WILL LIKELY NEED TO CHANGE IN THE
NEXT FORECAST AROUND 06Z. AS TODAY, PERIODS OF MVFR AND EVEN BRIEF
PERIODS OF IFR CEILINGS/VIS WILL BE POSSIBLE AGAIN TOMORROW WITH ANY
STORMS AFFECTING A TERMINAL.
WINDS TOMORROW ARE FORECAST TO BE MOSTLY FROM THE SE IN THE 7 TO 12
KT RANGE BUT HIGHLY VARIABLE AROUND THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 227 PM EDT SAT JUL 13 2013/
DISCUSSION...
THE LARGE SCALE CIRCULATION DEPICTS A TROUGH OF LOW PRESSURE OVER THE
EASTERN US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC TO
INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS. AT THIS TIME THE AREA OF HIGH PRESSURE
OVER NORTH AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH
FLORIDA WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD
ON THE SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT
CHANGES IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR
TRAVEL AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC. THE
INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL ARE
FORECAST TO PUSH NORTHWARD EAST OF THE FLORIDA PENINSULA THIS
WEEKEND FORCED BY A HIGH AMPLITUDE TROUGH OF LOW PRESSURE OVER THE
NORTHERN GULF. THE TROUGH OF LOW PRESSURE OVER THE NORTHERN GULF
COULD GENERATE A WEAK LOW INTO NORTH FLORIDA THIS WEEKEND. THIS
SHOULD NOT IMPACT THE WEATHER OVER SOUTH FLORIDA FOR SUNDAY AND
MONDAY AS THE HIGH PRESSURE IN THE ATLANTIC IS INTENSIFYING AND
MOVING WESTWARD AT THE SAME TIME.
THE STEERING WINDS WILL REMAIN FROM THE SOUTH AND SOUTHWEST ON
SATURDAY, TRANSITIONING TO THE SOUTHEAST ON SUNDAY AND TURNING
SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A WEAKNESS IN THE
HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY OVER THE BAHAMA
ISLANDS. THIS WILL BRING A BRIEF PERIOD OF NORTHEASTERLY WINDS ON
MONDAY MORNING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND EASTERN PORTIONS. FOR
SUNDAY SHOWERS AND THUNDERSTORMS WILL PROBABLY DEVELOP OVER THE
INTERIOR BY MID MORNING AND THEN SHIFT TOWARD THE WEST AS THE DAY
PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW BOUNDARIES COULD
STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO AREAS ON SUNDAY.
FOR MONDAY, THE DEVELOPMENT OF A BRIEF PERIOD OF NORTHEASTERLY WINDS
OVER THE ATLANTIC WATERS AND EASTERN COUNTIES COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS AND ENHANCE MOISTURE
CONVERGENCE IN THE WEST COAST DURING THE AFTERNOON HOURS, POSSIBLY
CONCENTRATING THE SHOWER AND THUNDERSTORM ACTIVITY OVER COLLIER
COUNTY. FOR NEXT WEEK, THE MAIN CONCENTRATION OF SHOWERS AND STORMS
IS FOR THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED AFTER MONDAY.
AVIATION...
HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS EMBEDDED WILL CONTINUE TO
IMPACT THE EAST COAST TERMINALS THROUGH THE AFTERNOON/EVENING
PERIODS TODAY...MAINLY FROM FLL TO PBI. REDUCED CIGS/VSBYS IN AND
AROUND THIS ACTIVITY WILL REMAIN THE CONCERN THROUGH THIS TIME. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
CONDITIONS AND GENERALLY INDICATE THIS ACTIVITY REMAINING FOCUSED IN
THE BROWARD/PALM BEACH AREAS THROUGH THIS EVENING BEFORE TRENDING
DOWN OVERNIGHT. WINDS WILL REMAIN ONSHORE AT THE SURFACE (SW GULF
COAST AND SE FOR EAST COAST) WITH A OCCASIONAL MODERATE GUSTS
POSSIBLE THROUGH THE AFTERNOON HOURS. ON SUNDAY...CONDITIONS SHOULD
BEGIN TO TREND BACK TO NORMAL AS THE LOW-LEVEL FLOW SHIFTS BACK
TOWARD THE EAST AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE
AREA. THIS WILL SUPPORT AFTERNOON ACTIVITY SETTING UP INLAND OF THE
EAST COAST TAF SITES AND FARTHER WEST.
MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST
TO SOUTHEAST WIND IS ANTICIPATED THROUGH THE WEEKEND AND INTO THE
MIDDLE OF NEXT WEEK.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT THIS WEEKEND AND ABOVE 48 PERCENT
FOR NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 88 74 88 / 60 60 20 20
FORT LAUDERDALE 72 88 77 88 / 60 60 30 30
MIAMI 71 89 76 88 / 60 60 30 30
NAPLES 75 87 73 91 / 50 70 40 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...52/PS
AREA FORECAST DISCUSSION
NWS MIAMI FL
830 PM EDT SAT JUL 13 2013
.AVIATION...
THUNDERSTORM ACTIVITY HAS CONTINUED TO DIMINISH ALONG THE EAST COAST
THIS EVENING BUT PERIODS OF MVFR OR EVEN BRIEF IFR CEILINGS ARE
STILL POSSIBLE OVER THE NEXT HOUR OR SO BUT MAINLY ACROSS TERMINALS
IN MIAMI DADE (MIA AND TMB). STRONG CONVECTION WILL BE AFFECTING
VICINITY OF APF OVER THE NEXT COUPLE OF HOURS WHERE AGAIN PERIODS OF
MVFR OR EVEN BRIEF IFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE.
WILL HANDLE THAT WITH AMENDMENTS AS NEEDED.
WITH CONDITIONS IMPROVING OVERNIGHT MOSTLY VFR CONDITIONS ARE
EXPECTED TO PREVAIL THROUGH THE REST OF THE FORECAST PERIOD. BUT
BY LATE TOMORROW MORNING OR EARLY AFTERNOON SHOWERS AND
THUNDERSTORMS WILL ONCE AGAIN BE LIKELY. FOR THE MOMENT AM HANDLING
WITH VCTS AT ALL SITES BUT THAT WILL LIKELY NEED TO CHANGE IN THE
NEXT FORECAST AROUND 06Z. AS TODAY, PERIODS OF MVFR AND EVEN BRIEF
PERIODS OF IFR CEILINGS/VIS WILL BE POSSIBLE AGAIN TOMORROW WITH ANY
STORMS AFFECTING A TERMINAL.
WINDS TOMORROW ARE FORECAST TO BE MOSTLY FROM THE SE IN THE 7 TO 12
KT RANGE BUT HIGHLY VARIABLE AROUND THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 227 PM EDT SAT JUL 13 2013/
DISCUSSION...
THE LARGE SCALE CIRCULATION DEPICTS A TROUGH OF LOW PRESSURE OVER THE
EASTERN US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC TO
INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS. AT THIS TIME THE AREA OF HIGH PRESSURE
OVER NORTH AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH
FLORIDA WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD
ON THE SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT
CHANGES IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR
TRAVEL AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC. THE
INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL ARE
FORECAST TO PUSH NORTHWARD EAST OF THE FLORIDA PENINSULA THIS
WEEKEND FORCED BY A HIGH AMPLITUDE TROUGH OF LOW PRESSURE OVER THE
NORTHERN GULF. THE TROUGH OF LOW PRESSURE OVER THE NORTHERN GULF
COULD GENERATE A WEAK LOW INTO NORTH FLORIDA THIS WEEKEND. THIS
SHOULD NOT IMPACT THE WEATHER OVER SOUTH FLORIDA FOR SUNDAY AND
MONDAY AS THE HIGH PRESSURE IN THE ATLANTIC IS INTENSIFYING AND
MOVING WESTWARD AT THE SAME TIME.
THE STEERING WINDS WILL REMAIN FROM THE SOUTH AND SOUTHWEST ON
SATURDAY, TRANSITIONING TO THE SOUTHEAST ON SUNDAY AND TURNING
SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A WEAKNESS IN THE
HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY OVER THE BAHAMA
ISLANDS. THIS WILL BRING A BRIEF PERIOD OF NORTHEASTERLY WINDS ON
MONDAY MORNING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND EASTERN PORTIONS. FOR
SUNDAY SHOWERS AND THUNDERSTORMS WILL PROBABLY DEVELOP OVER THE
INTERIOR BY MID MORNING AND THEN SHIFT TOWARD THE WEST AS THE DAY
PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW BOUNDARIES COULD
STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO AREAS ON SUNDAY.
FOR MONDAY, THE DEVELOPMENT OF A BRIEF PERIOD OF NORTHEASTERLY WINDS
OVER THE ATLANTIC WATERS AND EASTERN COUNTIES COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS AND ENHANCE MOISTURE
CONVERGENCE IN THE WEST COAST DURING THE AFTERNOON HOURS, POSSIBLY
CONCENTRATING THE SHOWER AND THUNDERSTORM ACTIVITY OVER COLLIER
COUNTY. FOR NEXT WEEK, THE MAIN CONCENTRATION OF SHOWERS AND STORMS
IS FOR THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED AFTER MONDAY.
AVIATION...
HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS EMBEDDED WILL CONTINUE TO
IMPACT THE EAST COAST TERMINALS THROUGH THE AFTERNOON/EVENING
PERIODS TODAY...MAINLY FROM FLL TO PBI. REDUCED CIGS/VSBYS IN AND
AROUND THIS ACTIVITY WILL REMAIN THE CONCERN THROUGH THIS TIME. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
CONDITIONS AND GENERALLY INDICATE THIS ACTIVITY REMAINING FOCUSED IN
THE BROWARD/PALM BEACH AREAS THROUGH THIS EVENING BEFORE TRENDING
DOWN OVERNIGHT. WINDS WILL REMAIN ONSHORE AT THE SURFACE (SW GULF
COAST AND SE FOR EAST COAST) WITH A OCCASIONAL MODERATE GUSTS
POSSIBLE THROUGH THE AFTERNOON HOURS. ON SUNDAY...CONDITIONS SHOULD
BEGIN TO TREND BACK TO NORMAL AS THE LOW-LEVEL FLOW SHIFTS BACK
TOWARD THE EAST AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE
AREA. THIS WILL SUPPORT AFTERNOON ACTIVITY SETTING UP INLAND OF THE
EAST COAST TAF SITES AND FARTHER WEST.
MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST
TO SOUTHEAST WIND IS ANTICIPATED THROUGH THE WEEKEND AND INTO THE
MIDDLE OF NEXT WEEK.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT THIS WEEKEND AND ABOVE 48 PERCENT
FOR NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 88 74 88 / 60 60 20 20
FORT LAUDERDALE 72 88 77 88 / 60 60 30 30
MIAMI 71 89 76 88 / 60 60 30 30
NAPLES 75 87 73 91 / 50 70 40 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...52/PS
AREA FORECAST DISCUSSION
NWS MIAMI FL
239 PM EDT FRI JUL 12 2013
.SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THE LATEST WATER LOOP SHOWED AN UPPER LOW CENTERED JUST SOUTH OF THE
LOCAL AREA OVER THE KEYS WITH PLENTY OF MOISTURE SPREADING NORTH TO
ITS EAST OVER THE ADJACENT ATLANTIC WATERS AND BAHAMAS. THE
AFTERNOON SURFACE ANALYSIS SHOWED A TROUGH OF LOW PRESSURE JUST OFF
THE SE FLORIDA COAST ASSOCIATED WITH WHAT IS LEFT OF CHANTAL AND A
WEAK FRONTAL BOUNDARY EXTENDING WSW FROM SC TO MS. THIS SFC TROUGH
NEAR THE AREA COMBINED WITH THE UPPER LOW AND PLENTY OF DEEP LAYER
MOISTURE WILL CONTINUE TO INFLUENCE THE LOCAL WEATHER THROUGH
SATURDAY WITH SCATTERED/NUMEROUS SHOWERS/TSTMS DEVELOPING EACH
DAY.
THE LOCALLY RUN 1.5 KM WRF AND 13Z HRRR MODEL REFLECTIVITIES ARE IN
DECENT AGREEMENT WITH THE LATEST TRENDS THIS AFTERNOON AND CONTINUE
TO INDICATE THE LATE AFTERNOON ACTIVITY BECOMING MORE WIDESPREAD AND
FOCUSED ACROSS THE EASTERN HALF OF THE SRN FL PENINSULA WITH THE
SW LOW/MID-LEVEL FLOW IN PLACE. ONE OF THE MAIN CONCERNS THROUGH
THE REMAINDER OF THE DAY WILL BE THE POTENTIAL FOR LOCALIZED HEAVY
RAINFALL ACROSS THE EAST COAST AND METRO AREAS...WHICH COULD
QUICKLY RESULT IN URBAN FLOODING OVER THE TYPICALLY FLOOD PRONE
AREAS. ALTHOUGH THIS ACTIVITY IS FORECAST TO TREND DOWN THROUGH
THE LATE EVENING HOURS...THE PREVIOUSLY DISCUSSED SYNOPTIC
FEATURES COMBINED WITH A MID-LEVEL VORT MAX LIFTING NORTH ALONG
THE EAST COAST WILL BE ENOUGH TO KEEP THE RAIN CHANCES UP ACROSS
THE ADJACENT MARINE AREAS THROUGH THE OVERNIGHT HOURS...WHICH MAY
INFLUENCE THE IMMEDIATE COASTAL LOCATIONS.
THE PREVIOUSLY DISCUSSED UPPER LOW AND SURFACE TROUGH OFF THE EAST
COAST WILL BEGIN TO LIFT NORTH AND NORTHWEST OF THE LOCAL AREA LATER
TONIGHT THROUGH SATURDAY NIGHT. HOWEVER...THE LATEST NUMERICAL
GUIDANCE DEPICTS DEEP SOUTHERLY FLOW CONTINUING TO ADVECT MOISTURE
NORTHWARD OUT OF THE CARIBBEAN ACROSS THE FLORIDA PENINSULA THROUGH
THIS TIME. MODEL PWAT SOLUTIONS SHOW A PLUME OF 2-2.1" VALUES
STREAMING OVERHEAD...WHICH WILL SUPPORT WELL ABOVE NORMAL RAIN
CHANCES CONTINUING THROUGH THE DAY SATURDAY. THE MAIN IMPACTS AND
CONCERNS WILL BE LOCALIZED FLOODING WHERE ANY ACTIVITY BECOMES
FOCUSED OVER A PERIOD OF TIME. 85/AG
.LONG TERM (SUNDAY-FRIDAY)...
THE WEATHER PATTERN SUNDAY AND BEYOND WILL FEATURE THE ATLANTIC
RIDGE BUILDING BACK IN. A TYPICAL SUMMERTIME PATTERN IS EXPECTED.
THERE IS ONE FEATURE OF NOTE - AN INVERTED TROUGH EAST OF OUR AREA
ALONG ABOUT 55 DEGREES WEST LONGITUDE. THIS FEATURE BROKE OFF FROM
THE MID LATITUDE WESTERLIES AND IS NOW TRAVELING WESTWARD. BOTH
GFS AND ECMWF TRACK THIS TROUGH ACROSS SOUTH FL ON MONDAY, RATHER
AMPLIFIED WITH NE WINDS AHEAD OF IT AND SE WINDS BEHIND IT.
THIS FEATURE COULD ENHANCE SHOWER AND THUNDERSTORM ACTIVITY AS
IT PASSES ON MONDAY.
57/GREGORIA
&&
.AVIATION...
SCATTERED CONVECTION WILL CONTINUE ACROSS THE SOUTH FLORIDA AREA
THROUGH THE AFTERNOON. LATEST HRRR KEEPS THE ACTIVITY CONFINED ALONG
THE INTERIOR AND EAST COASTAL AREAS THROUGH THE EARLY EVENING HOURS.
KEPT VCTS MENTION AT EACH EAST COAST SITE FROM KMIA NORTHWARD. BRIEF
IFR CONDITIONS CAN BE EXPECTED WITHIN ANY TSRA. FLOW WILL BECOME
MORE SOUTHERLY TOMORROW WITH BETTER COVERAGE OF AFTERNOON SHOWERS
AND THUNDERSTORMS EXPECTED.
&&
.MARINE...
A WEAK TROUGH OF LOW PRESSURE AND AN UPPER LOW WILL CONTINUE TO
GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
MARINE AREAS INTO TONIGHT...ESPECIALLY OVER THE ATLANTIC WATERS.
ALTHOUGH WINDS AND SEAS WILL GENERALLY REMAIN LOW THROUGH THE
WEEKEND...CONDITIONS CAN QUICKLY CHANGE IN AND AROUND HEAVY SHOWERS
AND STORMS. LIGHT TO MODERATE EASTERLY WINDS AND SEAS WILL RETURN
SUNDAY AS THIS TROUGH OF LOW PRESSURE LIFTS NORTH OF THE AREA.
ANOTHER TROUGH IS FORECAST TO APPROACH THE FLORIDA PENINSULA THROUGH
THE DAY MONDAY AND MAY LEAD TO HIGHER RAIN CHANCES ONCE AGAIN.
&&
.FIRE WEATHER...
NO CONCERNS AS RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE
CRITICAL LEVELS EACH DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 76 89 / 40 70 40 50
FORT LAUDERDALE 74 87 77 89 / 40 70 40 50
MIAMI 76 88 76 89 / 40 70 40 50
NAPLES 74 89 75 88 / 30 70 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1003 AM EDT FRI JUL 12 2013
.UPDATE...
OUTSIDE OF A FEW MINOR ADJUSTMENTS BASED ON THE LATEST
OBSERVATIONS AND RADAR TRENDS THIS MORNING...THE PREVIOUS FORECAST
PACKAGE REMAINS ON TRACK WITH NO MAJOR UPDATES NECESSARY AT THIS
TIME. THE LATEST WATER LOOP SHOWED AN UPPER LOW SLOWLY DRIFTING
NORTHWARD OVER THE FLORIDA STRAITS TO THE KEYS WITH PLENTY OF
MOISTURE SPREADING NORTH TO ITS EAST OVER THE ADJACENT ATLANTIC
WATERS AND BAHAMAS. THE LATEST SURFACE ANALYSIS A SHOWED A WEAK
TROUGH OF LOW PRESSURE SOUTH AND SOUTHEAST OF THE SRN FLORIDA
PENINSULA ACROSS THE STRAITS AND A WEAK FRONTAL BOUNDARY
EXTENDING WSW FROM SC TO MS. THIS SFC TROUGH NEAR THE AREA
COMBINED WITH THE UPPER LOW WILL CONTINUE TO INFLUENCE THE LOCAL
WEATHER TODAY WITH SCATTERED SHOWERS/TSTMS EXPECTED TO CONTINUE.
THE 12Z MIA SOUNDING SHOWED A VERY MOIST PROFILE WITH 2.03" PW AND
LIGHT SSW FLOW UP TO AROUND THE H4 LEVEL BEFORE SHIFTING TO THE
ENE ALOFT NORTH OF THE UPPER LOW. THE 10Z HRRR MODEL
REFLECTIVITIES LINE ARE IN DECENT AGREEMENT WITH THE LATEST TRENDS AND
INDICATE ACTIVITY INITIATING ALONG THE GULF COAST SEA BREEZE
THROUGH THE EARLY AFTERNOON AND SPREADING ENE TOWARD THE
BROWARD/PALM BEACH COUNTY AREAS THROUGH THE LATE AFTERNOON/EARLY
EVENING HOURS. AS A RESULT...WILL KEEP THE 60 PERCENT RAINFALL
CHANCES IN THE FORECAST ACROSS THE EASTERN HALF OF THE SRN FL
PENINSULA AND UPDATE AS NECESSARY AS CONDITIONS EVOLVE TODAY. 85/AG
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT FRI JUL 12 2013/
AVIATION...
LITTLE CHANGE FROM PREVIOUS FORECAST REASONING. A LIGHT SOUTHWESTERLY
FLOW IS EXPECTED DURING THE MORNING HOURS THEN A DELAYED EAST COAST
SEA BREEZE COULD SET IN AROUND 18Z TO 19Z BUT MAY NOT PENETRATE AS
FAR INLAND TO TERMINAL KTMB. INCREASING DEEPER LAYERED TROPICAL
MOISTURE WILL LEAD TO INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS
FROM LATE MORNING INTO THE AFTERNOON WITH ALL TERMINALS ASSIGNED
VCTS DURING THIS PERIOD. WITH THE OCCURRENCE OF SHOWERS/THUNDERSTORMS
VERY BRIEF PERIODS OF IFR CONDITIONS MAY BE POSSIBLE.
PREV DISCUSSION... /ISSUED 425 AM EDT FRI JUL 12 2013/
HIGHLIGHTS...
* NUMEROUS SHOWERS/TSTORMS EXPECTED TODAY AND SATURDAY WITH LOCALLY
HEAVY RAINS AND GUSTY WINDS POSSIBLE
* LOCALIZED STREET FLOODING POSSIBLE WHERE HEAVIEST STORMS HIT
* WATERSPOUTS POSSIBLE OFF THE SE FL COAST TODAY
DISCUSSION...THE REMNANTS OF CHANTAL WILL MOVE NORTHWARD OFF THE SE
FLORIDA COAST AND ACROSS THE BAHAMAS TODAY. THERE ARE TWO MAIN AREAS
OF CONVECTION THIS MORNING - ONE ASSOCIATED WITH THE LOW LEVEL VORT
AS PER 850 MB VORTICITY CIMMS ANALYSIS, LOCATED BETWEEN CUBA AND
ANDROS ISLAND. THE OTHER AREA OF MORE ROBUST CONVECTION IS
ASSOCIATED WITH A MID LEVEL VORT CENTER OVER THE EASTERN BAHAMAS.
THE SAME THINKING FROM YESTERDAY HOLDS -- NO SIGNIFICANT DIRECT
IMPACTS ARE EXPECTED ACROSS SOUTH FLORIDA. NHC CONTINUES WITH A 30%
CHANCE OF DEVELOPMENT NEXT 48 HR, AND WE OF COURSE CONTINUE TO
MONITOR THIS, BUT THE TIME WINDOW FOR ANY DIRECT LOCAL IMPACTS IS
CLOSING QUICKLY.
THAT BEING SAID, MOISTURE WILL CONTINUE HIGH AROUND THIS FEATURE
TODAY. WE EXPECT DIURNALLY-DRIVEN CONVECTION WITH SHOWERS AND
THUNDERSTORMS BECOMING NUMEROUS ACROSS THE INTERIOR AND THE EAST
COAST METRO AREAS. WE ALREADY HAD DEVELOPMENT ALONG THE MIAMI-DADE
COAST EARLY THIS MORNING. ONE CAVEAT FOR THIS AFTERNOON IS IF THE
REMNANTS BEGIN TO ORGANIZE, THEN ACTIVITY COULD ACTUALLY LESSEN DUE
TO SUBSIDENCE ON THE WESTERN PERIPHERY OF THE FEATURE. HOWEVER, WE
BELIEVE IN THE WETTER SCENARIO, SO KEPT LIKELY POPS FOR THE INTERIOR
AND EAST COAST AND CHANCE POPS GULF COAST.
LOCALLY HEAVY RAINFALL IS A POSSIBILITY TODAY. IN EXCESS OF 3 INCHES
IS POSSIBLE IN ISOLATED LOCALES WHICH WOULD LEAD TO THE POTENTIAL
FOR STREET FLOODING AND FLOODING OF POORLY DRAINED LOCALES. GUSTY
WINDS WILL BE POSSIBLE IN THE STRONGER THUNDERSTORMS AS WELL.
WATERSPOUTS ARE POSSIBLE OFF THE SOUTHEAST FLORIDA COAST TODAY DUE
TO A MOIST ENVIRONMENT WITH A LIGHT WIND FLOW AND SLIGHTLY
FAVORABLE WIND TURNING WITH HEIGHT.
THE COVERAGE OF SHOWERS AND THUNDERSTORMS WILL LESSEN TONIGHT, BUT
KEPT POPS IN AS MOISTURE WILL BE HIGH ALONG WITH SOME CONVERGENCE
NOTED IN THE LOW LEVEL WIND FIELDS. THEN ANOTHER STORMY DAY IS
EXPECTED ON SATURDAY. GFS SHOWS A MOIST SURGE SPREADING ACROSS THE
AREA IN THE MORNING, MOVING NW ACROSS SOUTH FL IN THE AFTERNOON ON
AN INCREASING S-SE WIND. HOWEVER, MORE ACTIVITY COULD DEVELOP AT ANY
TIME SATURDAY GIVEN THE MOIST AND UNSTABLE ATMOSPHERE EXPECTED.
DECIDED TO INCREASE POPS IN LINE WITH THE NEW GFS MOS NUMBERS.
AGAIN, LOCALLY HEAVY RAINFALL IS POSSIBLE ON SATURDAY.
THE WEATHER PATTERN SUNDAY AND BEYOND WILL FEATURE THE ATLANTIC
RIDGE BUILDING BACK IN. A TYPICAL SUMMERTIME PATTERN IS EXPECTED.
THERE IS ONE FEATURE OF NOTE - AN INVERTED TROUGH EAST OF OUR AREA
ALONG ABOUT 55 DEGREES WEST LONGITUDE. THIS FEATURE BROKE OFF FROM
THE MID LATITUDE WESTERLIES AND IS NOW TRAVELING WESTWARD. BOTH
GFS AND ECMWF TRACK THIS TROUGH ACROSS SOUTH FL ON MONDAY, RATHER
AMPLIFIED WITH NE WINDS AHEAD OF IT AND SE WINDS BEHIND IT.
THIS FEATURE COULD ENHANCE SHOWER AND THUNDERSTORM ACTIVITY AS
IT PASSES ON MONDAY.
MARINE...LIGHT WINDS AND SEAS PREVAIL. THE REMNANTS OF CHANTAL
WILL MOVE NORTH ACROSS THE LOCAL WATERS AND THE BAHAMAS TODAY. NHC
GIVES A 30% CHANCE OF RE-DEVELOPMENT OVER THE NEXT 48 HOURS. EVEN
IF THE REMNANTS BEGIN TO RE-DEVELOP TODAY, HIGHER WINDS WOULD BE
EXPECTED TO BE DISPLACED TO THE EAST OF THE CENTER AND OVER THE
BAHAMAS. SO THE FORECAST REFLECTS LIGHT WIND CONDITIONS. HOWEVER,
WINDS COULD BE GUSTY IN A FEW SQUALLS, ESPECIALLY OVER THE
OFFSHORE ATLANTIC WATERS THIS AFTERNOON-EVENING. PREVAILING WINDS
WILL BE OUT OF THE SOUTHERLY DIRECTION THROUGH TOMORROW THEN
BECOMING E-SE SUNDAY AND BEYOND, WITH THE EXCEPTION OF NORTHEAST
WINDS BRIEFLY ON SUN NIGHT INTO MONDAY AHEAD OF THE PASSAGE OF AN
INVERTED SURFACE TROUGH THEN. THIS TROUGH COULD BRING ENHANCED
SHOWER AND THUNDERSTORM ACTIVITY AND POSSIBLY SOMEWHAT HIGHER
WINDS.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 76 89 75 / 60 40 70 40
FORT LAUDERDALE 89 79 89 77 / 60 40 70 40
MIAMI 89 77 90 77 / 60 40 70 40
NAPLES 87 75 88 75 / 50 30 70 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
349 AM EDT Fri Jul 12 2013
.NEAR TERM [Today]...
An unseasonably deep trough at upper levels is once again digging
southward over the eastern half of the U.S., and will stretch from
the Great Lakes to the northern Gulf of Mexico by this afternoon.
Just ahead of this feature, high PWAT values (above 2") are being
drawn into our region from the Gulf. In addition, a stationary
front near our CWA will provide enough forcing to enhance
precipitation chances through the period.
This front is currently located near the northern edge of our CWA,
and has led to the development of some showers in our SW Georgia
counties, which should continue throughout the overnight hours.
Also, scattered showers and thunderstorms will continue to develop
around coastal regions of the Big Bend and our marine zones. With
daytime heating and as the front sags southward into our region
later today, showers and thunderstorms will increase in coverage. CAM
models and the HRRR both show convection developing by the late
morning hours in the Big Bend region and into south central
Georgia, and then spreading to other parts of the CWA later in the
afternoon. Reflected this pattern within the high temperatures,
showing low 90s in our NW counties tapering to mid-upper 80s in
our SE counties, where there is a higher chance of precipitation.
&&
.SHORT TERM [Tonight Through Sunday]...
There is good agreement among the latest NWP guidance in taking the
aforementioned mid-upper level low pressure system from eastern KY
tonight, to OK by Sunday night. As a deep layer subtropical ridge
fills in westward behind this low, moist southeast flow will develop
across our forecast area. Although the Precip Water values are
likely to continue above climatology through the weekend, the best
Q-G forcing is expected to be on Saturday, which is when we forecast
our highest PoP (50-70%). With such a moisture-rich environment,
convection could develop almost anytime on Saturday. On Sunday the
forcing for convection will have to come from mesoscale features
(sea breeze and outflow boundary interactions), so we expect more of
a diurnal cycle to the rain, along with a slightly low PoP (40-50%).
High temperatures will be a few degrees below climo, especially
Saturday.
.LONG TERM [Sunday Night through Thursday]...
The long wave pattern will be in retrogression through much of this
period. An upper low will track from the Midwest to the Central or
Southern Plains (depending on the model you pick) as a ridge pushes
in from the Atlantic. Beneath this ridge, a TUTT will track west
across FL Monday night through Wednesday. At the surface, a front
will lift north across the region on Sunday with the subtropical
"Bermuda" ridge axis mainly north of the area after that. That will
put the area in an easterly flow regime at lower levels. Typical mid
range PoPs are expected through the period with development largely
driven by land and sea breeze circulations. Max temps will be a
couple of degrees below normal with mins close to normal.
&&
.Aviation [Through 06Z Saturday]...
Due to the stationary front stalled just north of our region, widely
scattered areas of showers and possibly a thunderstorm will persist
through the overnight hours in some parts of our region, especially
SW Georgia. VFR conditions are expected at most terminals for the
rest of the evening, although IFR or LIFR conditions are
possible where any low ceilings and fog occur. Ceilings and
visibilities will likely lower in the early morning hours at all
terminals due to the moist conditions and light winds, but ample
cloud cover will likely prevent the formation of widespread fog.
Scattered showers and thunderstorms could increase in coverage
during the late morning hours near TLH and VLD, and will be
possible at all terminals in the afternoon and early evening. IFR
conditions will likely occur in any thunderstorms, but elsewhere
VFR conditions should persist.
&&
.MARINE...
The 00 UTC NAM, and to a lesser extent the GFS, forecast a fairly
well-defined cyclonic circulation to develop in our coastal waters
tonight and Saturday. The ECMWF and SREF mean wind fields have a
much more subtle wind shift associated with a trough, which is the
solution preferred for this forecast cycle. This will keep our winds
and seas below exercise caution levels. If the NAM or GFS were to
verify, however, our wind & seas forecast would be too low. However,
these models (especially the NAM) have a tendency to wind up low
pressure systems too much when there is warm water.
&&
.FIRE WEATHER...
With moist southerly flow to continue through the weekend, no fire
weather concerns are expected. While some drier air is anticipated
to return by Tuesday, RH values should still remain above critical
thresholds.
&&
.HYDROLOGY...
All river points that have been in flood continue to recede, albeit
a little slowly on the lower Choctawhatchee, where Caryville and
Bruce will remain at flood stage for some time. Routed flows from
the Withlacoochee and Alapaha Rivers are progressing downstream and
are now beginning to initiate rises in the lower portions of these
rivers and into the Middle Suwannee. There is considerable capacity
in the Suwannee Basin, so baring significant rainfall, flooding is
not anticipated along the Middle Suwannee, though flows may approach
action stage by the middle of next week at Ellaville and Dowling
Park. It is helpful that routed flows from the Upper Suwannee remain
relatively low, as the bulk of the expected rise on the Middle
Suwannee is occurring from the Withlacoochee and Alapaha Rivers.
The rainfall over this weekend is expected to average aerially
around 2 to 3 inches, with isolated heavier totals possible. This
certainly does not look to be like the significant flooding
rainfall we saw last week, and as a result, widespread flooding is
not anticipated. However, given the wet soil conditions across much
of North Florida and Southern Georgia, a couple of inches of rain in
a short amount of time could easily generate localized flooding,
especially in an urban environment. Expected rainfall could keep
rivers currently in flood at those levels well into next week (like
the Choctawhatchee) and could result in basins like the Ochlockonee
or Chipola nearing flood stage depending on the location of the
heaviest rains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 87 71 88 71 90 / 70 40 60 40 50
Panama City 87 75 85 73 87 / 70 40 50 30 40
Dothan 90 72 88 72 89 / 50 30 50 30 40
Albany 89 71 87 72 90 / 60 30 60 30 50
Valdosta 89 71 90 71 94 / 70 50 70 40 50
Cross City 86 72 88 71 90 / 70 50 70 40 60
Apalachicola 86 74 84 74 87 / 70 50 60 30 50
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Godsey/Lahr
SHORT TERM...Fournier
LONG TERM...Wool
AVIATION...GodseyLahr
MARINE...Fournier
FIRE WEATHER...Godsey/Lahr
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS MIAMI FL
203 AM EDT FRI JUL 12 2013
.AVIATION...
DURING THE EARLY MORNING HOURS...ALL EAST COAST SITES ASSIGNED
VCSH AS SHOWERS CONTINUE TO FORM ACROSS THE NEAR SHORE ATLANTIC
WATERS. TERMINALS KTMB...KMIA AND KOPF MAY EXPERIENCE PASSING
SHOWERS OVER THE NEXT COUPLE OF HOURS WITH BRIEF SUB-VFR
CONDITIONS POSSIBLE...WILL AMEND IF NEEDED BUT PREVAILING VFR
EXPECTED. TERMINAL KAPF EXPECTED TO MAINTAIN VFR THROUGH EARLY MORNING
HOURS. BY MID-MORNING THROUGH THE AFTERNOON...THERE IS A LOT OF
UNCERTAINTY IN THE FORECAST...INCLUDING THE SURFACE WIND FORECAST
AS THE REMNANTS OF CHANTAL CONTINUES TO MOVE NORTH OF THE CUBAN
COAST TOWARDS THE CENTRAL BAHAMAS. AS THIS FEATURE MOVES NORTHWARD
INTO THE NORTHWEST BAHAMAS LATER TODAY...TROPICAL MOISTURE AND
POTENTIAL FOR CONVECTION IS EXPECTED BY THE LATE MORNING INTO THE
AFTERNOON. ALL EAST COAST TERMINALS ASSIGNED VCTS BY 15Z. FOR THE
WIND FORECAST...AROUND 13Z TO 15Z TIME FRAME A LIGHT SOUTHERLY TO
SOUTHWESTERLY FLOW IS FORECAST ACROSS THE REGION...INCLUDING THE
EAST COAST TERMINALS. AROUND 19Z AN EAST COAST SEA BREEZE COULD
TRY TO DEVELOP WHICH WOULD GIVE MOST OF THE EAST COAST TERMINALS A
SSE WIND DIRECTION AROUND 8 KNOTS. BUT NEED TO STRESS THE
UNCERTAINTIES. THE MOST ACTIVE AREAS OF CONVECTION IS EXPECTED TO
BE ACROSS THE ATLANTIC WATERS AND THE EASTERN HALF OF THE
PENINSULA WITH NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
EXPECTED WITH BRIEF PERIODS OF IFR CONDITIONS POSSIBLE WITH
SHOWERS/THUNDERSTORMS.
60
&&
.PREV DISCUSSION... /ISSUED 947 PM EDT THU JUL 11 2013/
UPDATE...
SLIGHT CHANGES WERE DONE TO THE FIRST PERIOD OF THE FORECAST
PACKAGE TO MATCH WITH THIS EVENING`S WEATHER PATTERN. LATEST MODEL
GUIDANCE CONTINUES TO SHOW THE REMNANTS OF CHANTAL REMAINING
OFFSHORE ACROSS THE ATLANTIC OVERNIGHT...WHICH COINCIDES WITH
PREVIOUS MODELS RUNS. 00Z SOUNDING DEPICTING A LIGHT EASTERLY FLOW
AT LOW LEVELS...WHICH COULD HELP BRINGING A FEW SHOWERS THROUGH
THE NIGHT ACROSS THE PENINSULA. CURRENT FORECAST SHOWING EXACTLY
THIS TREND...THEREFORE NO CHANGES WERE NEEDED.
PREV DISCUSSION... /ISSUED 801 PM EDT THU JUL 11 2013/
AVIATION...
THE WEATHER SHOULD REMAIN DRY TONIGHT OVER ALL OF THE TAF SITES
ACROSS SOUTH FLORIDA ALONG WITH LIGHT AND VARIABLE WINDS. THE
WINDS WILL THEN BECOME SOUTHWEST ON FRIDAY AT 5 TO 10 MPH IN THE
MORNING WITH A SLIGHT CHANCE OF SHOWERS. THE EAST COAST SEA BREEZE
SHOULD DEVELOP LATE IN THE DAY AND PUSH INLAND TO ABOUT THE KFXE
AND KTMB TAF SITES BETWEEN 19Z AND 20Z. SO WILL MAKE THE WINDS BE
BETWEEN 170 AND 190 ALONG THE EAST COAST TAF SITES BETWEEN 19Z AND
20Z ON FRIDAY. THERE WILL ALSO BE THE CHANCE OF THUNDERSTORMS
ALONG THE EAST COAST TAF SITES AFTER 19Z. SO HAVE ADDED VCTS TO
THE EAST COAST TAF SITES AFTER 19Z ON FRIDAY. THE CEILING AND VIS
SHOULD REMAIN IN THE VFR CONDITIONS AT ALL OF THE TAF SITES
TONIGHT INTO FRIDAY.
AVIATION..54/BNB
PREV DISCUSSION... /ISSUED 245 PM EDT THU JUL 11 2013/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL LOCATED OVER
EASTERN CUBA AND THE BAHAMAS EAST OF AN UPPER LOW CENTERED ACROSS
THE FLORIDA STRAITS. THE LATEST VISIBLE SATELLITE IMAGERY SHOWED
PLENTY OF CONVECTION CONTINUING TO FLARE BETWEEN JAMAICA AND EASTERN
CUBA EARLY THIS AFTERNOON NEAR A REMNANT TROUGH OF LOW PRESSURE. THE
12Z GFS RUN NOW INDICATES A WEAK SFC LOW DEVELOPING AND LIFTING
NORTH FROM THIS GENERAL AREA OVER THE GULF STREAM JUST EAST OF THE
FLORIDA PENINSULA TONIGHT THROUGH THE DAY FRIDAY WITH THE BULK OF
THE MOISTURE/RAINFALL PROJECTED TO REMAIN TO ITS EAST OVER THE
BAHAMAS. ALTHOUGH CONFIDENCE REMAINS LOW...REGENERATION IS CERTAINLY
NOT OUT OF QUESTION AND ALL INTERESTS ARE ENCOURAGED TO MONITOR THE
LATEST FORECAST AS UPDATES MAY BECOME NECESSARY OVER THE UPCOMING 24
HRS. REGARDLESS OF ANY FURTHER DEVELOPMENT...DAYTIME HEATING
COMBINED WITH THE DEEP LAYER FLOW SHIFTING TO THE WSW WILL FAVOR
CONVECTION INITIATING AND SETTING UP ACROSS THE EAST COAST METRO AND
COASTAL LOCATIONS THROUGH THE AFTERNOON/EVENING PERIODS...ESPECIALLY
ACROSS BROWARD AND PALM BEACH COUNTIES. ON SATURDAY...THE SFC LOW IS
FORECAST TO CONTINUE NORTH THEN NORTHWEST AND ASHORE SOMEWHERE ALONG
THE SC/GA COAST SATURDAY NIGHT. THE GFS PWAT SOLUTIONS INDICATE
VALUES INCREASING TO AROUND THE 2" MARK THROUGH THIS TIME SATURDAY
ACROSS SOUTH FLORIDA. THIS COMBINED WITH THE DEEP SOUTHWEST FLOW
WILL KEEP THE BEST RAIN CHANCES FOCUSED OVER THE EASTERN HALF OF THE
PENINSULA. ALTHOUGH A FEW STRONG STORMS WITH GUSTY WINDS UP TO 40-50
MPH WILL CERTAINLY REMAIN POSSIBLE EACH AFTERNOON...THE MAIN CONCERN
WILL BE THE POTENTIAL FOR LOCALIZED HEAVY RAIN AND URBAN FLOODING
OVER THE HEAVILY POPULATED EAST COAST/METRO AREAS EACH DAY.
LONG TERM (SUNDAY-THURSDAY)...
THE ATLANTIC RIDGE WILL BEGIN TO BUILD IN NORTH OF THE AREA
SUNDAY, WITH STEERING FLOW TURNING MORE EASTERLY. AN EASTERLY
WIND FLOW IS THEN EXPECTED TO PREVAIL NEXT WEEK. BOTH GFS/ECMWF
SHOW AN INVERTED LOW-MID LEVEL TROUGH MOVING ACROSS FLORIDA DURING
THE EARLY-MIDDLE PART OF NEXT WEEK. THIS COULD ENHANCE SHOWER AND
THUNDERSTORM ACTIVITY SOMEWHAT, BUT FOR NOW FOLLOWED GFS MOS WITH
ONLY CHANCE POPS THROUGH THE LONG TERM PERIOD.
57/GREGORIA
AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO FIRE ACROSS MAINLY
THE INTERIOR THIS AFTERNOON FUELED BY SEA BREEZES FROM BOTH THE
ATLANTIC AND GULF. LATEST HRRR AND LOCAL HIGH RESOLUTION MODELS KEEP
THE VAST MAJORITY OF THE ACTIVITY ACROSS INLAND AREAS AND AWAY FROM
THE TAF SITES. DID KEEP VCSH IN AT ALL SITES THROUGH THE AFTERNOON
AND EARLY EVENING. COULD NOT RULE OUT AN ISOLATED TSRA AFFECTING A
TAF SITE BUT NOT CONFIDENT ENOUGH TO CARRY MENTION IN TAFS ATTM.
MARINE...
A SURFACE TROUGH OF LOW PRESSURE WILL LIFT NORTH OVER THE ATLANTIC
WATERS THROUGH THE DAY FRIDAY WITH LIGHT TO MODERATE SOUTH AND
SOUTHWEST FLOW FILLING IN ACROSS THE MARINE AREAS IN ITS WAKE FRIDAY
NIGHT INTO THE WEEKEND. SCATTERED SHOWERS AND STORMS ASSOCIATED WITH
THIS FEATURE...ESPECIALLY ALONG THE EAST COAST EACH AFTERNOON AND
EVENING...COULD LEAD TO PERIODS WITH REDUCED VISIBILITIES...GUSTY
WINDS AND LOCALLY CHOPPIER CONDITIONS IN AND AROUND THE HEAVIER
ACTIVITY.
FIRE WEATHER...
NO CONCERNS AS RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE
CRITICAL LEVELS EACH DAY. THE FLOW WILL SHIFT TO THE SOUTHWEST
FRIDAY THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 75 88 75 / 60 30 60 30
FORT LAUDERDALE 89 78 89 77 / 60 30 60 30
MIAMI 89 77 88 78 / 60 30 60 30
NAPLES 87 74 89 74 / 30 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
128 AM EDT FRI JUL 12 2013
.PREV DISCUSSION... /ISSUED 940 PM EDT THU JUL 11 2013/
UPDATE...
MCV CONTINUES TO ROTATE SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE
SOUTHERN TIER OF THE CWA THIS EVENING. CONVECTION SHOULD GRADUALLY
PERTAIN TO THE SOUTHEASTERN PORTION OF THE AREA INTO MORNING...WHILE
THE FRONT PUSHES INTO NORTH GEORGIA. THIS FRONT HAS BEEN TRIGGERING
SOME ISOLATED THUNDERSTORMS AND SHOWERS...THOUGH NOT AS WIDESPREAD
AS IN THE SOUTH. LOCAL WRF AND HRRR SOLUTIONS SUGGEST A BAND OF
CONVECTION MAY DEVELOP AFTER MIDNIGHT FROM THE ATHENS TO ATLANTA
AREA...THOUGH CONFIDENCE IS NOT HIGH IN THIS PLAYING OUT AT THE
MOMENT. THERE IS AN INSTABILITY AXIS NEAR THIS AREA WHICH COULD
SERVE TO FOCUS THE DEVELOPMENT BUT WILL CONTINUE TO WATCH TRENDS.
ALL CONSIDERED...HAVE KEPT LIKELY POPS SOUTHEAST AND CHANCE POPS
ELSEWHERE TONIGHT. HAVE ALSO KEPT CURRENT FLASH FLOOD WATCH SET TO
EXPIRE AT 04Z FOR NORTH GA AND 06Z SOUTH. OTHERWISE MADE ONLY
MINOR TWEAKS TO TEMP...DEWPT...AND SKY TRENDS. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 818 PM EDT THU JUL 11 2013/
PREV DISCUSSION... /ISSUED 353 PM EDT THU JUL 11 2013/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING TO POP ACROSS THE AREA.
MAIN FRONTAL BOUNDARY IS STILL ACROSS TN BUT IT IS MOVING SLOWLY
SOUTH. THIS FRONT SHOULD MOVE INTO NW GA WITHIN THE NEXT FEW
HOURS. THESE SHOWERS AND THUNDERSTORMS ARE STAYING FAIRLY WEAK AND
NOT MOVING VERY MUCH...SO WILL KEEP AN EYE OUT FOR ANY FLOODING
CONCERNS. THERE IS ALSO LESS INSTABILITY ACROSS THE AREA FOR THESE
STORMS TO WORK WITH TODAY SO THEY SHOULD STAY BELOW SEVERE
CRITERIA. THERE MAY BE A STORM OR TWO THAT GETS CLOSE TO SEVERE
NEAR 00Z WHEN THE INSTABILITIES PEAK...SO WILL HAVE TO CONTINUE TO
MONITOR THIS AS WELL. AS THE FRONT MOVES SOUTH IT WILL WILL USHER
IN SOME DRIER AIR AND SHOULD HELP TO KEEP PRECIPITATION DOWN TO A
MINIMUM ESPECIALLY ACROSS NORTH GA FRIDAY. THIS FRONT WILL ALSO
FINALLY PUSH THE MAIN MOISTURE PLUME THAT HAS BEEN OVER THE AREA
FOR THE PAST FEW WEEKS EAST OF THE STATE. THIS DRIER AIR WILL BE
SHORT LIVED AS THE MOISTURE BEGINS TO RETROGRADE WESTWARD SAT
MORNING.
01
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED PERIODS AS LONG RANGE MODELS
CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH A FRONTAL BOUNDARY
LINGERING ACROSS CENTRAL GA ON SATURDAY... THEN PUSHING NORTH AND
SPREADING DEEPER MOISTURE BACK ACROSS NORTH GA ON SUNDAY. AS A
RESULT... EXPECT DECREASED STORM COVERAGE/THREAT ACROSS MUCH OF
NORTH GA ON SATURDAY... WITH SCATTERED AFTERNOON AND EVENING
STORMS STILL LIKELY ACROSS CENTRAL GA NEARER THE FRONT. BUT THIS
CONVECTIVE BREAK ACROSS NORTH GA WILL BE SHORT-LIVED AS RETURNING
DEEP LAYER MOISTURE BEHIND THE ADVANCING WARM-FRONT WILL ALSO
RETURN THE STORM AND POTENTIAL LOCALLY HEAVY RAIN THREAT BACK TO
NORTH GA BY SUNDAY AFTERNOON. THE ECMWF AND GFS SHOW AMAZING
AGREEMENT WITH A LARGE UPPER RIDGING SETTLING OVER THE OHIO VALLEY
REGION BY MONDAY AND HELPING TO FINALLY SHUNT THE DEEPER MOISTURE
AND GREATER STORM THREAT SOUTHWARD INTO SOUTH GA FOR MON-THU.
HOWEVER... STILL EXPECT SUFFICIENT LOW LEVEL MOISTURE AND DAYTIME
INSTABILITIES TO SUPPORT LOW SCATTERED COVERAGE OF AFTERNOON AND
EVENING STORMS EACH DAY. /39
PREV LONG TERM DISCUSSION... /ISSUED 409 AM EDT THU JUL 11 2013/
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
EXTENDED BEGINS WITH CLOSED UPPER LOW VICINITY OF OHIO VALLEY WITH
SOME DRIER AIR ACROSS NORTH GA. GFS/ECMWF DIFFER IN GENERAL
LOCATION OF THE UPPER LOW...BUT BOTH RETROGRADE IT WESTWARD DURING
THE PERIOD. WITH THE UPPER RIDGE LOCATED OFF THE MID ATLANTIC
COAST...THE CWA REMAINS IN AN EASTERLY FLOW OF MOISTURE FROM THE
ATLANTIC. THIS WILL KEEP US IN A PATTERN OF SHOWERS AND
THUNDERSTORMS EACH DAY AND HAVE KEPT MOST POPS IN THE CHANCE
CATEGORY. BY THE END OF THE PERIOD LOOKS LIKE THE UPPER RIDGE
BEGINS TO BUILD BACK OVER THE SOUTHEAST...SO THE PATTERN MAY
BECOME MORE DIURNAL. TWEAKED MAX TEMPERATURES DOWN A BIT MOST DAYS
DUE TO EASTERLY FLOW AND EXPECTED POPS.
HYDROLOGY...
AS BEEN THE CASE THE PAST SEVERAL DAYS...BASIN-AVERAGE QPF VALUES
ARE NOT PARTICULARLY IMPRESSIVE /BETWEEN 0.5-1 INCH NORTH AND
1-1.5 INCHES SOUTH/...BUT AGAIN THESE ARE BASIN-AVERAGE AND OF
COURSE SOME AREAS WILL GET QUITE A BIT MORE. PW VALUES ARE STILL
RANGING FROM 1.6 TO 2.0 THROUGH 12Z FRI. AS THE FRONT MOVES INTO
THE AREA FORECASTED PW`S DO COME DOWN A BIT FOR FRIDAY. SOME 6-HR
FLASH FLOOD GUIDANCE VALUES ESPECIALLY IN NORTHWEST GEORGIA ARE
LESS THAN AN INCH. SO WITH THAT...WILL KEEP THE FLASH FLOOD WATCH
THROUGH 08Z FRI. WILL ALSO CONTINUE TO KEEP OUR EXTREME SOUTHERN
COUNTIES OUT OF THE WATCH AS THEY CAN HANDLE A BIT MORE PRECIP
THAN AREAS NORTH.
&&
.AVIATION...
06Z UPDATE...
MAIN CONCERN SEEMS TO BE POTENTIAL FOR IFR-MVFR CEILINGS TO
DEVELOP THIS MORNING. POTENTIAL IS THERE BUT OVERALL CONFIDENCE IS
LOW TO MEDIUM. SOME MVFR VSBYS ALSO CAN BE EXPECTED. CONDITIONS
EXPECTED TO IMPROVE DURING THE MORNING TO VFR. CONVECTION OVER NNW
CWA EXPECTED TO DIMINISH NEXT COUPLE OF HOURS AND NOT AFFECT THE
TAFS. BEST POTENTIAL FOR CONVECTION DURING THE DAY LOOKS TO BE
OVER CENTRAL GA WITH THE BEST CHANCES AT CSG/MCN. SURFACE WINDS
LIGHT AND VARIABLE OR CALM TENDING TO BECOMING ENE DURING THE DAY.
//ATL CONFIDENCE...06Z UPDATE...
LOW CONFIDENCE ON MORNING CIGS AND IMPACTS OF ANY CONVECTION TODAY.
MEDIUM CONFIDENCE ON WIND SHIFT TO ENE.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 84 70 / 40 30 40 40
ATLANTA 87 70 84 71 / 30 20 30 40
BLAIRSVILLE 83 64 80 66 / 20 20 20 30
CARTERSVILLE 87 68 86 70 / 20 20 20 30
COLUMBUS 89 72 88 72 / 40 30 40 40
GAINESVILLE 85 70 81 69 / 30 20 30 40
MACON 87 71 86 72 / 60 40 50 50
ROME 87 67 88 69 / 10 10 20 30
PEACHTREE CITY 87 68 84 69 / 30 20 30 40
VIDALIA 85 71 87 73 / 70 40 50 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 4 AM EDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BALDWIN...BIBB...BUTTS...CHATTAHOOCHEE...
CLARKE...CLAYTON...COWETA...CRAWFORD...FAYETTE...GLASCOCK...
GREENE...HANCOCK...HARRIS...HEARD...HENRY...HOUSTON...JASPER...
JEFFERSON...JONES...LAMAR...MACON...MARION...MERIWETHER...
MONROE...MORGAN...MUSCOGEE...NEWTON...OCONEE...OGLETHORPE...
PEACH...PIKE...PUTNAM...ROCKDALE...SCHLEY...SPALDING...TALBOT...
TALIAFERRO...TAYLOR...TROUP...TWIGGS...UPSON...WALTON...WARREN...
WASHINGTON...WILKES...WILKINSON.
&&
$$
SHORT TERM...BDL
LONG TERM....41
AVIATION...BDL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1001 PM CDT SAT JUL 13 2013
.DISCUSSION...
903 PM CDT
CURRENT GRIDS/FORECAST IN GOOD SHAPE. MADE MINOR TWEAKS TO
TEMPS...DEW POINTS AND SKY GRIDS TO FIT CURRENT TRENDS. A FEW
PASSING CLOUDS FAR SOUTHERN PART OF FORECAST AREA ASSOCIATED WITH
WESTWARD MOVING UPPER LOW...OTHERWISE CLEAR SKIES EXPECTED THROUGH
THE OVERNIGHT. WITH LIGHT WINDS...SLOWLY INCREASING DEW POINTS AND
STAGNANT AIR MASS...SOME LIGHT HAZE CAN BE EXPECTED AROUND
SUNRISE...AWAY FROM THE CITY HEAT ISLAND...BUT NOT SIGNIFICANT
ENOUGH TO MENTION IN FORECAST AT THIS TIME.
ALLSOPP
//PREV DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* NONE
IZZI
//DISCUSSION...UPDATED 00Z...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LAKE BREEZE WILL
DEVELOP AND MOVE THRU THE CHICAGO TERMINALS AGAIN SUNDAY AFTERNOON
WITH WINDS TURNING EAST AND PICKING UP TO AROUND 10KT WITH OCNL
GUSTS TO 15KT IN THE AFTERNOON. SURFACE MOISTURE HAS BEEN SLOW TO
INCREASE...SO THINK ANY HAZE/LIGHT FOG WILL BE CONFINED TO MORE
RURAL AREAS SUNDAY MORNING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH THURSDAY...GENERALLY PREVAILING VFR...HOWEVER AN
AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ANY DAY.
FRIDAY...CHANCE OF THUNDERSTORMS.
IZZI
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
909 PM CDT SAT JUL 13 2013
.DISCUSSION...
903 PM CDT
CURRENT GRIDS/FORECAST IN GOOD SHAPE. MADE MINOR TWEAKS TO
TEMPS...DEW POINTS AND SKY GRIDS TO FIT CURRENT TRENDS. A FEW
PASSING CLOUDS FAR SOUTHERN PART OF FORECAST AREA ASSOCIATED WITH
WESTWARD MOVING UPPER LOW...OTHERWISE CLEAR SKIES EXPECTED THROUGH
THE OVERNIGHT. WITH LIGHT WINDS...SLOWLY INCREASING DEW POINTS AND
STAGNANT AIR MASS...SOME LIGHT HAZE CAN BE EXPECTED AROUND
SUNRISE...AWAY FROM THE CITY HEAT ISLAND...BUT NOT SIGNIFICANT
ENOUGH TO MENTION IN FORECAST AT THIS TIME.
ALLSOPP
&&
.PREV DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NONE
IZZI
//DISCUSSION...UPDATED 00Z...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LAKE BREEZE WILL
DEVELOP AND MOVE THRU THE CHICAGO TERMINALS AGAIN SUNDAY AFTERNOON
WITH WINDS TURNING EAST AND PICKING UP TO AROUND 10KT WITH OCNL
GUSTS TO 15KT IN THE AFTERNOON. SURFACE MOISTURE HAS BEEN SLOW TO
INCREASE...SO THINK ANY HAZE/LIGHT FOG WILL BE CONFINED TO MORE
RURAL AREAS SUNDAY MORNING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH THURSDAY...GENERALLY PREVAILING VFR...HOWEVER AN
AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ANY DAY.
FRIDAY...CHANCE OF THUNDERSTORMS.
IZZI
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
548 PM MDT SAT JUL 13 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 595DM RIDGE CENTERED OVER
TX/OK PANHANDLES WITH AXIS EXTENDING INTO THE NORTHERN PLAINS. A
CLOSED 578DM LOW OVER THE EASTERN OH RIVER VALLEY IS JUST DOWN
STREAM OF THIS FEATURE...WITH THE REMNANTS OF OVERNIGHT CONVECTION
IN THE NORTHERN PLAINS BEGINNING TO BECOME WRAPPED INTO THE FLOW
BETWEEN THESE FEATURES. A SHORTWAVE TROUGH IS CURRENTLY IN PLACE
OVER NE COLORADO...WITH THUNDERSTORMS ALREADY BEGINNING TO DEVELOP
OVER HIGHER TERRAIN IN ON WESTERN EXTENT OF THIS FEATURE. A SURFACE
TROUGH IS CURRENTLY CENTERED OVER THE NE PART OF OUR CWA AND EXTENDS
SOUTH AND WEST INTO SOUTHEAST COLORADO.
TD VALUES HAVE MIXED DOWN OVER EASTERN PARTS OF THE CWA...RESULTING
IN SLIGHTLY LOWER HEAT INDICES THAN ORIGINALLY ANTICIPATED. AT THE
SAME TIME CRITERIA IS BEING MET AT NORTON...AND WE HAVENT REACHED
PEAK HEATING YET...SO WILL PLAN ON LEAVING HEAT ADVISORY AS IS.
GUIDANCE CONTINUES TO SUPPORT THUNDERSTORMS INITIATING ALONG AND
BEHIND THE SURFACE TROUGH OVER OUR CWA...WITH BETTER COVERAGE CLOSER
TO H7/H5 SHORTWAVE TROUGH IN NORTHEAST COLORADO. LATEST RAP ANALYSIS
SHOWS AXIS OF 1500-2000 J/KG ML CAPE EXTENDING ACROSS CWA. SHEAR ISNT
VERY IMPRESSIVE...BUT WITH INVERTED V AND GOOD MOISTURE ABOVE DRY
LAYER STRONG GUSTS WILL BE A CONCERN WITH ANY THUNDERSTORMS.
GUIDANCE ACTUALLY SHOWS ACTIVITY CONTINUE THROUGH MOST OF THE
NIGHT...HOWEVER WITH SHORTWAVE WEAKENING AND MOVING NORTH AND EAST
IM LESS CONFIDENT IN THIS ACTIVITY LINGERING PAST 06Z.
CLOSED LOW OVER OH RIVER VALLEY WITH MOVE EAST INTO THE SOUTHERN
PLAINS SUNDAY WITH DEEP EASTERLY FLOW DEVELOPING ACROSS THE
CWA...AND COLD FRONT MOVING INTO THE REGION FROM THE SOUTHEAST LATE
IN THE AFTERNOON. BEST CONVERGENCE/LARGE SCALE ASCENT WILL LIKELY BE
ALONG FRONT RANGE EXTENDING INTO OUR EASTERN CO COUNTIES WHERE AXIS
OF STRONG VORTICITY ON NW QUAD OF UPPER LOW WILL COMBINE WITH STRONG
UPSLOPE TO PRODUCE SHOWERS AND THUNDERSTORMS. GUIDANCE CONTINUES TO
SHOW DECENT INSTABILITY IN PLACE...AND WITH PWATS IN EXCESS OF 1.5
INCHES WE COULD SEE NUMEROUS THUNDERSTORMS WITH HEAVY RAIN. I
TRENDED POPS UP DURING THE AFTERNOON TO LIKELY CATEGORY DURING
AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
SUNDAY EVENING THE FRONT WILL CONTINUE TO MOVE WEST...WITH THE
BEST INSTABILITY AND LIFT REMAINING OVER THE TROUGH. WITH LITTLE
CIHN TO HOLD BACK CONVECTION AND SURFACE CONVERGENCE SERVING AS A
TRIGGER...STORMS SHOULD NOT HAVE MUCH PROBLEM DEVELOPING. THE BEST
CHANCE FOR STORM DEVELOPMENT WILL BE OVER THE EAST CENTRAL
COLORADO AND PARTS OF FAR SOUTHWEST NEBRASKA WITH PRECIP. CHANCES
DECLINING TO THE EAST AS LIFT AND INSTABILITY TAPER OFF. AS THE
EVENING PROGRESSES THE SURFACE TROUGH WILL GRADUALLY MOVE WEST OUT
OF THE AREA...WITH BE BETTER PRECIP. CHANCES FOLLOWING IT.
MEANWHILE DRIER MORE STABLE AIR WILL BE MOVING IN FROM THE EAST
ACCOMPANYING AN INVERTED SURFACE RIDGE. THE DRIER AIR WILL HAVE
MOVED ACROSS ENTIRE AREA BY LATE IN THE NIGHT.
STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE NORTHWEST PART OF
THE AREA NEAR THE SURFACE TROUGH WHERE A CORRIDOR OF MIXED 1KM MOST
UNSTABLE CAPE IN EXCESS OF 2000J/KG WILL BE LOCATED. THE LIMITING
FACTOR WILL BE THE LOW 0-6KM SHEAR OF 15-20KTS...WHICH MAY BE
ENOUGH FOR AN ISOLATED SUPERCELL TO DEVELOP GIVEN THE ADEQUATE CAPE.
MEAN STORM MOTIONS WILL BE TO THE SOUTHEAST OVER EAST CENTRAL
COLORADO...SO THERE MAY BE SOME TRAINING ALONG THE SURFACE TROUGH
LEADING TO LOCALLY HEAVY RAINFALL IN THE EVENING.
MONDAY THE SURFACE RIDGE SLIDES SOUTH AS ANOTHER WAVE OF MOISTURE
MOVES OVER THE SOUTHERN HALF OF THE AREA AROUND THE UPPER LEVEL LOW
TO THE SOUTH DURING THE AFTERNOON. TOWARD LATE AFTERNOON A WAVE OF WEAK
LIFT DEVELOPS OVER THE FAR SOUTHERN PART OF THE AREA...THEN
DISSIPATES BY EARLY EVENING. THIS MAY BE ENOUGH LIFT FOR AN
ISOLATED STORM TO DEVELOP.
TUESDAY THROUGH SATURDAY WILL BE DRY FOR THE MAJORITY OF THE PERIOD
AS THE UPPER LEVEL RIDGE OVER THE EAST CONUS BUILDS WEST AND BECOMES
ESTABLISHED OVER THE WESTERN CONUS TOWARD THE END OF THE WORK WEEK.
DURING THE WEEKEND AN UPPER LEVEL SHORT WAVE TROUGH DEVELOPS OVER
THE NORTHERN ROCKIES AND MOVES SOUTHEAST OVER THE AREA. A COLD
FRONT WILL ACCOMPANY THE UPPER LEVEL FEATURE WHICH WILL AID THE LIFT
OF THE TROUGH. BEING A WEEK OUT THERE IS STILL A GOOD DEAL OF
UNCERTAINTY AS TO WHERE THE TROUGH WILL TRACK AND IF IT WILL BE DEEP
ENOUGH TO DEVELOP STORMS. WOULD NOT TAKE TOO MUCH OF A SHIFT IN THE
POSITION OF THE RIDGE OVER THE ROCKIES TO PUSH THE UPPER LEVEL
TROUGH NORTH OF THE AREA. AS SUCH WILL LEAVE PRECIP. CHANCES JUST
BELOW 50% FOR THE ENTIRE AREA FOR SATURDAY. HIGH TEMPERATURES FOR
THE PERIOD WILL GRADUALLY WARM AS THE RIDGE BUILDS EAST. NEAR
NORMAL VALUES THROUGH MID WEEK WILL WARM TO ABOVE NORMAL BY FRIDAY
WITH HIGHS RANGING FROM BELOW TO ABOVE NORMAL SATURDAY AS THE COLD
FRONT MOVES THROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 544 PM MDT SAT JUL 13 2013
VFR CONDITIONS ARE EXPECTED AT BOTH SITES THROUGH THE 24 HOUR
PERIOD. ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED THIS
AFTERNOON ACROSS THE AREA. CONFIDENCE IS HIGHER FOR BRIEF IMPACT
FROM A SHOWER OR THUNDERSTORM AT MCK OVER THE NEXT COUPLE OF HOURS.
THE MOST CONCENTRATED AREA OF CONVECTION THIS EVENING HAS BEEN OVER
EAST CENTRAL COLORADO. OUTFLOW FROM THIS ACTIVITY COULD REACH
GOODLAND LATER THIS EVENING. THIS IN ADDITION TO THE CLOSE
PROXIMITY OF A SURFACE TROUGH AXIS WILL LIKELY RESULT IN SOME
VARIABILITY IN WIND DIRECTION...ALTHOUGH WIND SPEEDS SHOULD REMAIN
RELATIVELY LIGHT. TOMORROW...AN UPPER LEVEL LOW WILL APPROACH THE
AREA FROM THE WEST RESULTING IN A GRADUAL INCREASE OF CLOUDS.
CEILINGS SHOULD REMAIN IN VFR CATEGORY. SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP BY AFTERNOON AND COULD IMPACT EITHER TAF
SITE MAINLY AFTER 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ002>004-016.
CO...NONE.
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ080-081.
&&
$$
SHORT TERM...DJR
LONG TERM...JTL
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 PM MDT FRI JUL 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1255 PM MDT FRI JUL 12 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 593 DM RIDGE EXTENDING
ACROSS THE PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY...WITH CLOSED
576 DM LOW OVER OHIO RIVER VALLEY DOWNSTREAM...AND TROUGH IN PLACE
ACROSS PACIFIC NORTHWEST. THIS RIDGE WILL KEEP VERY HOT TEMPS IN
PLACE THE NEXT FEW DAYS WITH MINIMAL PRECIP CHANCES.
IMMEDIATE CONCERN IS VERY HOT TEMPERATURES ACROSS THE AREA THIS
AFTERNOON. SOUTHERLY FLOW HAS KEPT TD VALUES AROUND 60F IN PLACE
ACROSS THE EASTERN PART OF OUR CWA...WHICH SHOULD SUPPORT HEAT
INDICES AROUND 105F DURING PEAK HEATING. THOUGH I COULD SEE THIS AS
A MARGINAL SITUATION...PER COORDINATION AND LOCAL GUIDANCE I WENT
AHEAD AND ISSUED AT HEAT ADVISORY THROUGH 00Z.
SHORT RANGE GUIDANCE CONTINUES TO SUPPORT THUNDERSTORM INITIATION
ALONG SURFACE TROUGH AXIS NEAR OUR CWA BORDER. WITHOUT LARGE SCALE
FORCING IN PLACE...THIS ACTIVITY WILL PROBABLY BE TIED TO PEAK
HEATING...WITH CHANCES QUICKLY DIMINISHING AFTER SUNSET. I WENT
AHEAD AND INCLUDED ISO THUNDER MENTION...THOUGH CONFIDENCE IS PRETTY
LOW. LCL VALUES ARE GENERALLY IN THE 12-14KFT RANGE AND WITH DEEP
DRY LAYER BELOW WE MAY NOT ACTUALLY SEE MUCH REGARDING MEASURABLE
PRECIP WITH ANY OF THESE STORMS THAT DO DEVELOP. WITH DCAPE IN
EXCESS OF 1500 J/KG IS ALSO FORECAST BY BOTH RAP AND NAM BY THIS
AFTERNOON...SO STRONG GUSTS ARE CERTAINLY POSSIBLE WITH THESE STORMS.
SURFACE TROUGH BEGINS TO SHIFT SOUTH AND EAST SATURDAY...WHICH COULD
ALLOW SLIGHTLY COOLER TEMPS (AT LEAST SUB 100F) TO MOVE INTO THE
NORTHWEST PART OF THE CWA. THIS COULD ALSO SHIFT SW FLOW FURTHER
SOUTH KEEPING TD VALUES LOWER WHERE HIGHEST TEMPS ARE...SO CHANCE
FOR HEAT INDICES AROUND 105 SEEMS MUCH LOWER. GUIDANCE IS STILL
SHOWING THUNDERSTORMS INITIATING IN THE EARLY AFTERNOON ALONG AND
BEHIND THIS TROUGH AXIS. IT LOOKS LIKE A VERY SIMILAR SITUATION AS
TODAY WITH LITTLE IN THE WAY OF FORCING BEYOND DESTABILIZATION ALONG
TROUGH AXIS IN THE AFTERNOON/EVENING. WE COULD SEE INITIATION FURTHER
EAST DEPENDING ON TROUGH LOCATION. AT THIS TIME I DECIDED AGAINST
EXPANDING POPS TOO FAR EAST...THOUGH NAM WOULD SUPPORT ACTIVITY OVER
MOST OF OUR CWA BY 00Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 225 PM MDT FRI JUL 12 2013
UPPER FLOW WILL BE IN TRANSITION SATURDAY NIGHT AS THE RIDGE SHIFTS
EAST AND A LOW RETROGRESSES WEST INTO THE MISSOURI RIVER VALLEY. THE
UPPER LOW WILL MOVE INTO THE SOUTHERN PLAINS BY SUNDAY EVENING AND
THE TEXAS PANHANDLE MONDAY. WEAK SURFACE LOW PRESSURE IS FORECAST TO
BE OVER EASTERN COLORADO/NEW MEXICO THROUGH SUNDAY. SURFACE HIGH
PRESSURE WILL RETROGRESS WEST INTO THE CENTRAL/SOUTHERN PLAINS
SUNDAY NIGHT AND MONDAY.
THE SURFACE TROUGH IN EASTERN COLORADO WILL SERVE AS A FOCUS FOR
THUNDERSTORM INITIATION SATURDAY EVENING AS THE NEXT IMPULSE COMES
THROUGH THE FLOW. MOISTURE IS LIMITED SO WILL STAY WITH A SLIGHT
CHANCE POP. DEEP EASTERLY FLOW WILL SET UP SUNDAY/SUNDAY NIGHT WITH
CONVERGENCE OVER THE HIGHER TERRAIN OF EASTERN COLORADO. THERE IS
GOOD LIFT OVER THE HIGHER TERRAIN SO PLAN TO GO WITH SLIGHT CHANCE
OVER MOST OF THE FA WITH CHANCE POPS OVER EASTERN COLORADO. FOR NOW
WILL KEEP MONDAY MORNING DRY BUT CANNOT RULE OUT SOME LINGERING
SHOWERS IN THE FAR WESTERN PORTIONS OF THE EASTERN COLORADO
ZONES. BY MONDAY AFTERNOON A SHORTWAVE AFFECTS THE SOUTHERN
FA AS IT ROTATES AROUND THE LOW INTO THE AREA. FOR NOW WILL GO WITH
SLIGHT CHANCE POPS FOR THIS FEATURE SINCE DYNAMICS ARE WEAK AND
TRANSITIONING WESTWARD.
TEMPERATURES ARE MORE CHALLENGING WITH 850 TEMPERATURES IN THE MID
20S INSTEAD OF THE MID 30S. AT THIS TIME MAX TEMPERATURES SUNDAY
WILL BE AROUND 90 WITH MID/UPPER 80S MONDAY. DEPENDING ON HOW MUCH
PRECIPITATION AND CLOUDS ARE AROUND COOLER MAX TEMPERATURES ARE
POSSIBLE. MIN TEMPERATURES WILL RANGE FROM THE UPPER 60S/LOWER 70S
SUNDAY NIGHT TO THE MID 60S MONDAY NIGHT.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...UPPER FLOW WILL BE
SOUTHEASTERLY WITH THE LOW OVER NEW MEXICO. THIS LOW WILL WEAKEN
WEDNESDAY NIGHT AND THURSDAY WITH A RIDGE BUILDING OVER THE PACIFIC
NORTHWEST FRIDAY. SURFACE HIGH PRESSURE WILL BE OVER THE REGION
MONDAY NIGHT. FROM TUESDAY THROUGH FRIDAY WEAK LOW PRESSURE WILL BE
OVER EASTERN COLORADO. NUMEROUS SHORTWAVES WILL COME THROUGH THE
FLOW PRODUCING AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE FA.
850 TEMPERATURES COOL TO THE UPPER TEENS AND MID 20S. THIS SHOULD
RESULT IN MAX TEMPERATURES RANGING FROM THE MID 80S TO AROUND 90.
MIN TEMPERATURES WILL RANGE IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1127 AM MDT FRI JUL 12 2013
VFR CONDITIONS WILL PREVAIL AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. A FEW HIGH BASED THUNDERSTORMS (12-14KFT)
WILL BE POSSIBLE THIS AFTERNOON AND EVENING OVER EASTERN
COLORADO...HOWEVER AT THIS TIME THIS ACTIVITY IS EXPECTED TO
REMAIN EAST OF BOTH TERMINALS. SOUTH WINDS 12-14KT WITH
OCCASIONAL GUSTS 20-25KT ARE EXPECTED AT BOTH TERMINALS THIS
AFTERNOON...WITH DECREASING WINDS OVERNIGHT AS TROUGH AXIS SHIFTS
EAST AND GRADIENT WEAKENS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ003-004-015-016.
CO...NONE.
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ080-081.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1255 PM MDT FRI JUL 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1255 PM MDT FRI JUL 12 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 593 DM RIDGE EXTENDING
ACROSS THE PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY...WITH CLOSED
576 DM LOW OVER OHIO RIVER VALLEY DOWNSTREAM...AND TROUGH IN PLACE
ACROSS PACIFIC NORTHWEST. THIS RIDGE WILL KEEP VERY HOT TEMPS IN
PLACE THE NEXT FEW DAYS WITH MINIMAL PRECIP CHANCES.
IMMEDIATE CONCERN IS VERY HOT TEMPERATURES ACROSS THE AREA THIS
AFTERNOON. SOUTHERLY FLOW HAS KEPT TD VALUES AROUND 60F IN PLACE
ACROSS THE EASTERN PART OF OUR CWA...WHICH SHOULD SUPPORT HEAT
INDICES AROUND 105F DURING PEAK HEATING. THOUGH I COULD SEE THIS AS
A MARGINAL SITUATION...PER COORDINATION AND LOCAL GUIDANCE I WENT
AHEAD AND ISSUED AT HEAT ADVISORY THROUGH 00Z.
SHORT RANGE GUIDANCE CONTINUES TO SUPPORT THUNDERSTORM INITIATION
ALONG SURFACE TROUGH AXIS NEAR OUR CWA BORDER. WITHOUT LARGE SCALE
FORCING IN PLACE...THIS ACTIVITY WILL PROBABLY BE TIED TO PEAK
HEATING...WITH CHANCES QUICKLY DIMINISHING AFTER SUNSET. I WENT
AHEAD AND INCLUDED ISO THUNDER MENTION...THOUGH CONFIDENCE IS PRETTY
LOW. LCL VALUES ARE GENERALLY IN THE 12-14KFT RANGE AND WITH DEEP
DRY LAYER BELOW WE MAY NOT ACTUALLY SEE MUCH REGARDING MEASURABLE
PRECIP WITH ANY OF THESE STORMS THAT DO DEVELOP. WITH DCAPE IN
EXCESS OF 1500 J/KG IS ALSO FORECAST BY BOTH RAP AND NAM BY THIS
AFTERNOON...SO STRONG GUSTS ARE CERTAINLY POSSIBLE WITH THESE STORMS.
SURFACE TROUGH BEGINS TO SHIFT SOUTH AND EAST SATURDAY...WHICH COULD
ALLOW SLIGHTLY COOLER TEMPS (AT LEAST SUB 100F) TO MOVE INTO THE
NORTHWEST PART OF THE CWA. THIS COULD ALSO SHIFT SW FLOW FURTHER
SOUTH KEEPING TD VALUES LOWER WHERE HIGHEST TEMPS ARE...SO CHANCE
FOR HEAT INDICES AROUND 105 SEEMS MUCH LOWER. GUIDANCE IS STILL
SHOWING THUNDERSTORMS INITIATING IN THE EARLY AFTERNOON ALONG AND
BEHIND THIS TROUGH AXIS. IT LOOKS LIKE A VERY SIMILAR SITUATION AS
TODAY WITH LITTLE IN THE WAY OF FORCING BEYOND DESTABILIZATION ALONG
TROUGH AXIS IN THE AFTERNOON/EVENING. WE COULD SEE INITIATION FURTHER
EAST DEPENDING ON TROUGH LOCATION. AT THIS TIME I DECIDED AGAINST
EXPANDING POPS TOO FAR EAST...THOUGH NAM WOULD SUPPORT ACTIVITY OVER
MOST OF OUR CWA BY 00Z.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 338 AM MDT FRI JUL 12 2013
WELL IT LOOKS LIKE THE 11TH/00Z ECMWF WAS ONTO SOMETHING WHEN IT WAS
AGGRESSIVE IN BRINGING AN UPPER LOW AND MUCH COOLER TEMPS INTO THE
REGION EARLY NEXT WEEK AS ALL OTHER GLOBAL GUIDANCE HAS NOW CAUGHT
ON AS OF THE 12Z AND 18Z SUITES. TONIGHTS 00Z GUIDANCE CONTINUES TO
MOVE THE RETROGRADING UPPER LOW FROM THE SOUTHERN PLAINS TO EASTERN
COLORADO ON MONDAY INTO TUESDAY. STILL HAVE SOME MINOR CONCERN ABOUT
JUST HOW FAST THE LOW RETROGRADES FROM THE MID-ATLANTIC TO THE
SOUTHERN PLAINS...AND WOULD NOT BE SURPRISED TO SEE MODEL TREND
SLIGHTLY SLOWER OVER THE NEXT FEW DAYS.
WX IMPACTS FROM THE LOW WILL BE INCREASED POPS AND COOLER
TEMPS...WITH BEST CHANCE FOR STORMS ON MONDAY SOUTH OF I-70. EC/GFS
MOS GIVE SOME 20-25 POPS ON TUES AS WELL...BUT GIVEN THE FACT THAT
THE UPPER LOW WILL BE DISSIPATING DURING THIS TIME DO NOT HAVE
ENOUGH CONFIDENCE TO INCLUDE MENTION OF STORMS DURING THIS TIME
PERIOD...THOUGH COULD EASILY SEE LINGERING OUTFLOW/ SURFACE
BOUNDARIES FROM CONVECTION ON MONDAY PROVIDING A TRIGGER FOR
CONVECTION ON TUESDAY. ON TEMPS THE TREND CONTINUES DOWN...WITH EC
MOS HAVING HIGHS ON MONDAY IN THE MID 70S AND GFS MOS IN THE MID
80S...QUITE A DOWNTURN FROM THE MID 90S ALL GUIDANCE /INCLUDING EC
AND GFS MOS/ PREDICTED JUST A FEW DAYS AGO. REST OF WEEK LOOKS TO BE
BELOW TO NEAR NORMAL ON TEMPS /MID 80S TO 90S FOR HIGHS/ WITH SILENT
POPS AS LARGE SCALE PATTERN TRANSITIONS TO A WEAK RIDGE OVER THE
CENTRAL US.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1127 AM MDT FRI JUL 12 2013
VFR CONDITIONS WILL PREVAIL AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. A FEW HIGH BASED THUNDERSTORMS (12-14KFT)
WILL BE POSSIBLE THIS AFTERNOON AND EVENING OVER EASTERN
COLORADO...HOWEVER AT THIS TIME THIS ACTIVITY IS EXPECTED TO
REMAIN EAST OF BOTH TERMINALS. SOUTH WINDS 12-14KT WITH
OCCASIONAL GUSTS 20-25KT ARE EXPECTED AT BOTH TERMINALS THIS
AFTERNOON...WITH DECREASING WINDS OVERNIGHT AS TROUGH AXIS SHIFTS
EAST AND GRADIENT WEAKENS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ003-004-015-016.
CO...NONE.
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ080-081.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1230 PM CDT FRI JUL 12 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI JUL 12 2013
THE WEATHER PATTERN THIS MORNING DEPICTS THE MID LEVEL RIDGE AXIS
STRETCHING ACROSS THE CENTRAL AND NORTHERN PLAINS. THE RIDGE IS
EXPECTED TO EXPAND NORTHEASTWARD LATER TODAY ESSENTIALLY CUTTING OFF
THE FLOW FROM THE UPPER TROUGH ROTATING OVER THE MID ATLANTIC REGION.
AT THE 08Z HOUR A SUBTLE PERTURBATION EMBEDDED WITHIN THE RIDGE WAS
NOTED OVER SOUTHEAST WYOMING. THE LATEST HRRR AND RAP HAVE TRIED TO
GENERATE PRECIP FOR THE PREVIOUS FEW HOURS NOTING MULTIPLE WEAK
SHORTWAVE TROUGHS THAT ARE NOT OBSERVED IN REAL TIME. AND SINCE NO
FORCING IS APPARENT WILL THEREFORE MONITOR BUT MAINTAIN A DRY
FORECAST FOR THE MORNING PERIOD. A WARMER AND WINDY FRIDAY IS IN
STORE FOR NORTHEAST KANSAS. SURFACE HEATING AND A TIGHTENING
PRESSURE GRADIENT FROM THE H85 SHORTWAVE TROUGH OVER EASTERN
COLORADO WILL PICKUP SOUTHERLY WINDS BETWEEN FROM 15 TO 20 MPH.
THIS WILL ALSO INCREASE WARMER AIR FLOWING INTO THE AREA WITH
READINGS FROM THE LOW 90S IN EAST CENTRAL AREAS...TO THE UPPER 90S
OVER NORTH CENTRAL KS. MOISTURE ADVECTING NORTHWARD WILL KEEP
DEWPOINTS IN THE LOW TO MIDDLE 60S...TRANSLATING TO HEAT INDICES
BETWEEN 100 AND 105 DEGREES OVER NORTH CENTRAL KS. QUIET WEATHER
CONTINUES INTO FRIDAY EVENING WITH STEADY SOUTHEAST WINDS KEEPING
TEMPERATURES WARMER THAN THIS MORNING IN UPPER 60S TO MID 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI JUL 12 2013
FOR SATURDAY THROUGH SUNDAY NIGHT...THE MAIN FOCUS FOR THE
FORECAST IS A RETROGRADING CLOSED LOW MOVING FROM THE TN VALLEY
INTO THE SOUTHERN HIGH PLAINS. MODELS SEEM TO BE SLIGHTLY FASTER
WITH THE PROGRESSION OF THE CLOSED UPPER LOW AND BY SUNDAY NIGHT
HAVE IT OVER THE HIGH PLAINS. ALSO THE MAJORITY OF MODEL SOLUTIONS
TAKE THE UPPER LOW SOUTH OF THE FORECAST AREA WITH THE BETTER
LARGE SCALE FORCING OVER SOUTHERN KS AND OK. CURIOUSLY IT APPEARS
AS THOUGH THERE IS NOT MUCH MID LEVEL MOISTURE ACCOMPANYING THE
LOW WITH THE NAM AND GFS ACTUALLY SHOWING PWS DRYING WITH SURFACE
DEWPOINT TEMPS COOLING AS THE UPPER LOW APPROACHES. ADDITIONALLY
THE MID LEVEL LAPSE RATES ARE PRETTY CLOSE TO THE MOIST ADIABATIC
LAPSE RATE SO THERE IS LITTLE OR NO INSTABILITY ABOVE THE LCL. SO
IN GENERAL AM NOT OVERLY EXCITED ABOUT PRECIP CHANCES THROUGH THE
WEEKEND. WILL KEEP A SLIGHT CHANCE FOR SOME SHOWERS SUNDAY ACROSS
EAST CENTRAL KS THINKING THIS IS THE MOST LIKELY TIME FRAME FOR
THE UPPER LOW TO MOVE THROUGH SOUTHEAST KS. SINCE THERE DOES NOT
APPEAR TO BE ANY INSTABILITY...HAVE REMOVED THE MENTION OF THUNDER
FROM THE FORECAST FOR SUNDAY. HIGHS SHOULD BE TRENDING COOLER
THROUGH THE WEEKEND...ESPECIALLY FOR SUNDAY AS MODELS SHOW LOW
LEVEL COLD AIR ADVECTION FROM THE SOUTHEAST. HIGHS IN THE 90S FOR
SATURDAY SHOULD COOL INTO THE MID 80S TO AROUND 90 FOR SUNDAY.
LOWS WILL ALSO TREND COOLER WITH READINGS FOR SUNDAY MORNING
EXPECTED TO BE IN THE 60S AS SURFACE RIDGING FROM THE EAST
PERSISTS.
MONDAY THROUGH TUESDAY IS A LITTLE MORE UNCERTAIN AS MODELS START
TO DIVERGE ON THE TRACK OF THE CLOSED LOW. THERE IS THE
POSSIBILITY THAT THE UPPER LOW GETS HUNG UP OVER THE HIGH PLAINS
WITH PIECES OF ENERGY ROTATING NORTH INTO THE STATE. BECAUSE OF
THIS HAVE HELD ONTO SOME SLIGHT CHANCE POPS DURING THE DAY MONDAY
AND TUESDAY THINKING THERE COULD BE SOME POP UP STORMS IF THE
UPPER LOW IS JUST TO THE WEST OF THE FORECAST AREA. HIGHS ARE
FORECAST TO REMAIN NEAR NORMAL WITH READINGS AROUND 90. SOUTHERLY
WINDS AND A GRADUAL INCREASE IN LOW LEVEL MOISTURE SHOULD KEEP
LOWS AROUND 70 TO THE LOWER 70S.
THE GFS AND ECMWF SHOW WEAK MID LEVEL RIDGING NOSING INTO EASTERN
KS FROM THE EAST WITH NO REAL SURFACE FEATURE TO FOCUS LIFT OF A
SURFACE PARCEL. BECAUSE OF THIS HAVE MAINTAINED A DRY FORECAST.
TEMPS SHOULD SEE A GRADUAL WARMING TREND AS MID LEVEL HEIGHTS
RISE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1229 PM CDT FRI JUL 12 2013
FOR THE 18Z TAFS...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS
THROUGH THE PERIOD WILL REMAIN LIGHT OUT OF THE SOUTHEAST WITH MID
LEVEL CLOUDS BUILDING INTO THE REGION BY SATURDAY MORNING.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...HENNECKE
AREA FORECAST DISCUSSION
NWS TOPEKA KS
624 AM CDT FRI JUL 12 2013
...UPDATE TO AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI JUL 12 2013
THE WEATHER PATTERN THIS MORNING DEPICTS THE MID LEVEL RIDGE AXIS
STRETCHING ACROSS THE CENTRAL AND NORTHERN PLAINS. THE RIDGE IS
EXPECTED TO EXPAND NORTHEASTWARD LATER TODAY ESSENTIALLY CUTTING OFF
THE FLOW FROM THE UPPER TROUGH ROTATING OVER THE MID ATLANTIC REGION.
AT THE 08Z HOUR A SUBTLE PERTURBATION EMBEDDED WITHIN THE RIDGE WAS
NOTED OVER SOUTHEAST WYOMING. THE LATEST HRRR AND RAP HAVE TRIED TO
GENERATE PRECIP FOR THE PREVIOUS FEW HOURS NOTING MULTIPLE WEAK
SHORTWAVE TROUGHS THAT ARE NOT OBSERVED IN REAL TIME. AND SINCE NO
FORCING IS APPARENT WILL THEREFORE MONITOR BUT MAINTAIN A DRY
FORECAST FOR THE MORNING PERIOD. A WARMER AND WINDY FRIDAY IS IN
STORE FOR NORTHEAST KANSAS. SURFACE HEATING AND A TIGHTENING
PRESSURE GRADIENT FROM THE H85 SHORTWAVE TROUGH OVER EASTERN
COLORADO WILL PICKUP SOUTHERLY WINDS BETWEEN FROM 15 TO 20 MPH.
THIS WILL ALSO INCREASE WARMER AIR FLOWING INTO THE AREA WITH
READINGS FROM THE LOW 90S IN EAST CENTRAL AREAS...TO THE UPPER 90S
OVER NORTH CENTRAL KS. MOISTURE ADVECTING NORTHWARD WILL KEEP
DEWPOINTS IN THE LOW TO MIDDLE 60S...TRANSLATING TO HEAT INDICES
BETWEEN 100 AND 105 DEGREES OVER NORTH CENTRAL KS. QUIET WEATHER
CONTINUES INTO FRIDAY EVENING WITH STEADY SOUTHEAST WINDS KEEPING
TEMPERATURES WARMER THAN THIS MORNING IN UPPER 60S TO MID 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI JUL 12 2013
FOR SATURDAY THROUGH SUNDAY NIGHT...THE MAIN FOCUS FOR THE
FORECAST IS A RETROGRADING CLOSED LOW MOVING FROM THE TN VALLEY
INTO THE SOUTHERN HIGH PLAINS. MODELS SEEM TO BE SLIGHTLY FASTER
WITH THE PROGRESSION OF THE CLOSED UPPER LOW AND BY SUNDAY NIGHT
HAVE IT OVER THE HIGH PLAINS. ALSO THE MAJORITY OF MODEL SOLUTIONS
TAKE THE UPPER LOW SOUTH OF THE FORECAST AREA WITH THE BETTER
LARGE SCALE FORCING OVER SOUTHERN KS AND OK. CURIOUSLY IT APPEARS
AS THOUGH THERE IS NOT MUCH MID LEVEL MOISTURE ACCOMPANYING THE
LOW WITH THE NAM AND GFS ACTUALLY SHOWING PWS DRYING WITH SURFACE
DEWPOINT TEMPS COOLING AS THE UPPER LOW APPROACHES. ADDITIONALLY
THE MID LEVEL LAPSE RATES ARE PRETTY CLOSE TO THE MOIST ADIABATIC
LAPSE RATE SO THERE IS LITTLE OR NO INSTABILITY ABOVE THE LCL. SO
IN GENERAL AM NOT OVERLY EXCITED ABOUT PRECIP CHANCES THROUGH THE
WEEKEND. WILL KEEP A SLIGHT CHANCE FOR SOME SHOWERS SUNDAY ACROSS
EAST CENTRAL KS THINKING THIS IS THE MOST LIKELY TIME FRAME FOR
THE UPPER LOW TO MOVE THROUGH SOUTHEAST KS. SINCE THERE DOES NOT
APPEAR TO BE ANY INSTABILITY...HAVE REMOVED THE MENTION OF THUNDER
FROM THE FORECAST FOR SUNDAY. HIGHS SHOULD BE TRENDING COOLER
THROUGH THE WEEKEND...ESPECIALLY FOR SUNDAY AS MODELS SHOW LOW
LEVEL COLD AIR ADVECTION FROM THE SOUTHEAST. HIGHS IN THE 90S FOR
SATURDAY SHOULD COOL INTO THE MID 80S TO AROUND 90 FOR SUNDAY.
LOWS WILL ALSO TREND COOLER WITH READINGS FOR SUNDAY MORNING
EXPECTED TO BE IN THE 60S AS SURFACE RIDGING FROM THE EAST
PERSISTS.
MONDAY THROUGH TUESDAY IS A LITTLE MORE UNCERTAIN AS MODELS START
TO DIVERGE ON THE TRACK OF THE CLOSED LOW. THERE IS THE
POSSIBILITY THAT THE UPPER LOW GETS HUNG UP OVER THE HIGH PLAINS
WITH PIECES OF ENERGY ROTATING NORTH INTO THE STATE. BECAUSE OF
THIS HAVE HELD ONTO SOME SLIGHT CHANCE POPS DURING THE DAY MONDAY
AND TUESDAY THINKING THERE COULD BE SOME POP UP STORMS IF THE
UPPER LOW IS JUST TO THE WEST OF THE FORECAST AREA. HIGHS ARE
FORECAST TO REMAIN NEAR NORMAL WITH READINGS AROUND 90. SOUTHERLY
WINDS AND A GRADUAL INCREASE IN LOW LEVEL MOISTURE SHOULD KEEP
LOWS AROUND 70 TO THE LOWER 70S.
THE GFS AND ECMWF SHOW WEAK MID LEVEL RIDGING NOSING INTO EASTERN
KS FROM THE EAST WITH NO REAL SURFACE FEATURE TO FOCUS LIFT OF A
SURFACE PARCEL. BECAUSE OF THIS HAVE MAINTAINED A DRY FORECAST.
TEMPS SHOULD SEE A GRADUAL WARMING TREND AS MID LEVEL HEIGHTS
RISE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 557 AM CDT FRI JUL 12 2013
VFR PREVAILS THROUGH 12Z SATURDAY AT KTOP/KFOE/KMHK AS LIGHT EAST
WINDS VEER TO THE SOUTHEAST AND INCREASE AOA 12 KTS AFT 15Z. AT KMHK
GUSTS WERE INCLUDED NEAR 20 KTS WHERE TERMINAL IS CLOSEST TO
TIGHTER PRESSURE GRADIENT FROM SURFACE TROUGH OVER EASTERN COLORADO.
WINDS WEAKEN BLO 10 KTS AFT 02Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
320 AM CDT FRI JUL 12 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI JUL 12 2013
THE WEATHER PATTERN THIS MORNING DEPICTS THE MID LEVEL RIDGE AXIS
STRETCHING ACROSS THE CENTRAL AND NORTHERN PLAINS. THE RIDGE IS
EXPECTED TO EXPAND NORTHEASTWARD LATER TODAY ESSENTIALLY CUTTING OFF
THE FLOW FROM THE UPPER TROUGH ROTATING OVER THE MID ATLANTIC REGION.
AT THE 08Z HOUR A SUBTLE PERTURBATION EMBEDDED WITHIN THE RIDGE WAS
NOTED OVER SOUTHEAST WYOMING. THE LATEST HRRR AND RAP HAVE TRIED TO
GENERATE PRECIP FOR THE PREVIOUS FEW HOURS NOTING MULTIPLE WEAK
SHORTWAVE TROUGHS THAT ARE NOT OBSERVED IN REAL TIME. AND SINCE NO
FORCING IS APPARENT WILL THEREFORE MONITOR BUT MAINTAIN A DRY
FORECAST FOR THE MORNING PERIOD. A WARMER AND WINDY FRIDAY IS IN
STORE FOR NORTHEAST KANSAS. SURFACE HEATING AND A TIGHTENING
PRESSURE GRADIENT FROM THE H85 SHORTWAVE TROUGH OVER EASTERN
COLORADO WILL PICKUP SOUTHERLY WINDS BETWEEN FROM 15 TO 20 MPH.
THIS WILL ALSO INCREASE WARMER AIR FLOWING INTO THE AREA WITH
READINGS FROM THE LOW 90S IN EAST CENTRAL AREAS...TO THE UPPER 90S
OVER NORTH CENTRAL KS. MOISTURE ADVECTING NORTHWARD WILL KEEP
DEWPOINTS IN THE LOW TO MIDDLE 60S...TRANSLATING TO HEAT INDICES
BETWEEN 100 AND 105 DEGREES OVER NORTH CENTRAL KS. QUIET WEATHER
CONTINUES INTO FRIDAY EVENING WITH STEADY SOUTHEAST WINDS KEEPING
TEMPERATURES WARMER THAN THIS MORNING IN UPPER 60S TO MID 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI JUL 12 2013
FOR SATURDAY THROUGH SUNDAY NIGHT...THE MAIN FOCUS FOR THE
FORECAST IS A RETROGRADING CLOSED LOW MOVING FROM THE TN VALLEY
INTO THE SOUTHERN HIGH PLAINS. MODELS SEEM TO BE SLIGHTLY FASTER
WITH THE PROGRESSION OF THE CLOSED UPPER LOW AND BY SUNDAY NIGHT
HAVE IT OVER THE HIGH PLAINS. ALSO THE MAJORITY OF MODEL SOLUTIONS
TAKE THE UPPER LOW SOUTH OF THE FORECAST AREA WITH THE BETTER
LARGE SCALE FORCING OVER SOUTHERN KS AND OK. CURIOUSLY IT APPEARS
AS THOUGH THERE IS NOT MUCH MID LEVEL MOISTURE ACCOMPANYING THE
LOW WITH THE NAM AND GFS ACTUALLY SHOWING PWS DRYING WITH SURFACE
DEWPOINT TEMPS COOLING AS THE UPPER LOW APPROACHES. ADDITIONALLY
THE MID LEVEL LAPSE RATES ARE PRETTY CLOSE TO THE MOIST ADIABATIC
LAPSE RATE SO THERE IS LITTLE OR NO INSTABILITY ABOVE THE LCL. SO
IN GENERAL AM NOT OVERLY EXCITED ABOUT PRECIP CHANCES THROUGH THE
WEEKEND. WILL KEEP A SLIGHT CHANCE FOR SOME SHOWERS SUNDAY ACROSS
EAST CENTRAL KS THINKING THIS IS THE MOST LIKELY TIME FRAME FOR
THE UPPER LOW TO MOVE THROUGH SOUTHEAST KS. SINCE THERE DOES NOT
APPEAR TO BE ANY INSTABILITY...HAVE REMOVED THE MENTION OF THUNDER
FROM THE FORECAST FOR SUNDAY. HIGHS SHOULD BE TRENDING COOLER
THROUGH THE WEEKEND...ESPECIALLY FOR SUNDAY AS MODELS SHOW LOW
LEVEL COLD AIR ADVECTION FROM THE SOUTHEAST. HIGHS IN THE 90S FOR
SATURDAY SHOULD COOL INTO THE MID 80S TO AROUND 90 FOR SUNDAY.
LOWS WILL ALSO TREND COOLER WITH READINGS FOR SUNDAY MORNING
EXPECTED TO BE IN THE 60S AS SURFACE RIDGING FROM THE EAST
PERSISTS.
MONDAY THROUGH TUESDAY IS A LITTLE MORE UNCERTAIN AS MODELS START
TO DIVERGE ON THE TRACK OF THE CLOSED LOW. THERE IS THE
POSSIBILITY THAT THE UPPER LOW GETS HUNG UP OVER THE HIGH PLAINS
WITH PIECES OF ENERGY ROTATING NORTH INTO THE STATE. BECAUSE OF
THIS HAVE HELD ONTO SOME SLIGHT CHANCE POPS DURING THE DAY MONDAY
AND TUESDAY THINKING THERE COULD BE SOME POP UP STORMS IF THE
UPPER LOW IS JUST TO THE WEST OF THE FORECAST AREA. HIGHS ARE
FORECAST TO REMAIN NEAR NORMAL WITH READINGS AROUND 90. SOUTHERLY
WINDS AND A GRADUAL INCREASE IN LOW LEVEL MOISTURE SHOULD KEEP
LOWS AROUND 70 TO THE LOWER 70S.
THE GFS AND ECMWF SHOW WEAK MID LEVEL RIDGING NOSING INTO EASTERN
KS FROM THE EAST WITH NO REAL SURFACE FEATURE TO FOCUS LIFT OF A
SURFACE PARCEL. BECAUSE OF THIS HAVE MAINTAINED A DRY FORECAST.
TEMPS SHOULD SEE A GRADUAL WARMING TREND AS MID LEVEL HEIGHTS
RISE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1143 PM CDT THU JUL 11 2013
VFR CONDITIONS THROUGH THE PERIOD. WINDS GENERALLY EAST SOUTHEAST
AND BECOME SUSTAINED OVER 12KTS IN THE AFTERNOON HOURS BEFORE
DECREASING ONCE AGAIN NEAR SUNSET. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...67
AREA FORECAST DISCUSSION
NWS WICHITA KS
1135 PM CDT THU JUL 11 2013
UPDATE FOR THE 06Z AVIATION SECTION.
.UPDATE...
ISSUED AT 831 PM CDT THU JUL 11 2013
OUTFLOW BOUNDARIES FROM EARLY AFTERNOON CONVECTION IN SE KS PUSHED
WELL INTO OK THIS EVENING...KEEPING ANY CONVECTIVE ACTIVITY WELL TO
THE SOUTH OF THE AREA. LATEST RUC DOES SHOW AN UNSTABLE AIRMASS
STILL ACROSS SOUTH CEN KS...BUT EML HAS CONTINUED TO WARM LEADING TO
LITTLE IF ANY CU DEVELOPMENT ACROSS SRN KS. EXPECTING WARMER TEMPS
ALOFT TO CONTINUE ACROSS THE FORECAST AREA LATE THIS EVENING AND
OVERNIGHT WHICH WILL KEEP THINGS MOSTLY CLEAR. SO WILL REMOVE
CONVECTIVE CHANCES OVER EXTREME SRN KS AND KEEP THINGS DRY
OVERNIGHT.
KETCHAM
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 246 PM CDT THU JUL 11 2013
RESIDUAL SHOWERS/STORMS WILL CONTINUE TO DRIFT SOUTHEAST THIS
AFTERNOON AND EVENING FROM MCV ALOFT...BUT SHOULD DECREASE RAPIDLY
JUST AFTER SUNSET. OTHERWISE THE HEAT AND HUMIDITY WILL BUILD BACK
OVER THE REGION FOR FRIDAY AND SATURDAY...AS THE UPPER LEVEL RIDGE
CENTER POSITIONS ITSELF OVER THE CENTRAL PLAINS. HEADING INTO SUNDAY
MODEL SOLUTIONS FOR THE PAST TWO CYCLES CONTINUE TO SHOW CURRENT
UPPER WAVE OVER THE GREAT LAKES CUTTING OFF THEN RETRO-GRADING
WESTWARD INTO KANSAS THIS PERIOD. WE WILL INTRODUCE SOME
PRECIPITATION CHANCES FOR SUNDAY AND LOWER DAYTIME TEMPERATURES A
BIT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 246 PM CDT THU JUL 11 2013
THE UPPER LOW WILL KEEP THINGS UNSETTLED FOR MONDAY/TUESDAY WITH
SCATTERED SHOWERS AND STORMS POSSIBLE...WITH THE COVERAGE MORE
WIDESPREAD DURING THE AFTERNOON/EVENING HOURS DUE TO DAYTIME
HEATING. DAYTIME HIGHS WILL BE AROUND OR SLIGHTLY BELOW NORMAL FOR
EARLY NEXT WEEK. MEANWHILE THE UPPER LEVEL RIDGE CENTER WILL BUILD
BACK OVER THE CENTRAL PLAINS FOR MID TO LATE WEEK.
JAKUB
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1133 PM CDT THU JUL 11 2013
VFR CONDITIONS WILL CONTINUE ACROSS THE AREA...FOR THE NEXT 24
HOURS. WILL SEE CLEAR SKIES ACROSS THE AREA AS MID LEVEL TEMPS WARM
KEEPING ANY CLOUDS FROM FORMING. COULD SEE A FEW MID LEVEL CLOUDS IN
AND NEAR THE KCNU TAF SITE ALONG A WEAK MID LEVEL BAROCLINIC ZONE.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 72 98 75 98 / 10 0 0 0
HUTCHINSON 72 100 76 100 / 10 0 0 0
NEWTON 71 98 75 98 / 10 0 0 0
ELDORADO 71 97 74 97 / 10 0 0 0
WINFIELD-KWLD 73 98 75 98 / 20 0 0 0
RUSSELL 72 103 76 102 / 10 0 0 0
GREAT BEND 73 103 76 102 / 10 0 0 0
SALINA 72 99 76 101 / 10 0 0 0
MCPHERSON 72 99 76 100 / 10 0 0 0
COFFEYVILLE 71 96 72 95 / 10 0 0 0
CHANUTE 69 96 70 94 / 10 0 0 0
IOLA 68 96 70 94 / 0 0 0 0
PARSONS-KPPF 70 96 71 95 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
650 PM EDT FRI JUL 12 2013
.SYNOPSIS...
COLD FRONT HAS STALLED ALONG THE COAST THIS AFTERNOON AND WILL
REMAIN OVER THE REGION THROUGH SATURDAY. HIGH PRESSURE WILL BUILD
INTO THE REGION FROM THE EAST THIS WEEKEND AS THE FRONT DISSIPATES
OVER THE AREA. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATED TO REMOVE CENTRAL VA FROM THE FLASH FLOOD WATCH AS THE
THREAT FOR HEAVY RAINFALL HAS ENDED. FOR THE REMAINDER OF THE
WATCH AREA...A FEW ISOLATED AREAS OF HEAVY RAIN REMAIN POSSIBLE
THROUGH THE EVENING...BUT THE OVERALL THREAT IS QUICKLY
DIMINISHING.
PREVIOUS DISCUSSION...
PER LATEST MSAS ANALYSIS AND SFC OBSERVATIONS...COLD FRONT HAS
STALLED ACROSS SE VA THIS AFTERNOON. LATEST WATER VAPOR IMAGERY
CONTINUES TO SHOW PLUME OF MOISTURE LIFTING THROUGH THE REGION AS
LOW PRESSURE TO THE WEST SLOWLY DRIFTS SWD. LOW POSITION WILL
CONTINUE TO BE IN A FAVORABLE POSITION FOR STRONG UPPER LEVEL
FORCING (STRONG DIFFLUENCE ALOFT) OVER THE LOCAL AREA. SEEING
COOLING CLOUD TOPS OVER CNTRL/ERN NC ATTM AS A SHORT WAVE LIFTS
FROM THE SE. EXPECT ANOTHER WAVE OF SHOWERS AND EMBEDDED
THUNDERSTORMS TO LIFT NWD ALONG THE FRONT INTO NE NC/SE VA THROUGH
6 PM AND INTO ERN VA (MAINLY EAST OF INTERSTATE 95) THROUGH EARLY
TONIGHT. HAVE OPTED TO DROP HEADLINES OVER THE PIEDMONT AS DRY AIR
HAS WORKED IN ALOFT. LATEST RADAR TRENDS AND HRRR RUNS BACK THIS
UP WELL. HAVE ALSO EXTENDED FLASH FLOOD WATCH HEADLINES UNTIL
MIDNIGHT TONIGHT ALONG AND EAST OF INTERSTATE 95 TO ACCOUNT FOR
THE NEXT WAVE AND SATURATED SOILS. EXPECT THE WAVE TO LIFT
THROUGH THE LOCAL AREA BY MIDNIGHT...BUT SHOWERS EXPECTED TO
CONTINUE ALONG THE FRONT OVER SE VA/NE NC THROUGH LATE TONIGHT.
TEMPS EXPECTED TO FALL INTO THE UPPER 60S/LOW 70S TONIGHT UNDER
CLOUDY SKIES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
MODELS CONTINUE TO HANDLE THE MID/UPPER LEVEL PATTERN WELL
THROUGH THE SHORT TERM. THE UPPER LOW WILL BECOME CUT OFF FROM THE
FLOW TONIGHT/SAT MORNING...AS HIGH PRESSURE STRENGTHENS OVER THE
CNTRL CONUS. THE LOW IS THEN PROGGED TO UNDERCUT THE
RIDGE...PROGRESSING SWWD THROUGH THE SHORT TERM TOWARD THE SRN
PLAINS. THIS WILL ALLOW UPPER/SFC HIGH PRESSURE TO BUILD INTO THE
REGION SAT...AND REMAINING CENTERED OVER THE OH VALLEY THROUGH THE
SHORT TERM. THE RESULT OVER THE LOCAL AREA WILL BE SUMMER LIKE
CONDITIONS WITH THE STORM TRACK REMAINING WELL TO THE NORTH OF THE
REGION. MOISTURE PLUME WILL MOVE INLAND AS UPPER LEVEL FLOW
BECOMES SELY SAT...WITH BEST POPS ACROSS THE PIEDMONT SAT
AFTERNOON. WHILE FORCING FOR ASCENT WILL BE SUBTLE...DIURNAL
FORCING AND ABUNDANT MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SAT AFTERNOON...WEST OF INTERSTATE 95. WILL KEEP
MENTION OF SLIGHT CHANCE POPS FOR THE PIEDMONT SUN AFTERNOON...BUT
BEST MOISTURE/DYNAMICS LOOKS TO BE WEST OF THE AREA. AREA WILL BE
UNDER THE INFLUENCE OF HIGH PRESSURE MON...BUT DO EXPECT MOISTURE
TO ADVECT FROM THE WRN ATLANTIC INTO THE REGION. PRESENCE OF A
WEAK LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES UNDER WEAK FLOW
ALOFT...MAY RESULT IN ISOLATED-WIDELY SCATTERED THUNDERSTORMS
ACROSS THE LOCAL AREA. WILL MAINTAIN SLIGHT CHANCE POPS DURING THE
AFTERNOON FOR DIURNAL FORCING.
NEAR SEASONABLE NORMAL TEMPS SAT UNDER CLEARING SKIES FROM E TO
W. WARMING TREND WILL COMMENCE SUN AS STRONG HEIGHT RISES AND
INCREASING LOW LEVEL THICKNESS VALUES PUSH TEMPS INTO THE LOW 90S.
HOWEVER...SE FLOW WILL PREVENT TEMPS FROM REACHING THEIR FULL
POTENTIAL (HIGHS GENERALLY IN THE LOW 90S). SLIGHTLY WARMER MONDAY
AS WINDS BECOME MORE SLY (HIGHS IN THE LOW 90S). TEMPS ALONG THE
COAST DURING THE SHORT TERM WILL BE SLIGHTLY COOLER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HOTTER AND DRIER WEATHER EXPECTED NEXT WEEK...
MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG H5 RIDGE (599DM)
RESIDING OVER THE OHIO VALLEY TUESDAY/WEDNESDAY OF NEXT WEEK. THE
RIDGE THEN SLOWLY SHIFTS EAST OVER THE MID-ATLANTIC REGION THURSDAY
BEFORE MOVING EAST TO OFF THE CAROLINA COAST BY NEXT FRIDAY. THE
POSITION AND STRENGTH OF THIS RIDGE POINTS TO A SPELL OF HOT WEATHER
ACROSS THE LOCAL AREA NEXT WEEK WITH MAX TEMPS RUNNING ABOUT 1
STANDARD DEVIATION ABOVE NORMAL (MID 90S). THIS STAGNANT AIRMASS
WILL ALSO RESULT IN WARM/MUGGY NIGHTS WITH LOWS IN THE MID/UPR 70S.
LITTLE OPPORTUNITY FOR PCPN WILL OCCUR IN THIS PATTERN AS WELL
OUTSIDE OF ISOLD CONVECTION OVER THE HIGHER TERRAIN TO OUR WEST OUR
ALONG THE AFTN SEA BREEZE. WILL GO NO HIGHER THAN SLIGHT CHC (20%)
POPS THROUGH THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A WEAK STNRY FRONT LINGERS OVER EASTERN VA AND NC WHERE MOST OF
THE PRECIP HAS CONTD THRU THIS MORNING AND EARLY AFTN. ANOTHER
AREA OF RAIN IS MOVG NORTH THRU EASTERN NC AND WILL AFFECT SE VA
DURING THE AFTN/EVENING PERIOD. RADAR SHOWS SOME LIGHTNING WITH
THIS ACTIVITY SO HAVE INCLUDED TSTMS IN TAFS AT ECG/ORF/PHF. HRRR
PRECIP MODEL SHOWS PRECIP AFFECTING SE VA/NE NC THRU 00Z. FRONT
WILL LIKELY REMAIN STNRY OVERNIGHT OR EVEN DISSIPATE. SFC WINDS
WILL DEPEND ON FRONT AND PRECIP BUT WILL GENERALLY BE LESS THAN 10
KT. CIGS WILL VARY BETWEEN MVFR AND VFR...BUT TEMPO IFR CONDS PSBL
WITH PRECIP. OVERNIGHT CIGS EXPECTED TO LOWER TO MVFR/IFR CONDS
WITH SOME MVFR VSBY DUE TO FOG. HI PRES EXPECTED TO GRADUALLY
BUILD INTO THE REGION ON SAT BUT SOME WIDELY SCTD SHOWERS STILL
PSBL EARLY.
&&
.MARINE...
NO HEADLINES EXPECTED THRU AT LEAST THIS WEEKEND. A FRONTAL BOUNDARY
WILL REMAIN STALLED OVER THE DELMARVA INTO SE VA THROUGH SAT BEFORE
DISSIPATING LATE IN THE DAY. WINDS WILL BE HIGHLY VARIABLE BUT LIGHT
ON THE CHES BAY THROUGH TONIGHT DUE TO THE LOCATION OF THE STALLED
FRONT. MEANWHILE...S-SE WINDS BETWEEN 10-15 KT WILL BE FOUND ON THE
COASTAL WATERS. BY SAT...THE DISSIPATING FRONT WILL ALLOW FOR S-SE
WINDS 10-15 KT ALL WATERS WITH A FEW GUSTS TO 20 KT POSSIBLE ACROSS
THE SOUTHERN COASTAL WATERS AND THE CURRITUCK SOUND. WAVES WILL
REMAIN 1-2 FT WITH SEAS 2-3 FT THROUGH SAT.
LATE SAT INTO THE MIDDLE OF NEXT WEEK...HIGH PRES WILL BUILD INTO
AND OVER THE MID-ATLANTIC REGION. THIS WILL RESULT IN GENERALLY S-SW
WINDS LESS THAN 15 KT. WAVES ON THE CHES BAY WILL CONTINUE TO
AVERAGE 1 TO 2 FT...WITH SEAS 2 TO 3 FT ON THE OCEAN.
&&
.HYDROLOGY...
SEVERAL ROUNDS OF HEAVY RAINFALL HAS RESULTED IN RAPID RISES IN
LOCAL RIVERS AND STREAMS. FLOOD WARNINGS ARE CURRENTLY IN EFFECT
FOR THE APPOMATTOX RIVER AT FARMVILLE AND MATTOAX WHERE MINOR
FLOODING IS FORECAST. HEAVY RAINFALL OVER THE UPPER JAMES BASIN
COULD PRODUCE MINOR FLOODING ALONG THE JAMES RIVER AT RICHMOND
WESTHAM DURING THE DAY SATURDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>025.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ012>017-
030>032-102.
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ077-078-
084>100.
MARINE...NONE.
&&
$$
SYNOPSIS...ESS/SAM
NEAR TERM...SAM/AJZ
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...TMG/JEF
MARINE...JDM
HYDROLOGY...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
413 PM EDT FRI JUL 12 2013
.SYNOPSIS...
COLD FRONT HAS STALLED ALONG THE COAST THIS AFTERNOON AND WILL
REMAIN OVER THE REGION THROUGH SATURDAY. HIGH PRESSURE WILL BUILD
INTO THE REGION FROM THE EAST THIS WEEKEND AS THE FRONT DISSIPATES
OVER THE AREA. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
PER LATEST MSAS ANALYSIS AND SFC OBSERVATIONS...COLD FRONT HAS
STALLED ACROSS SE VA THIS AFTERNOON. LATEST WATER VAPOR IMAGERY
CONTINUES TO SHOW PLUME OF MOISTURE LIFTING THROUGH THE REGION AS
LOW PRESSURE TO THE WEST SLOWLY DRIFTS SWD. LOW POSITION WILL
CONTINUE TO BE IN A FAVORABLE POSITION FOR STRONG UPPER LEVEL
FORCING (STRONG DIFFLUENCE ALOFT) OVER THE LOCAL AREA. SEEING
COOLING CLOUD TOPS OVER CNTRL/ERN NC ATTM AS A SHORT WAVE LIFTS
FROM THE SE. EXPECT ANOTHER WAVE OF SHOWERS AND EMBEDDED
THUNDERSTORMS TO LIFT NWD ALONG THE FRONT INTO NE NC/SE VA THROUGH
6 PM AND INTO ERN VA (MAINLY EAST OF INTERSTATE 95) THROUGH EARLY
TONIGHT. HAVE OPTED TO DROP HEADLINES OVER THE PIEDMONT AS DRY AIR
HAS WORKED IN ALOFT. LATEST RADAR TRENDS AND HRRR RUNS BACK THIS
UP WELL. HAVE ALSO EXTENDED FLASH FLOOD WATCH HEADLINES UNTIL
MIDNIGHT TONIGHT ALONG AND EAST OF INTERSTATE 95 TO ACCOUNT FOR
THE NEXT WAVE AND SATURATED SOILS. EXPECT THE WAVE TO LIFT
THROUGH THE LOCAL AREA BY MIDNIGHT...BUT SHOWERS EXPECTED TO
CONTINUE ALONG THE FRONT OVER SE VA/NE NC THROUGH LATE TONIGHT.
TEMPS EXPECTED TO FALL INTO THE UPPER 60S/LOW 70S TONIGHT UNDER
CLOUDY SKIES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
MODELS CONTINUE TO HANDLE THE MID/UPPER LEVEL PATTERN WELL
THROUGH THE SHORT TERM. THE UPPER LOW WILL BECOME CUT OFF FROM THE
FLOW TONIGHT/SAT MORNING...AS HIGH PRESSURE STRENGTHENS OVER THE
CNTRL CONUS. THE LOW IS THEN PROGGED TO UNDERCUT THE
RIDGE...PROGRESSING SWWD THROUGH THE SHORT TERM TOWARD THE SRN
PLAINS. THIS WILL ALLOW UPPER/SFC HIGH PRESSURE TO BUILD INTO THE
REGION SAT...AND REMAINING CENTERED OVER THE OH VALLEY THROUGH THE
SHORT TERM. THE RESULT OVER THE LOCAL AREA WILL BE SUMMER LIKE
CONDITIONS WITH THE STORM TRACK REMAINING WELL TO THE NORTH OF THE
REGION. MOISTURE PLUME WILL MOVE INLAND AS UPPER LEVEL FLOW
BECOMES SELY SAT...WITH BEST POPS ACROSS THE PIEDMONT SAT
AFTERNOON. WHILE FORCING FOR ASCENT WILL BE SUBTLE...DIURNAL
FORCING AND ABUNDANT MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SAT AFTERNOON...WEST OF INTERSTATE 95. WILL KEEP
MENTION OF SLIGHT CHANCE POPS FOR THE PIEDMONT SUN AFTERNOON...BUT
BEST MOISTURE/DYNAMICS LOOKS TO BE WEST OF THE AREA. AREA WILL BE
UNDER THE INFLUENCE OF HIGH PRESSURE MON...BUT DO EXPECT MOISTURE
TO ADVECT FROM THE WRN ATLANTIC INTO THE REGION. PRESENCE OF A
WEAK LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES UNDER WEAK FLOW
ALOFT...MAY RESULT IN ISOLATED-WIDELY SCATTERED THUNDERSTORMS
ACROSS THE LOCAL AREA. WILL MAINTAIN SLIGHT CHANCE POPS DURING THE
AFTERNOON FOR DIURNAL FORCING.
NEAR SEASONABLE NORMAL TEMPS SAT UNDER CLEARING SKIES FROM E TO
W. WARMING TREND WILL COMMENCE SUN AS STRONG HEIGHT RISES AND
INCREASING LOW LEVEL THICKNESS VALUES PUSH TEMPS INTO THE LOW 90S.
HOWEVER...SE FLOW WILL PREVENT TEMPS FROM REACHING THEIR FULL
POTENTIAL (HIGHS GENERALLY IN THE LOW 90S). SLIGHTLY WARMER MONDAY
AS WINDS BECOME MORE SLY (HIGHS IN THE LOW 90S). TEMPS ALONG THE
COAST DURING THE SHORT TERM WILL BE SLIGHTLY COOLER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HOTTER AND DRIER WEATHER EXPECTED NEXT WEEK...
MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG H5 RIDGE (599DM)
RESIDING OVER THE OHIO VALLEY TUESDAY/WEDNESDAY OF NEXT WEEK. THE
RIDGE THEN SLOWLY SHIFTS EAST OVER THE MID-ATLANTIC REGION THURSDAY
BEFORE MOVING EAST TO OFF THE CAROLINA COAST BY NEXT FRIDAY. THE
POSITION AND STRENGTH OF THIS RIDGE POINTS TO A SPELL OF HOT WEATHER
ACROSS THE LOCAL AREA NEXT WEEK WITH MAX TEMPS RUNNING ABOUT 1
STANDARD DEVIATION ABOVE NORMAL (MID 90S). THIS STAGNANT AIRMASS
WILL ALSO RESULT IN WARM/MUGGY NIGHTS WITH LOWS IN THE MID/UPR 70S.
LITTLE OPPORTUNITY FOR PCPN WILL OCCUR IN THIS PATTERN AS WELL
OUTSIDE OF ISOLD CONVECTION OVER THE HIGHER TERRAIN TO OUR WEST OUR
ALONG THE AFTN SEA BREEZE. WILL GO NO HIGHER THAN SLIGHT CHC (20%)
POPS THROUGH THE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A WEAK STNRY FRONT LINGERS OVER EASTERN VA AND NC WHERE MOST OF
THE PRECIP HAS CONTD THRU THIS MORNING AND EARLY AFTN. ANOTHER
AREA OF RAIN IS MOVG NORTH THRU EASTERN NC AND WILL AFFECT SE VA
DURING THE AFTN/EVENING PERIOD. RADAR SHOWS SOME LIGHTNING WITH
THIS ACTIVITY SO HAVE INCLUDED TSTMS IN TAFS AT ECG/ORF/PHF. HRRR
PRECIP MODEL SHOWS PRECIP AFFECTING SE VA/NE NC THRU 00Z. FRONT
WILL LIKELY REMAIN STNRY OVERNIGHT OR EVEN DISSIPATE. SFC WINDS
WILL DEPEND ON FRONT AND PRECIP BUT WILL GENERALLY BE LESS THAN 10
KT. CIGS WILL VARY BETWEEN MVFR AND VFR...BUT TEMPO IFR CONDS PSBL
WITH PRECIP. OVERNIGHT CIGS EXPECTED TO LOWER TO MVFR/IFR CONDS
WITH SOME MVFR VSBY DUE TO FOG. HI PRES EXPECTED TO GRADUALLY
BUILD INTO THE REGION ON SAT BUT SOME WIDELY SCTD SHOWERS STILL
PSBL EARLY.
&&
.MARINE...
NO HEADLINES EXPECTED THRU AT LEAST THIS WEEKEND. A FRONTAL BOUNDARY
WILL REMAIN STALLED OVER THE DELMARVA INTO SE VA THROUGH SAT BEFORE
DISSIPATING LATE IN THE DAY. WINDS WILL BE HIGHLY VARIABLE BUT LIGHT
ON THE CHES BAY THROUGH TONIGHT DUE TO THE LOCATION OF THE STALLED
FRONT. MEANWHILE...S-SE WINDS BETWEEN 10-15 KT WILL BE FOUND ON THE
COASTAL WATERS. BY SAT...THE DISSIPATING FRONT WILL ALLOW FOR S-SE
WINDS 10-15 KT ALL WATERS WITH A FEW GUSTS TO 20 KT POSSIBLE ACROSS
THE SOUTHERN COASTAL WATERS AND THE CURRITUCK SOUND. WAVES WILL
REMAIN 1-2 FT WITH SEAS 2-3 FT THROUGH SAT.
LATE SAT INTO THE MIDDLE OF NEXT WEEK...HIGH PRES WILL BUILD INTO
AND OVER THE MID-ATLANTIC REGION. THIS WILL RESULT IN GENERALLY S-SW
WINDS LESS THAN 15 KT. WAVES ON THE CHES BAY WILL CONTINUE TO
AVERAGE 1 TO 2 FT...WITH SEAS 2 TO 3 FT ON THE OCEAN.
&&
.HYDROLOGY...
SEVERAL ROUNDS OF HEAVY RAINFALL HAS RESULTED IN RAPID RISES IN
LOCAL RIVERS AND STREAMS. FLOOD WARNINGS ARE CURRENTLY IN EFFECT
FOR THE APPOMATTOX RIVER AT FARMVILLE AND MATTOAX WHERE MINOR
FLOODING IS FORECAST. HEAVY RAINFALL OVER THE UPPER JAMES BASIN
WILL ALSO LIKELY RESULT IN MINOR FLOODING ALONG THE JAMES RIVER AT
RICHMOND WESTHAM DURING THE DAY SATURDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>025.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ012>017-
030>032-102.
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ063-064-
070>100.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...TMG/JEF
MARINE...JDM
HYDROLOGY...SAM
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
339 AM EDT FRI JUL 12 2013
.SYNOPSIS...
A COLD FRONT HAS BECOME STATIONARY ACROSS EASTERN VIRGINIA AND IS
PROVIDING THE FOCUS FOR HEAVY RAINFALL. THIS FRONT WILL REMAIN TO THE
SOUTHEAST OF THE AREA THROUGH SATURDAY. HIGH PRESSURE WILL BUILD
INTO THE REGION NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LAST NGT/S HRRR RUNS...NAM/GFS HAD THE SOLN NAILED. SHRA/TSRA FILLED
IN...WITH COPIOUS RAFL ACRS CWFA...SPCLY IN A STRIPE FM CENTRL SHEN
VLY INTO THE WRN BURBS OF DC. THAT ACTIVITY ONGOING ATTM...W/ NMRS
FLOOD CONCERNS. SYNOPICALLY...SVRL FACTORS CONTRIBUTING TO THE
SHRA-- FIRST...HGTS HV BEEN DROPPING AS AN H5 LOW APPROACHES FM THE
GRTLKS. SECONDLY...CWFA W/IN RRQ OF AN UPR JET. ITS ONLY ABT 70
KT...BUT IT/S SUFFICIENT TO SUPPORT LIFT. THIRD...A STALLED CDFNT
WAVERING ALONG THE I-95 CORRIDOR. BELIEVE THAT THERE ARE A CPL WK
IMPULSES GLIDING ALONG THE STALLED SFC BNDRY.
THESE INGREDIENTS WL STILL BE IN PLACE TDA. IN FACT HGTS WL BE QUITE
LOW AS H5 LOW COMES VERY CLOSE TO CWFA. IN ADDITION...ELY H8 WNDS WL
INCREASE...NOT JUST LEADING TO AN OVERRUNNING SITUATION BUT ALSO
PUMPING IN ADDITIONAL ATLC MSTR. PWAT WL BE HOVERING BTWN 1.75-2.00
INCHES FOR MOST OF THE DAY.
THE BIGGEST ADJUSTMENT IN GDNC FM THE 18Z TO 00Z CYCLES IS WHETHER
THERE WL BE A PRE-DAWN BREAK IN THE ACTION. NOT ONLY THE 00Z GDNC
CYCLE...BUT ALSO THE LTST HRRR AND RADAR TRENDS SUGGEST THAT WON/T
BE HAPPENING. FURTHER...THERE/S A STRONGER SIGNAL THAT THERE WL BE A
WK LOW MVG UP THE BAY TWD MIDDAY. THEREFORE...CANT DISCERN A PART OF
THE DAY THAT WL BE DRIER THAN THE REST. WL HV DECENT LLVL CNVGNC AND
ULVL DIVGNC THRUT. IF THERE/S ONE WRINKLE...ITS THE FACT THAT SNDGS
LOOK SO SATD THAT INSTBY WL BE MINIMAL.
CONSIDERING MSTR AND FORCING...AM CONCERNED THAT FLOODING WL BE A
CONCERN. FOR SOME SPOTS /SHD TO FFX/...IT WL BE AN ONGOING ISSUE...
WHILE IT WL BE A NEW CONCERN. THEREFORE...A FLOOD WATCH WL BE
APPROPRIATE. CONSIDERING HVY RAFL RATES...WIBIS A FLASH FLOOD WATCH
FOR MOST OF CWFA TIL WRN MTNS.
HV LKLY/CAT POPS FOR ALL AREAS XPCT THE PTMC HIGHLANDS. MAXT WL BE
KEPT DOWN...SPCLY FOR THE WEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
DAYTIME ACTIVITY WL BE ONGOING INTO THE EVNG. HGTS WL START TO RISE
OVNGT. AM HOPEFUL THAT WL LEAD TO A LESSENING THREAT...AND WL TRAIL
POPS OFF OVNGT FM A PLATEAU OF LKLY. AS LONG AS THE SFC BNDRY
REMAINS...CANT COMFORTABLY REMOVE POPS FOR ANY PERIOD.
SAME BASIC CONCEPT EXTENDS INTO SAT. HGTS WL BE HIER AS H5 LOW
RETROGRADES IN RESPONSE TO BLDG RDG SFC-H5 FM WRN ATLC. HWVR...STILL
HV THE SAME FORCING MECHANISMS ON A HUMID AMS /PWATS DONT CHG TOO
MUCH/. WL HV POPS IN THE CHC CATEGORY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS HAS BEEN WRITTEN IN THE PAST TWO NGTS XTND DSCNS THE MDL
PROJECTED UPR LVL AND SFC PATTERNS FOR THE LATTER PARTS OF THE FCST
HV BEEN QUITE ANOMALOUS FOR MID JUL. REGARDLESS THE CONTINUITY BTWN
THE MDLS HAS BEEN GETTING GRTR SHOWING A SMALL UPR LVL CUTOFF LOW
OVR WEST VIRGINIA SAT TRACKING FURTHER WWD...AS HIGH PRES BUILDS OVR
NEW ENGLAND AND THEN INTO THE MID ATLC FOR MUCH OF THE NEW WK.
W/ SO MUCH MOISTURE OVR THE AREA IT IS PSBL THAT DIURNAL TSTMS
COULD DVLP SUN AFTN. AFTR THAT THE UPR RDG IS PROGGED TO COVER
MUCH OF THE ERN U.S. THRU AT LEAST MIDWEEK. TEMPS XPCTD TO CLIMB A
LTL EACH DAY...W/ HIGHS XPCTD TO GET BACK INTO THE 90S TUE THRU PSBLY
FRI. TYPICAL MID JUL WARMTH AT NGT W/ LOWS IN THE M70S IN THE
CITIES...60S W OF THE I-95.
THIS MAY NOT BE A LONG LIVED HEAT WV AS BOTH GFS AND ECMWF ARE
IMPLYING A WEAK TROF REDIGGING OVR QUEBEC/NEW ENGLAND BY NEXT FRI.
THIS WOULD LKLY BRING A CD FNT INTO THE NERN U.S. FRI. IF THIS
DOES OCCUR THE MID ALTC WL AGN HV CHCS FOR TSTMS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
NRMS-WIDESPREAD SHRA/TSRA THIS MRNG. VSBY IMPACTS WL BE LCLZD...BUT
POTENTIALY AOB IFR. DUE TO DIFFICULTIES PINPOINTING SPECIFICS IN A
TAF STYLE FCST...HV KEPT VSBYS IN MVFR. CIGS...ON THE OTHER
HAND...SHUD BE LWRG. ON TOP OF MVFR CIGS EVERYWHERE...AM TAKING
STRONG GDNC SIGNALS OF IFR FOR CHO.
FRI WL BE AN UNSETTLED DAY OVERALL. AN UPR LOW WL ROTATE TWD
AREA...SUGGESTING THAT ANY BINOVC WL ONLY QUICKLY FILL BACK IN.
FURTHER...NLY SFC FLOW AND ELY FLOW JUST OFF THE SFC WL INHIBIT MUCH
DRYING W/IN THE COLUMN. DO NOT XPCT CIGS TO RISE MUCH TAFTN. FURTHER
TSRA WL ONLY REINFORCE POTL RESTRICTIONS. CONDS CUD REALLY DROP FRI
NGT AS RAFL EXITS BUT MOIST LLVL CONDS PREVAIL.
AFTN TSTMS PSBL AT ALL AIRPORTS SUN AFTN...THEN HIGH PRES XPCTD TO
BUILD IN DURG THE FIRST PART OF THE NEW WK.
&&
.MARINE...
STALLED CDFNT WL BE NEARBY...SO WINDS VRBL AOB 10 KT. HVY RAIN IS
THE PRIMARY THREAT...BUT LCLY HIER WNDS PRESENT W/IN THESE
DOWNPOURS. WIBIS SMW/S AS APPROPRIATE.
MAY BE ABLE TO NUDGE THE FNT EWD FRI. IF SO...THERE CUD BE A SMALL
SURGE IN WNDS. STILL DO NOT HV HIGH CONFIDENCE IN THAT SCENARIO ATTM.
CONCERNS ARE THAT AN APPROACHING UPR LOW AND RIPPLES W/IN SFC FLOW
WL SUPPORT MORE SHRA/TSRA INSTEAD. AM KEEPING ALL WINDS BLO SCA
LVLS. BUT...ADDTL SMW/S MAY BE REQD.
IN THE XNTD PART OF THE FCST AFTN TSTMS WL BE PSBL ON THE WATERS
SUNDAY. OTHERWISE WINDS XPCTD TO RMN BLO SCA VALUES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR DCZ001.
MD...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MDZ003>007-009>011-
013-014-016>018.
VA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VAZ025>031-036>040-
042-050>057-501-502.
WV...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WVZ051>053.
MARINE...NONE.
&&
$$
SYNOPSIS...WOODY!
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...WOODY!
AVIATION...HTS/WOODY!
MARINE...HTS/WOODY!
AREA FORECAST DISCUSSION
NWS HASTINGS NE
123 PM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 123 PM CDT FRI JUL 12 2013
TEMPERATURES RANGING FROM 97 TO 105 DEGREES COUPLED WITH DEWPOINTS
IN THE MID 60S WILL RESULT IN HEAT INDICES TOPPING OUT BETWEEN 103
AND 106 DEGREES ACROSS PORTIONS OF NORTH CENTRAL KANSAS. A HEAT
ADVISORY WILL BE IN EFFECT THIS AFTERNOON UNTIL 7 PM THIS
EVENING FOR PHILLIPS...ROOKS...OSBORNE...AND MITCHELL COUNTIES IN
KANSAS.
UPDATE ISSUED AT 925 AM CDT FRI JUL 12 2013
THE BIG CHANGE MADE DURING THIS UPDATE WAS HIGH TEMPERATURES FOR
LATER THIS AFTERNOON. BASED ON CURRENT TRENDS...NEW DATA...AND
VERIFICATION STATISTICS...I LOWERED HIGHS THIS AFTERNOON FOR MOST
OF OUR NEBRASKA COUNTIES. THIS WAS NOT A DRASTIC CHANGE...BUT
MOST LOCATIONS WERE LOWERED TWO TO THREE DEGREES. PHILLIPS AND
ROOKS COUNTIES IN KANSAS WERE ACTUALLY RAISED A DEGREE OR
TWO...OTHERWISE...TEMPERATURES ACROSS KANSAS STAYED RELATIVELY
CLOSE TO THE PREVIOUS FORECAST. DEW POINTS WERE ALSO UPDATED TO
REFLECT TRENDS AND NEW DATA.
UPDATE ISSUED AT 635 AM CDT FRI JUL 12 2013
THE NARROW LINE OF ACCAS-INDUCED SPRINKLES/SHOWERS THAT EARLIER
STARTED TO DEVELOP WITHIN THE EASTERN FRINGES OF THE CWA HAS SINCE
ADVECTED 1+ COUNTY EAST OF OUR AREA PER THE LATEST RADAR/SATELLITE
TRENDS. THUS WILL FORGE AHEAD WITH NO PRECIP MENTION WHATSOEVER
THROUGH THE NEXT 24 HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM CDT FRI JUL 12 2013
THE PRIMARY ISSUE DURING THE NEXT 24 HOURS IS DETERMINING HOW HOT
WE ACTUALLY GET TODAY/HOW CLOSE WE GET TO HEAT ADVISORY
CRITERIA...AND HOW CLOSE TO CRITICAL FIRE DANGER WESTERN PARTS OF
NORTH CENTRAL KANSAS MIGHT GET. ALTHOUGH THE FORECAST PRODUCTS
CARRY NO MENTION OF SHOWERS/THUNDERSTORMS DUE TO POPS HOLDING BELOW
15 PERCENT...POPS ARE NOT NECESSARILY ZERO...AND WILL HAVE TO KEEP
AN EYE ESPECIALLY ON FAR WESTERN/NORTHERN COUNTIES LATE THIS
AFTERNOON-TONIGHT FOR THE REMOTE CHANCE THAT A FEW STORMS COULD
POP UP OR MOVE IN FROM THE WEST/NORTH. IN THE IMMEDIATE NEXT FEW
HOURS...ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW HIGH-
BASED SHOWERS/STORMS COULD TRY DEVELOPING IN EASTERN ZONES BEFORE
SUNRISE.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS A FAIRLY ILL-DEFINED QUASI-
STATIONARY FRONT SNAKING FROM A 1000 MILLIBAR LOW IN NORTHWEST
SD...SOUTHWARD THROUGH WESTERN NEBRASKA INTO NORTHWEST/SOUTH CENTRAL
KS. OFF TO THE EAST...A 1019MB HIGH IS CENTERED NEAR THE IA/IL
BORDER. BETWEEN THE FRONT AND THE HIGH...FAIRLY STEADY SOUTH-
SOUTHEAST BREEZES OF 8-15 MPH WITH OCCASIONAL GUSTS OVER 20 ARE IN
PLACE ACROSS THE CWA EARLY THIS MORNING...WITH THESE BREEZES
EXPECTED TO HELP HOLD LOW TEMPS UP BETWEEN 69-74 IN MOST AREAS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A
FAIRLY EXPANSIVE MID/UPPER LEVEL RIDGE AXIS THAT HAS BUILT
NORTHEAST SINCE 24 HOURS AGO TO ENCOMPASS MUCH OF THE
CENTRAL/SOUTH CENTRAL CONUS. THE CENTER AXIS OF THIS RIDGE...AT
ROUGHLY 590 DECAMETER...RUNS FROM ROUGHLY THE LOCAL CWA ON THE
NORTHEAST EDGE...BACK SOUTHWESTWARD TOWARD THE NM/TX BORDER. WITH
THIS RIDGE AXIS NEARLY OVERHEAD...THE FLOW OVER THE CWA AT 500MB
IS FAIRLY LIGHT/VARIABLE...WHILE A BIT LOWER AT 700MB...THERE IS
MODEST WEST-SOUTHWEST FLOW. A NARROW ZONE OF THETA-E ADVECTION
ALONG A FAIRLY TIGHT 700MB MOISTURE GRADIENT HAS RESULTED IN A
SCATTERED ACCAS FIELD WITHIN ROUGHLY THE EASTERN 1/3 OF THE CWA
TONIGHT...AND RECENTLY THE FIRST FEW HINTS OF ISOLATED ELEVATED
SPRINKLES/LIGHT SHOWERS HAVE SHOWED UP ON RADAR WITHIN A FEW OF
OUR EASTERN COUNTIES.
STARTING WITH THE MOST IMMEDIATE ISSUE...WILL BE CLOSELY
MONITORING RADAR TRENDS IN EASTERN ZONES PRIOR TO SUNRISE TO SEE
WHETHER THE AFOREMENTIONED VERY ISOLATED CONVECTION CAN BE COVERED
WITH A SPRINKLE MENTION...OR MIGHT NEED SOMETHING MORE.
THE LATEST RAP HAS CAUGHT ONTO THIS DEVELOPMENT...AND SUGGESTS
THAT MAINLY OUR FAR EASTERN COUNTIES NEAR THE HWY 81 CORRIDOR
COULD CONTINUE TO SEE SOME OF THIS PRE-DAWN ACTIVITY...BUT THAT IT
SHOULD LARGELY BE DONE OR ADVECTED EAST OF THE CWA BY 7AM/12Z. PER
FORECAST SOUNDINGS...PARCELS ROOTED NEAR 700MB COULD POTENTIALLY
HAVE UP TO AROUND 400 J/KG MUCAPE AVAILABLE TO THEM...SO A BRIEF
FLARE UP OF NON-SEVERE THUNDERSTORMS IS NOT COMPLETELY OUT OF THE
QUESTION. FOR NOW...WILL ONLY MENTION ISOLATED SPRINKLES IN OUR
EASTERN FEW COLUMNS OF NEBRASKA COUNTIES THROUGH 12Z TO COVER
THINGS...PENDING ANY EVIDENCE OTHERWISE.
TURNING TO THE DAYTIME HOURS...THE MAIN STORY WILL BE A RETURN OF
LEGITIMATE SUMMER HEAT...BUT DOES NOT APPEAR TO BE HEADLINE-
WORTHY. IN THE MID/UPPER LEVELS...THE DOMINANT RIDGE AXIS WILL
CONTINUE TO EXPAND ACROSS THE CENTRAL PLAINS IN A SOUTHWEST-
NORTHEAST FASHION...WITH PARTS OF THE CWA ALIGNED ALMOST DIRECTLY
UNDER ITS CENTER AXIS. AT THE SURFACE...A FAIRLY SHARP TROUGH
AXIS WILL SET UP FROM FAR EASTERN CO ACROSS NORTHWEST NEB INTO
CENTRAL SD BY MID-LATE AFTERNOON...EXTENDING FROM A ROUGHLY 1000MB
LOW CENTERED NEAR THE CO/KS BORDER. THE LOCAL CWA WILL REMAIN IN
THE OPEN WARM SECTOR SOLIDLY SOUTHEAST OF THIS TROUGH AXIS...AND
THUS WILL SEE A CONTINUATION OF FAIRLY BREEZY SOUTH-SOUTHEAST
WINDS...WITH SUSTAINED SPEEDS MOST ALL AREAS 15-20 MPH AND GUSTS
25 TO POSSIBLY 30 MPH AT TIMES. AS FOR CONVECTIVE CHANCES...ASIDE
FROM ANY EARLY MORNING ACTIVITY IN THE EAST...THERE IS LITTLE IF
ANY RISK OF SHOWERS/STORMS TODAY AS WARM MID LEVEL TEMPS WITHIN
THE RIDGE AXIS SHOULD SERVE TO CAP THINGS OFF PRETTY SOLIDLY. ONE
OF THE ONLY POSSIBLE CAVEATS...AS DEPICTED BY THE LATEST RAP
RUNS...IS THAT STRONG HEATING AND VERY DEEP MIXING COULD POP A FEW
HIGH-BASED STORMS LATE IN THE AFTERNOON ALONG WESTERN PORTIONS OF
THE NEB/KS BORDER...WITH SOME OF THIS ACTIVITY POSSIBLY ADVECTING
EAST INTO THE DAWSON-FURNAS COUNTY CORRIDOR...BUT THE ODDS OF THIS
SEEM LOW ENOUGH TO STICK WITH SILENT 10 POPS FOR NOW...AS MOST
LATE AFTERNOON STORMS SHOULD FOCUS WELL TO OUR NORTHWEST ALONG THE
AFOREMENTIONED TROUGH AXIS. TEMP-WISE...BASED ON HOW HIGHS TURNED
OUT YESTERDAY...IT APPEARS THE NAM AND ASSOCIATED MET GUIDANCE HAS
BEEN A BIT AGGRESSIVE WITH THE HEAT...AND AS A RESULT...HAVE
SHAVED A FEW DEGREES OFF HIGHS TODAY IN MOST AREAS...USING VALUES
A BIT CLOSER TO GFS MAV GUIDANCE AND A MULTI-MODEL BLEND. THIS STILL
YIELDS A VERY TOASTY DAY WITH HIGHS RANGING FROM MID 90S NORTHEAST
...MID-UPPER 90S CENTRAL AND UPPER 90S TO AROUND 102 IN KS ZONES
AND NEAR THE STATE LINE. AS FOR DEWPOINTS...NOT EXPECTING A
DRAMATIC MIX-DOWN TODAY GIVEN THAT WINDS WILL BE MORE SOUTHERLY
VERSUS SOUTHWESTERLY...BUT NUDGED THEM DOWN A BIT ESPECIALLY IN
WESTERN ZONES...RANGING FROM UPPER 50S AT MID-AFTERNOON IN THE FAR
WEST TO MID-UPPER 60S IN THE EAST. THE RESULTANT HEAT INDEX VALUES
PEAK IN THE 98-100 RANGE ACROSS MOST OF THE NEB CWA...WITH KS
ZONES AND AREAS NEAR THE STATE LINE MORE LIKELY TO REACH THE
101-104 RANGE. BOTTOM LINE HERE IS...THESE VALUES ARE CERTAINLY
WORTH A HAZARDOUS WEATHER OUTLOOK MENTION...BUT DO NOT JUSTIFY A
FORMAL HEAT ADVISORY BASED ON OUR 105+ LOCAL CRITERIA. PLEASE NOTE
THAT THE NORTH PLATTE/LBF CWA HAS A SLIGHTLY COOLER
...CLIMATOLOGICALLY-BASED HEAT ADVISORY CRITERIA OF 100+...AND
THIS IS WHY A FORMAL HEADLINE IS OUT FOR THEIR AREA...BUT NOT FOR
OURS.
TURNING TO THIS EVENING/TONIGHT POST-7PM/00Z...THE MAIN STORY
VERSUS PREVIOUS FORECAST IS THAT THE SLIGHT CHANCE OF
THUNDERSTORMS HAS BEEN TRIMMED FROM THE EXTREME NORTHERN/WEST-
CENTRAL EDGES OF THE CWA...AND THUS WILL CARRY A STORM-FREE
FORECAST CWA-WIDE. AGAIN THOUGH...WILL EMPHASIZE THAT SILENT 10
POPS WILL REMAIN IN PLACE ESPECIALLY IN NORTHERN/WESTERN COUNTIES
TO AT LEAST ACKNOWLEDGE THAT A VERY LOW PROBABILITY OF SOME
ACTIVITY IS NOT COMPLETELY OUT OF THE QUESTION. IN THE MID-UPPER
LEVELS...THERE IS VERY LITTLE CHANGE WITH THE STRENGTH/ORIENTATION
OF THE EXPANSIVE RIDGE AXIS...AS IT REMAINS DRAPED FROM SOUTHWEST-
NORTHEAST ACROSS THE HEART OF THE CENTRAL PLAINS. A BIT LOWER AT
850MB...A 40+KT SOUTHERLY LOW LEVEL JET CRANKS UP THROUGH THE
NIGHT FROM WESTERN KS ACROSS CENTRAL NEB INTO EASTERN SD/WESTERN
MN...HELPING TO FOCUS THE VAST MAJORITY OF REGIONAL CONVECTION
NEAR THE EXIT REGION OF THIS FEATURE FROM NORTHEAST CO ACROSS
NORTHWEST NEB INTO SD/MN. AT THE SURFACE...THERE WILL ALSO BE
LITTLE OVERALL CHANGE FROM THE DAYTIME HOURS...WITH THE TROUGH
AXIS PERSISTING FROM NEAR THE KS/CO BORDER NORTH-NORTHEAST INTO
CENTRAL SD. WITH A CONTINUED MODEST PRESSURE GRADIENT AND LIMITED
MIXING UNDER THE LOW LEVEL JET...SURFACE BREEZES ACROSS THE CWA
WILL AGAIN AVERAGE 10-15 MPH FROM THE SOUTH-SOUTHEAST. ASSUMING
THAT POTENTIALLY ROGUE LATE AFTERNOON/EARLY EVENING STORMS DO NOT
AFFECT THE FAR WESTERN CWA...ITS PRETTY APPARENT FROM MOST MODEL
DEPICTIONS THAT OVERNIGHT CONVECTION SHOULD FOCUS AT LEAST 50-100
MILES NORTH THROUGH NORTHWEST OF THE CWA...AND GENERALLY LIFT
NORTH WITH TIME. THE ONLY FORESEEABLE CAVEAT HERE WOULD BE IF
NORTHERN NEB STORMS DEVELOP A COLD POOL AND START TO BUILD
SOUTHWARD INTO THE LOW LEVEL JET AXIS...POTENTIALLY REACHING THE
NORTHERN PARTS OF THE CWA. INTERESTINGLY...AT LEAST ONE
MODEL...THE 4KM WRF-NMM FROM PSU...DOES DEPICT THIS SCENARIO...BUT
GIVEN SUCH LIMITED SUPPORT WILL KEEP IT STORM-FREE FOR NOW. WILL
ALSO NOTE THAT THE 00Z GFS DEPICTION OF LATE NIGHT STORMS FLARING
UP NEAR HIGHWAY 81...LIKELY IN RESPONSE TO ANOTHER SUBTLE BATCH OF
MID LEVEL THETA-E ADVECTION...HAS BEEN DISREGARDED AS AN OUTLIER
AS WELL FOR THIS FORECAST. LOW TEMPERATURES WERE CHANGED
LITTLE...AND AGAIN REFLECT A SLIGHT UPWARD TREND FROM THE PAST FEW
NIGHTS...WITH MOST AREAS PROGGED TO BOTTOM OUT 72-75.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 431 AM CDT FRI JUL 12 2013
FOCUS FOR THIS TIMEFRAME WILL INVOLVE BOTH HIGH TEMPERATURES AND
PRECIPITATION CHANCES. MOST OF THE OPERATIONAL MODELS ARE COMING
INTO AGREEMENT ON THE UNUSUAL PATTERN EXPECTED IN THE SATURDAY TO
THURSDAY PERIOD. THEY ARE TAKING THE MID/UPPER LEVEL LOW PRESSURE
CURRENTLY SITTING OVER OHIO...AND RETROGRADING IT BACK TO THE
WEST. BY 12Z SAT THE GFS HAS IT OVER CENTRAL TENN...WHILE THE EC
PLACES IT A LITTLE NORTH OF THERE OVER KENTUCKY...AND THE NAM IS
BETWEEN THE TWO. BY 12Z SUNDAY THESE MODELS HAVE IT FROM CENTRAL
MISSOURI TO WESTERN ARKANSAS. THIS WESTWARD PUSH IS PROGGED TO
CONTINUE AND BY 12Z MONDAY IT IS FORECAST TO BE FROM NORTHERN
OKLAHOMA TO NORTHERN TEXAS. IT THEN APPEARS TO REMAIN OVER THE
TEXAS PANHANDLE OR IN NORTHEASTERN NEW MEXICO WHILE GRADUALLY
FILLING INTO THE WORKWEEK.
THIS IS NOT A VERY COMMON SCENARIO AND IF IT DOES COME TO FRUITION
WOULD MEAN COOLER TEMPERATURES STARTING SUNDAY. IN THE PAST 24
HRS...THE EXPECTED 850 MB TEMPS FOR SUNDAY OVER OUR AREA HAVE
DECREASED ABOUT 8-10 DEGREES C. GIVEN THE CONSISTENCY OF THE VARIOUS
OPERATIONAL MODELS WILL BUY INTO THIS SCENARIO AND LOWER HIGHS ON
SUNDAY BY SEVERAL DEGREES. SIMILAR TEMPERATURES CAN BE EXPECTED ON
MONDAY AND TUESDAY. WHILE COOLER THAN THOSE EXPECTED FOR TODAY AND
SATURDAY...WOULD NOT EXACTLY CALL IT COOL WEATHER AS HIGHS WILL
ACTUALLY BE AROUND NORMAL FOR THIS TIME OF YEAR FOR SUN-TUES. AFTER
THAT WE SHOULD SEE A GRADUAL WARMUP AS RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION.
PRECIPITATION CONTINUES TO BE DIFFICULT TO FORECAST. LOOKS LIKE
THERE ARE AT LEAST SLIGHT CHANCES ON SAT AND SUNDAY NIGHTS OVER MUCH
OF THE CWA WITH A SURFACE BOUNDARY JUST TO OUR WEST...WEAK WAVES
ROTATING JUST TO OUR NORTH ALONG THE NORTHERN JET...AND THE
APPROACHING RETROGRADING LOW MENTIONED ABOVE. WILL CONTINUE TO
FORECAST DRY WEATHER FOR THE UPCOMING WORKWEEK BUT THAT MAY CHANGE
DEPENDING HOW FAR NORTH THAT RETROGRADING LOW TRACKS. AT
PRESENT...IT MAY AFFECT THE KANSAS PART OF OUR CWA BUT THE FURTHER
NORTH ITS TRACK...THE BETTER THE CHANCE FOR SOME RAIN IN THE NEB
PART OF OUR CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 123 PM CDT FRI JUL 12 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE VALID TAF PERIOD AT KGRI.
AN UPPER LEVEL RIDGE WILL CONTINUE TO SIT OVER THE REGION AND
SHOULD PROVIDE MOSTLY CLEAR SKIES FOR THE TERMINAL. THE WIND
DIRECTION WILL REMAIN FAIRLY CONSTANT WITH A SOUTHERLY COMPONENT
THROUGH THIS PERIOD. WIND SPEEDS WILL REMAIN RATHER CONSISTENT AS
WELL. THE MAIN CONCERN OVER THE TAF PERIOD WILL BE THE LOW LEVEL
WIND SHEAR TONIGHT. THIS WILL BE MOSTLY A SPEED SHEAR TYPE OF
EVENT BUT SOME DIRECTIONAL SHEAR WILL BE NOTICED AS WELL ONCE THE
LOW LEVEL JET KICKS UP TONIGHT. A 30+KT DIFFERENCE IN WIND SPEED
FROM THE SURFACE TO 1500 WILL BE EXPERINCED TONIGHT. THE WIND
DIRECTION AT 1500 FT WILL BE OUT OF THE SOUTHWEST.
&&
.FIRE WEATHER...
ISSUED AT 431 AM CDT FRI JUL 12 2013
ALTHOUGH CRITICAL FIRE WEATHER CONDITIONS/DANGER ARE NOT
ANTICIPATED WITHIN THE CWA TODAY...NEAR-CRITICAL CONDITIONS ARE
FORECAST ESPECIALLY IN THE FAR SOUTHWEST IN THE PHILLIPS/ROOKS
COUNTY AREAS...AND THUS WILL INTRODUCE THIS MENTION INTO THE
HAZARDOUS WEATHER OUTLOOK. THIS AREA WILL FEATURE THE GREATEST
OVERLAP OF SUSTAINED WINDS/GUSTS 20/25 MPH...AND RELATIVE HUMIDITY
VALUES NEAR OR SLIGHTLY BELOW 25 PERCENT. CERTAINLY...AT LEAST A
LIMITED FIRE DANGER WILL EXIST ELSEWHERE ACROSS THE CWA GIVEN THE
STEADY BREEZES AND OVERALL DRY CONDITIONS OF LATE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ005-017>019.
&&
$$
UPDATE...GUERRERO
SHORT TERM...PFANNKUCH
LONG TERM...EWALD
AVIATION...GUERRERO
FIRE WEATHER...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
925 AM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 925 AM CDT FRI JUL 12 2013
THE BIG CHANGE MADE DURING THIS UPDATE WAS HIGH TEMPERATURES FOR
LATER THIS AFTERNOON. BASED ON CURRENT TRENDS...NEW DATA...AND
VERIFICATION STATISTICS...I LOWERED HIGHS THIS AFTERNOON FOR MOST
OF OUR NEBRASKA COUNTIES. THIS WAS NOT A DRASTIC CHANGE...BUT
MOST LOCATIONS WERE LOWERED TWO TO THREE DEGREES. PHILLIPS AND
ROOKS COUNTIES IN KANSAS WERE ACTUALLY RAISED A DEGREE OR
TWO...OTHERWISE...TEMPERATURES ACROSS KANSAS STAYED RELATIVELY
CLOSE TO THE PREVIOUS FORECAST. DEW POINTS WERE ALSO UPDATED TO
REFLECT TRENDS AND NEW DATA.
UPDATE ISSUED AT 635 AM CDT FRI JUL 12 2013
THE NARROW LINE OF ACCAS-INDUCED SPRINKLES/SHOWERS THAT EARLIER
STARTED TO DEVELOP WITHIN THE EASTERN FRINGES OF THE CWA HAS SINCE
ADVECTED 1+ COUNTY EAST OF OUR AREA PER THE LATEST RADAR/SATELLITE
TRENDS. THUS WILL FORGE AHEAD WITH NO PRECIP MENTION WHATSOEVER
THROUGH THE NEXT 24 HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM CDT FRI JUL 12 2013
THE PRIMARY ISSUE DURING THE NEXT 24 HOURS IS DETERMINING HOW HOT
WE ACTUALLY GET TODAY/HOW CLOSE WE GET TO HEAT ADVISORY
CRITERIA...AND HOW CLOSE TO CRITICAL FIRE DANGER WESTERN PARTS OF
NORTH CENTRAL KANSAS MIGHT GET. ALTHOUGH THE FORECAST PRODUCTS
CARRY NO MENTION OF SHOWERS/THUNDERSTORMS DUE TO POPS HOLDING BELOW
15 PERCENT...POPS ARE NOT NECESSARILY ZERO...AND WILL HAVE TO KEEP
AN EYE ESPECIALLY ON FAR WESTERN/NORTHERN COUNTIES LATE THIS
AFTERNOON-TONIGHT FOR THE REMOTE CHANCE THAT A FEW STORMS COULD
POP UP OR MOVE IN FROM THE WEST/NORTH. IN THE IMMEDIATE NEXT FEW
HOURS...ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW HIGH-
BASED SHOWERS/STORMS COULD TRY DEVELOPING IN EASTERN ZONES BEFORE
SUNRISE.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS A FAIRLY ILL-DEFINED QUASI-
STATIONARY FRONT SNAKING FROM A 1000 MILLIBAR LOW IN NORTHWEST
SD...SOUTHWARD THROUGH WESTERN NEBRASKA INTO NORTHWEST/SOUTH CENTRAL
KS. OFF TO THE EAST...A 1019MB HIGH IS CENTERED NEAR THE IA/IL
BORDER. BETWEEN THE FRONT AND THE HIGH...FAIRLY STEADY SOUTH-
SOUTHEAST BREEZES OF 8-15 MPH WITH OCCASIONAL GUSTS OVER 20 ARE IN
PLACE ACROSS THE CWA EARLY THIS MORNING...WITH THESE BREEZES
EXPECTED TO HELP HOLD LOW TEMPS UP BETWEEN 69-74 IN MOST AREAS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A
FAIRLY EXPANSIVE MID/UPPER LEVEL RIDGE AXIS THAT HAS BUILT
NORTHEAST SINCE 24 HOURS AGO TO ENCOMPASS MUCH OF THE
CENTRAL/SOUTH CENTRAL CONUS. THE CENTER AXIS OF THIS RIDGE...AT
ROUGHLY 590 DECAMETER...RUNS FROM ROUGHLY THE LOCAL CWA ON THE
NORTHEAST EDGE...BACK SOUTHWESTWARD TOWARD THE NM/TX BORDER. WITH
THIS RIDGE AXIS NEARLY OVERHEAD...THE FLOW OVER THE CWA AT 500MB
IS FAIRLY LIGHT/VARIABLE...WHILE A BIT LOWER AT 700MB...THERE IS
MODEST WEST-SOUTHWEST FLOW. A NARROW ZONE OF THETA-E ADVECTION
ALONG A FAIRLY TIGHT 700MB MOISTURE GRADIENT HAS RESULTED IN A
SCATTERED ACCAS FIELD WITHIN ROUGHLY THE EASTERN 1/3 OF THE CWA
TONIGHT...AND RECENTLY THE FIRST FEW HINTS OF ISOLATED ELEVATED
SPRINKLES/LIGHT SHOWERS HAVE SHOWED UP ON RADAR WITHIN A FEW OF
OUR EASTERN COUNTIES.
STARTING WITH THE MOST IMMEDIATE ISSUE...WILL BE CLOSELY
MONITORING RADAR TRENDS IN EASTERN ZONES PRIOR TO SUNRISE TO SEE
WHETHER THE AFOREMENTIONED VERY ISOLATED CONVECTION CAN BE COVERED
WITH A SPRINKLE MENTION...OR MIGHT NEED SOMETHING MORE.
THE LATEST RAP HAS CAUGHT ONTO THIS DEVELOPMENT...AND SUGGESTS
THAT MAINLY OUR FAR EASTERN COUNTIES NEAR THE HWY 81 CORRIDOR
COULD CONTINUE TO SEE SOME OF THIS PRE-DAWN ACTIVITY...BUT THAT IT
SHOULD LARGELY BE DONE OR ADVECTED EAST OF THE CWA BY 7AM/12Z. PER
FORECAST SOUNDINGS...PARCELS ROOTED NEAR 700MB COULD POTENTIALLY
HAVE UP TO AROUND 400 J/KG MUCAPE AVAILABLE TO THEM...SO A BRIEF
FLARE UP OF NON-SEVERE THUNDERSTORMS IS NOT COMPLETELY OUT OF THE
QUESTION. FOR NOW...WILL ONLY MENTION ISOLATED SPRINKLES IN OUR
EASTERN FEW COLUMNS OF NEBRASKA COUNTIES THROUGH 12Z TO COVER
THINGS...PENDING ANY EVIDENCE OTHERWISE.
TURNING TO THE DAYTIME HOURS...THE MAIN STORY WILL BE A RETURN OF
LEGITIMATE SUMMER HEAT...BUT DOES NOT APPEAR TO BE HEADLINE-
WORTHY. IN THE MID/UPPER LEVELS...THE DOMINANT RIDGE AXIS WILL
CONTINUE TO EXPAND ACROSS THE CENTRAL PLAINS IN A SOUTHWEST-
NORTHEAST FASHION...WITH PARTS OF THE CWA ALIGNED ALMOST DIRECTLY
UNDER ITS CENTER AXIS. AT THE SURFACE...A FAIRLY SHARP TROUGH
AXIS WILL SET UP FROM FAR EASTERN CO ACROSS NORTHWEST NEB INTO
CENTRAL SD BY MID-LATE AFTERNOON...EXTENDING FROM A ROUGHLY 1000MB
LOW CENTERED NEAR THE CO/KS BORDER. THE LOCAL CWA WILL REMAIN IN
THE OPEN WARM SECTOR SOLIDLY SOUTHEAST OF THIS TROUGH AXIS...AND
THUS WILL SEE A CONTINUATION OF FAIRLY BREEZY SOUTH-SOUTHEAST
WINDS...WITH SUSTAINED SPEEDS MOST ALL AREAS 15-20 MPH AND GUSTS
25 TO POSSIBLY 30 MPH AT TIMES. AS FOR CONVECTIVE CHANCES...ASIDE
FROM ANY EARLY MORNING ACTIVITY IN THE EAST...THERE IS LITTLE IF
ANY RISK OF SHOWERS/STORMS TODAY AS WARM MID LEVEL TEMPS WITHIN
THE RIDGE AXIS SHOULD SERVE TO CAP THINGS OFF PRETTY SOLIDLY. ONE
OF THE ONLY POSSIBLE CAVEATS...AS DEPICTED BY THE LATEST RAP
RUNS...IS THAT STRONG HEATING AND VERY DEEP MIXING COULD POP A FEW
HIGH-BASED STORMS LATE IN THE AFTERNOON ALONG WESTERN PORTIONS OF
THE NEB/KS BORDER...WITH SOME OF THIS ACTIVITY POSSIBLY ADVECTING
EAST INTO THE DAWSON-FURNAS COUNTY CORRIDOR...BUT THE ODDS OF THIS
SEEM LOW ENOUGH TO STICK WITH SILENT 10 POPS FOR NOW...AS MOST
LATE AFTERNOON STORMS SHOULD FOCUS WELL TO OUR NORTHWEST ALONG THE
AFOREMENTIONED TROUGH AXIS. TEMP-WISE...BASED ON HOW HIGHS TURNED
OUT YESTERDAY...IT APPEARS THE NAM AND ASSOCIATED MET GUIDANCE HAS
BEEN A BIT AGGRESSIVE WITH THE HEAT...AND AS A RESULT...HAVE
SHAVED A FEW DEGREES OFF HIGHS TODAY IN MOST AREAS...USING VALUES
A BIT CLOSER TO GFS MAV GUIDANCE AND A MULTI-MODEL BLEND. THIS STILL
YIELDS A VERY TOASTY DAY WITH HIGHS RANGING FROM MID 90S NORTHEAST
...MID-UPPER 90S CENTRAL AND UPPER 90S TO AROUND 102 IN KS ZONES
AND NEAR THE STATE LINE. AS FOR DEWPOINTS...NOT EXPECTING A
DRAMATIC MIX-DOWN TODAY GIVEN THAT WINDS WILL BE MORE SOUTHERLY
VERSUS SOUTHWESTERLY...BUT NUDGED THEM DOWN A BIT ESPECIALLY IN
WESTERN ZONES...RANGING FROM UPPER 50S AT MID-AFTERNOON IN THE FAR
WEST TO MID-UPPER 60S IN THE EAST. THE RESULTANT HEAT INDEX VALUES
PEAK IN THE 98-100 RANGE ACROSS MOST OF THE NEB CWA...WITH KS
ZONES AND AREAS NEAR THE STATE LINE MORE LIKELY TO REACH THE
101-104 RANGE. BOTTOM LINE HERE IS...THESE VALUES ARE CERTAINLY
WORTH A HAZARDOUS WEATHER OUTLOOK MENTION...BUT DO NOT JUSTIFY A
FORMAL HEAT ADVISORY BASED ON OUR 105+ LOCAL CRITERIA. PLEASE NOTE
THAT THE NORTH PLATTE/LBF CWA HAS A SLIGHTLY COOLER
...CLIMATOLOGICALLY-BASED HEAT ADVISORY CRITERIA OF 100+...AND
THIS IS WHY A FORMAL HEADLINE IS OUT FOR THEIR AREA...BUT NOT FOR
OURS.
TURNING TO THIS EVENING/TONIGHT POST-7PM/00Z...THE MAIN STORY
VERSUS PREVIOUS FORECAST IS THAT THE SLIGHT CHANCE OF
THUNDERSTORMS HAS BEEN TRIMMED FROM THE EXTREME NORTHERN/WEST-
CENTRAL EDGES OF THE CWA...AND THUS WILL CARRY A STORM-FREE
FORECAST CWA-WIDE. AGAIN THOUGH...WILL EMPHASIZE THAT SILENT 10
POPS WILL REMAIN IN PLACE ESPECIALLY IN NORTHERN/WESTERN COUNTIES
TO AT LEAST ACKNOWLEDGE THAT A VERY LOW PROBABILITY OF SOME
ACTIVITY IS NOT COMPLETELY OUT OF THE QUESTION. IN THE MID-UPPER
LEVELS...THERE IS VERY LITTLE CHANGE WITH THE STRENGTH/ORIENTATION
OF THE EXPANSIVE RIDGE AXIS...AS IT REMAINS DRAPED FROM SOUTHWEST-
NORTHEAST ACROSS THE HEART OF THE CENTRAL PLAINS. A BIT LOWER AT
850MB...A 40+KT SOUTHERLY LOW LEVEL JET CRANKS UP THROUGH THE
NIGHT FROM WESTERN KS ACROSS CENTRAL NEB INTO EASTERN SD/WESTERN
MN...HELPING TO FOCUS THE VAST MAJORITY OF REGIONAL CONVECTION
NEAR THE EXIT REGION OF THIS FEATURE FROM NORTHEAST CO ACROSS
NORTHWEST NEB INTO SD/MN. AT THE SURFACE...THERE WILL ALSO BE
LITTLE OVERALL CHANGE FROM THE DAYTIME HOURS...WITH THE TROUGH
AXIS PERSISTING FROM NEAR THE KS/CO BORDER NORTH-NORTHEAST INTO
CENTRAL SD. WITH A CONTINUED MODEST PRESSURE GRADIENT AND LIMITED
MIXING UNDER THE LOW LEVEL JET...SURFACE BREEZES ACROSS THE CWA
WILL AGAIN AVERAGE 10-15 MPH FROM THE SOUTH-SOUTHEAST. ASSUMING
THAT POTENTIALLY ROGUE LATE AFTERNOON/EARLY EVENING STORMS DO NOT
AFFECT THE FAR WESTERN CWA...ITS PRETTY APPARENT FROM MOST MODEL
DEPICTIONS THAT OVERNIGHT CONVECTION SHOULD FOCUS AT LEAST 50-100
MILES NORTH THROUGH NORTHWEST OF THE CWA...AND GENERALLY LIFT
NORTH WITH TIME. THE ONLY FORESEEABLE CAVEAT HERE WOULD BE IF
NORTHERN NEB STORMS DEVELOP A COLD POOL AND START TO BUILD
SOUTHWARD INTO THE LOW LEVEL JET AXIS...POTENTIALLY REACHING THE
NORTHERN PARTS OF THE CWA. INTERESTINGLY...AT LEAST ONE
MODEL...THE 4KM WRF-NMM FROM PSU...DOES DEPICT THIS SCENARIO...BUT
GIVEN SUCH LIMITED SUPPORT WILL KEEP IT STORM-FREE FOR NOW. WILL
ALSO NOTE THAT THE 00Z GFS DEPICTION OF LATE NIGHT STORMS FLARING
UP NEAR HIGHWAY 81...LIKELY IN RESPONSE TO ANOTHER SUBTLE BATCH OF
MID LEVEL THETA-E ADVECTION...HAS BEEN DISREGARDED AS AN OUTLIER
AS WELL FOR THIS FORECAST. LOW TEMPERATURES WERE CHANGED
LITTLE...AND AGAIN REFLECT A SLIGHT UPWARD TREND FROM THE PAST FEW
NIGHTS...WITH MOST AREAS PROGGED TO BOTTOM OUT 72-75.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 431 AM CDT FRI JUL 12 2013
FOCUS FOR THIS TIMEFRAME WILL INVOLVE BOTH HIGH TEMPERATURES AND
PRECIPITATION CHANCES. MOST OF THE OPERATIONAL MODELS ARE COMING
INTO AGREEMENT ON THE UNUSUAL PATTERN EXPECTED IN THE SATURDAY TO
THURSDAY PERIOD. THEY ARE TAKING THE MID/UPPER LEVEL LOW PRESSURE
CURRENTLY SITTING OVER OHIO...AND RETROGRADING IT BACK TO THE
WEST. BY 12Z SAT THE GFS HAS IT OVER CENTRAL TENN...WHILE THE EC
PLACES IT A LITTLE NORTH OF THERE OVER KENTUCKY...AND THE NAM IS
BETWEEN THE TWO. BY 12Z SUNDAY THESE MODELS HAVE IT FROM CENTRAL
MISSOURI TO WESTERN ARKANSAS. THIS WESTWARD PUSH IS PROGGED TO
CONTINUE AND BY 12Z MONDAY IT IS FORECAST TO BE FROM NORTHERN
OKLAHOMA TO NORTHERN TEXAS. IT THEN APPEARS TO REMAIN OVER THE
TEXAS PANHANDLE OR IN NORTHEASTERN NEW MEXICO WHILE GRADUALLY
FILLING INTO THE WORKWEEK.
THIS IS NOT A VERY COMMON SCENARIO AND IF IT DOES COME TO FRUITION
WOULD MEAN COOLER TEMPERATURES STARTING SUNDAY. IN THE PAST 24
HRS...THE EXPECTED 850 MB TEMPS FOR SUNDAY OVER OUR AREA HAVE
DECREASED ABOUT 8-10 DEGREES C. GIVEN THE CONSISTENCY OF THE VARIOUS
OPERATIONAL MODELS WILL BUY INTO THIS SCENARIO AND LOWER HIGHS ON
SUNDAY BY SEVERAL DEGREES. SIMILAR TEMPERATURES CAN BE EXPECTED ON
MONDAY AND TUESDAY. WHILE COOLER THAN THOSE EXPECTED FOR TODAY AND
SATURDAY...WOULD NOT EXACTLY CALL IT COOL WEATHER AS HIGHS WILL
ACTUALLY BE AROUND NORMAL FOR THIS TIME OF YEAR FOR SUN-TUES. AFTER
THAT WE SHOULD SEE A GRADUAL WARMUP AS RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION.
PRECIPITATION CONTINUES TO BE DIFFICULT TO FORECAST. LOOKS LIKE
THERE ARE AT LEAST SLIGHT CHANCES ON SAT AND SUNDAY NIGHTS OVER MUCH
OF THE CWA WITH A SURFACE BOUNDARY JUST TO OUR WEST...WEAK WAVES
ROTATING JUST TO OUR NORTH ALONG THE NORTHERN JET...AND THE
APPROACHING RETROGRADING LOW MENTIONED ABOVE. WILL CONTINUE TO
FORECAST DRY WEATHER FOR THE UPCOMING WORKWEEK BUT THAT MAY CHANGE
DEPENDING HOW FAR NORTH THAT RETROGRADING LOW TRACKS. AT
PRESENT...IT MAY AFFECT THE KANSAS PART OF OUR CWA BUT THE FURTHER
NORTH ITS TRACK...THE BETTER THE CHANCE FOR SOME RAIN IN THE NEB
PART OF OUR CWA.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM CDT FRI JUL 12 2013
THERE IS FAIRLY HIGH CONFIDENCE THAT VFR CEILING/VISIBILITY WILL
PREVAIL THROUGH THE PERIOD...WITH MID/UPPER LEVEL HIGH PRESSURE
DOMINATING THE LOCAL WEATHER PATTERN AND PROVIDING MOSTLY CLEAR
SKIES...AND VERY LITTLE IF ANY RISK OF A SHOWER/THUNDERSTORM. AS
FOR SURFACE WINDS...A RATHER CONSTANT SOUTH-SOUTHEAST DIRECTION
WILL PREVAIL THROUGHOUT THE PERIOD...AND IT WILL REMAIN FAIRLY
BREEZY MOST OF THE TIME...WITH GUSTS COMMONLY UP TO AROUND
18KT...AND DAYTIME GUST POTENTIAL TO AT LEAST 25KT. THE ONLY REAL
ISSUE OF NOTE IS LOW LEVEL WIND SHEAR UNDERNEATH A NOCTURNAL LOW
LEVEL JET. WILL CONTINUE A MENTION OF MARGINAL LLWS FOR THE FIRST
FEW HOURS THIS MORNING...AND THEN BRING BACK ANOTHER ROUND OF LLWS
FOR THE EARLY SATURDAY MORNING HOURS THANKS TO A SIMILAR
SETUP...WITH 30+KT OF BULK SHEAR DIFFERENCE BETWEEN THE SURFACE
AND APPROXIMATELY 1500 FT AGL...WHERE SUSTAINED SOUTH-SOUTHWEST
WINDS UP TO AROUND 43KT WILL DEVELOP.
&&
.FIRE WEATHER...
ISSUED AT 431 AM CDT FRI JUL 12 2013
ALTHOUGH CRITICAL FIRE WEATHER CONDITIONS/DANGER ARE NOT
ANTICIPATED WITHIN THE CWA TODAY...NEAR-CRITICAL CONDITIONS ARE
FORECAST ESPECIALLY IN THE FAR SOUTHWEST IN THE PHILLIPS/ROOKS
COUNTY AREAS...AND THUS WILL INTRODUCE THIS MENTION INTO THE
HAZARDOUS WEATHER OUTLOOK. THIS AREA WILL FEATURE THE GREATEST
OVERLAP OF SUSTAINED WINDS/GUSTS 20/25 MPH...AND RELATIVE HUMIDITY
VALUES NEAR OR SLIGHTLY BELOW 25 PERCENT. CERTAINLY...AT LEAST A
LIMITED FIRE DANGER WILL EXIST ELSEWHERE ACROSS THE CWA GIVEN THE
STEADY BREEZES AND OVERALL DRY CONDITIONS OF LATE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...GUERRERO
SHORT TERM...PFANNKUCH
LONG TERM...EWALD
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
638 AM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 635 AM CDT FRI JUL 12 2013
THE NARROW LINE OF ACCAS-INDUCED SPRINKLES/SHOWERS THAT EARLIER
STARTED TO DEVELOP WITHIN THE EASTERN FRINGES OF THE CWA HAS SINCE
ADVECTED 1+ COUNTY EAST OF OUR AREA PER THE LATEST RADAR/SATELLITE
TRENDS. THUS WILL FORGE AHEAD WITH NO PRECIP MENTION WHATSOEVER
THROUGH THE NEXT 24 HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM CDT FRI JUL 12 2013
THE PRIMARY ISSUE DURING THE NEXT 24 HOURS IS DETERMINING HOW HOT
WE ACTUALLY GET TODAY/HOW CLOSE WE GET TO HEAT ADVISORY
CRITERIA...AND HOW CLOSE TO CRITICAL FIRE DANGER WESTERN PARTS OF
NORTH CENTRAL KANSAS MIGHT GET. ALTHOUGH THE FORECAST PRODUCTS
CARRY NO MENTION OF SHOWERS/THUNDERSTORMS DUE TO POPS HOLDING BELOW
15 PERCENT...POPS ARE NOT NECESSARILY ZERO...AND WILL HAVE TO KEEP
AN EYE ESPECIALLY ON FAR WESTERN/NORTHERN COUNTIES LATE THIS
AFTERNOON-TONIGHT FOR THE REMOTE CHANCE THAT A FEW STORMS COULD
POP UP OR MOVE IN FROM THE WEST/NORTH. IN THE IMMEDIATE NEXT FEW
HOURS...ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW HIGH-
BASED SHOWERS/STORMS COULD TRY DEVELOPING IN EASTERN ZONES BEFORE
SUNRISE.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS A FAIRLY ILL-DEFINED QUASI-
STATIONARY FRONT SNAKING FROM A 1000 MILLIBAR LOW IN NORTHWEST
SD...SOUTHWARD THROUGH WESTERN NEBRASKA INTO NORTHWEST/SOUTH CENTRAL
KS. OFF TO THE EAST...A 1019MB HIGH IS CENTERED NEAR THE IA/IL
BORDER. BETWEEN THE FRONT AND THE HIGH...FAIRLY STEADY SOUTH-
SOUTHEAST BREEZES OF 8-15 MPH WITH OCCASIONAL GUSTS OVER 20 ARE IN
PLACE ACROSS THE CWA EARLY THIS MORNING...WITH THESE BREEZES
EXPECTED TO HELP HOLD LOW TEMPS UP BETWEEN 69-74 IN MOST AREAS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A
FAIRLY EXPANSIVE MID/UPPER LEVEL RIDGE AXIS THAT HAS BUILT
NORTHEAST SINCE 24 HOURS AGO TO ENCOMPASS MUCH OF THE
CENTRAL/SOUTH CENTRAL CONUS. THE CENTER AXIS OF THIS RIDGE...AT
ROUGHLY 590 DECAMETER...RUNS FROM ROUGHLY THE LOCAL CWA ON THE
NORTHEAST EDGE...BACK SOUTHWESTWARD TOWARD THE NM/TX BORDER. WITH
THIS RIDGE AXIS NEARLY OVERHEAD...THE FLOW OVER THE CWA AT 500MB
IS FAIRLY LIGHT/VARIABLE...WHILE A BIT LOWER AT 700MB...THERE IS
MODEST WEST-SOUTHWEST FLOW. A NARROW ZONE OF THETA-E ADVECTION
ALONG A FAIRLY TIGHT 700MB MOISTURE GRADIENT HAS RESULTED IN A
SCATTERED ACCAS FIELD WITHIN ROUGHLY THE EASTERN 1/3 OF THE CWA
TONIGHT...AND RECENTLY THE FIRST FEW HINTS OF ISOLATED ELEVATED
SPRINKLES/LIGHT SHOWERS HAVE SHOWED UP ON RADAR WITHIN A FEW OF
OUR EASTERN COUNTIES.
STARTING WITH THE MOST IMMEDIATE ISSUE...WILL BE CLOSELY
MONITORING RADAR TRENDS IN EASTERN ZONES PRIOR TO SUNRISE TO SEE
WHETHER THE AFOREMENTIONED VERY ISOLATED CONVECTION CAN BE COVERED
WITH A SPRINKLE MENTION...OR MIGHT NEED SOMETHING MORE.
THE LATEST RAP HAS CAUGHT ONTO THIS DEVELOPMENT...AND SUGGESTS
THAT MAINLY OUR FAR EASTERN COUNTIES NEAR THE HWY 81 CORRIDOR
COULD CONTINUE TO SEE SOME OF THIS PRE-DAWN ACTIVITY...BUT THAT IT
SHOULD LARGELY BE DONE OR ADVECTED EAST OF THE CWA BY 7AM/12Z. PER
FORECAST SOUNDINGS...PARCELS ROOTED NEAR 700MB COULD POTENTIALLY
HAVE UP TO AROUND 400 J/KG MUCAPE AVAILABLE TO THEM...SO A BRIEF
FLARE UP OF NON-SEVERE THUNDERSTORMS IS NOT COMPLETELY OUT OF THE
QUESTION. FOR NOW...WILL ONLY MENTION ISOLATED SPRINKLES IN OUR
EASTERN FEW COLUMNS OF NEBRASKA COUNTIES THROUGH 12Z TO COVER
THINGS...PENDING ANY EVIDENCE OTHERWISE.
TURNING TO THE DAYTIME HOURS...THE MAIN STORY WILL BE A RETURN OF
LEGITIMATE SUMMER HEAT...BUT DOES NOT APPEAR TO BE HEADLINE-
WORTHY. IN THE MID/UPPER LEVELS...THE DOMINANT RIDGE AXIS WILL
CONTINUE TO EXPAND ACROSS THE CENTRAL PLAINS IN A SOUTHWEST-
NORTHEAST FASHION...WITH PARTS OF THE CWA ALIGNED ALMOST DIRECTLY
UNDER ITS CENTER AXIS. AT THE SURFACE...A FAIRLY SHARP TROUGH
AXIS WILL SET UP FROM FAR EASTERN CO ACROSS NORTHWEST NEB INTO
CENTRAL SD BY MID-LATE AFTERNOON...EXTENDING FROM A ROUGHLY 1000MB
LOW CENTERED NEAR THE CO/KS BORDER. THE LOCAL CWA WILL REMAIN IN
THE OPEN WARM SECTOR SOLIDLY SOUTHEAST OF THIS TROUGH AXIS...AND
THUS WILL SEE A CONTINUATION OF FAIRLY BREEZY SOUTH-SOUTHEAST
WINDS...WITH SUSTAINED SPEEDS MOST ALL AREAS 15-20 MPH AND GUSTS
25 TO POSSIBLY 30 MPH AT TIMES. AS FOR CONVECTIVE CHANCES...ASIDE
FROM ANY EARLY MORNING ACTIVITY IN THE EAST...THERE IS LITTLE IF
ANY RISK OF SHOWERS/STORMS TODAY AS WARM MID LEVEL TEMPS WITHIN
THE RIDGE AXIS SHOULD SERVE TO CAP THINGS OFF PRETTY SOLIDLY. ONE
OF THE ONLY POSSIBLE CAVEATS...AS DEPICTED BY THE LATEST RAP
RUNS...IS THAT STRONG HEATING AND VERY DEEP MIXING COULD POP A FEW
HIGH-BASED STORMS LATE IN THE AFTERNOON ALONG WESTERN PORTIONS OF
THE NEB/KS BORDER...WITH SOME OF THIS ACTIVITY POSSIBLY ADVECTING
EAST INTO THE DAWSON-FURNAS COUNTY CORRIDOR...BUT THE ODDS OF THIS
SEEM LOW ENOUGH TO STICK WITH SILENT 10 POPS FOR NOW...AS MOST
LATE AFTERNOON STORMS SHOULD FOCUS WELL TO OUR NORTHWEST ALONG THE
AFOREMENTIONED TROUGH AXIS. TEMP-WISE...BASED ON HOW HIGHS TURNED
OUT YESTERDAY...IT APPEARS THE NAM AND ASSOCIATED MET GUIDANCE HAS
BEEN A BIT AGGRESSIVE WITH THE HEAT...AND AS A RESULT...HAVE
SHAVED A FEW DEGREES OFF HIGHS TODAY IN MOST AREAS...USING VALUES
A BIT CLOSER TO GFS MAV GUIDANCE AND A MULTI-MODEL BLEND. THIS STILL
YIELDS A VERY TOASTY DAY WITH HIGHS RANGING FROM MID 90S NORTHEAST
...MID-UPPER 90S CENTRAL AND UPPER 90S TO AROUND 102 IN KS ZONES
AND NEAR THE STATE LINE. AS FOR DEWPOINTS...NOT EXPECTING A
DRAMATIC MIX-DOWN TODAY GIVEN THAT WINDS WILL BE MORE SOUTHERLY
VERSUS SOUTHWESTERLY...BUT NUDGED THEM DOWN A BIT ESPECIALLY IN
WESTERN ZONES...RANGING FROM UPPER 50S AT MID-AFTERNOON IN THE FAR
WEST TO MID-UPPER 60S IN THE EAST. THE RESULTANT HEAT INDEX VALUES
PEAK IN THE 98-100 RANGE ACROSS MOST OF THE NEB CWA...WITH KS
ZONES AND AREAS NEAR THE STATE LINE MORE LIKELY TO REACH THE
101-104 RANGE. BOTTOM LINE HERE IS...THESE VALUES ARE CERTAINLY
WORTH A HAZARDOUS WEATHER OUTLOOK MENTION...BUT DO NOT JUSTIFY A
FORMAL HEAT ADVISORY BASED ON OUR 105+ LOCAL CRITERIA. PLEASE NOTE
THAT THE NORTH PLATTE/LBF CWA HAS A SLIGHTLY COOLER
...CLIMATOLOGICALLY-BASED HEAT ADVISORY CRITERIA OF 100+...AND
THIS IS WHY A FORMAL HEADLINE IS OUT FOR THEIR AREA...BUT NOT FOR
OURS.
TURNING TO THIS EVENING/TONIGHT POST-7PM/00Z...THE MAIN STORY
VERSUS PREVIOUS FORECAST IS THAT THE SLIGHT CHANCE OF
THUNDERSTORMS HAS BEEN TRIMMED FROM THE EXTREME NORTHERN/WEST-
CENTRAL EDGES OF THE CWA...AND THUS WILL CARRY A STORM-FREE
FORECAST CWA-WIDE. AGAIN THOUGH...WILL EMPHASIZE THAT SILENT 10
POPS WILL REMAIN IN PLACE ESPECIALLY IN NORTHERN/WESTERN COUNTIES
TO AT LEAST ACKNOWLEDGE THAT A VERY LOW PROBABILITY OF SOME
ACTIVITY IS NOT COMPLETELY OUT OF THE QUESTION. IN THE MID-UPPER
LEVELS...THERE IS VERY LITTLE CHANGE WITH THE STRENGTH/ORIENTATION
OF THE EXPANSIVE RIDGE AXIS...AS IT REMAINS DRAPED FROM SOUTHWEST-
NORTHEAST ACROSS THE HEART OF THE CENTRAL PLAINS. A BIT LOWER AT
850MB...A 40+KT SOUTHERLY LOW LEVEL JET CRANKS UP THROUGH THE
NIGHT FROM WESTERN KS ACROSS CENTRAL NEB INTO EASTERN SD/WESTERN
MN...HELPING TO FOCUS THE VAST MAJORITY OF REGIONAL CONVECTION
NEAR THE EXIT REGION OF THIS FEATURE FROM NORTHEAST CO ACROSS
NORTHWEST NEB INTO SD/MN. AT THE SURFACE...THERE WILL ALSO BE
LITTLE OVERALL CHANGE FROM THE DAYTIME HOURS...WITH THE TROUGH
AXIS PERSISTING FROM NEAR THE KS/CO BORDER NORTH-NORTHEAST INTO
CENTRAL SD. WITH A CONTINUED MODEST PRESSURE GRADIENT AND LIMITED
MIXING UNDER THE LOW LEVEL JET...SURFACE BREEZES ACROSS THE CWA
WILL AGAIN AVERAGE 10-15 MPH FROM THE SOUTH-SOUTHEAST. ASSUMING
THAT POTENTIALLY ROGUE LATE AFTERNOON/EARLY EVENING STORMS DO NOT
AFFECT THE FAR WESTERN CWA...ITS PRETTY APPARENT FROM MOST MODEL
DEPICTIONS THAT OVERNIGHT CONVECTION SHOULD FOCUS AT LEAST 50-100
MILES NORTH THROUGH NORTHWEST OF THE CWA...AND GENERALLY LIFT
NORTH WITH TIME. THE ONLY FORESEEABLE CAVEAT HERE WOULD BE IF
NORTHERN NEB STORMS DEVELOP A COLD POOL AND START TO BUILD
SOUTHWARD INTO THE LOW LEVEL JET AXIS...POTENTIALLY REACHING THE
NORTHERN PARTS OF THE CWA. INTERESTINGLY...AT LEAST ONE
MODEL...THE 4KM WRF-NMM FROM PSU...DOES DEPICT THIS SCENARIO...BUT
GIVEN SUCH LIMITED SUPPORT WILL KEEP IT STORM-FREE FOR NOW. WILL
ALSO NOTE THAT THE 00Z GFS DEPICTION OF LATE NIGHT STORMS FLARING
UP NEAR HIGHWAY 81...LIKELY IN RESPONSE TO ANOTHER SUBTLE BATCH OF
MID LEVEL THETA-E ADVECTION...HAS BEEN DISREGARDED AS AN OUTLIER
AS WELL FOR THIS FORECAST. LOW TEMPERATURES WERE CHANGED
LITTLE...AND AGAIN REFLECT A SLIGHT UPWARD TREND FROM THE PAST FEW
NIGHTS...WITH MOST AREAS PROGGED TO BOTTOM OUT 72-75.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 431 AM CDT FRI JUL 12 2013
FOCUS FOR THIS TIMEFRAME WILL INVOLVE BOTH HIGH TEMPERATURES AND
PRECIPITATION CHANCES. MOST OF THE OPERATIONAL MODELS ARE COMING
INTO AGREEMENT ON THE UNUSUAL PATTERN EXPECTED IN THE SATURDAY TO
THURSDAY PERIOD. THEY ARE TAKING THE MID/UPPER LEVEL LOW PRESSURE
CURRENTLY SITTING OVER OHIO...AND RETROGRADING IT BACK TO THE
WEST. BY 12Z SAT THE GFS HAS IT OVER CENTRAL TENN...WHILE THE EC
PLACES IT A LITTLE NORTH OF THERE OVER KENTUCKY...AND THE NAM IS
BETWEEN THE TWO. BY 12Z SUNDAY THESE MODELS HAVE IT FROM CENTRAL
MISSOURI TO WESTERN ARKANSAS. THIS WESTWARD PUSH IS PROGGED TO
CONTINUE AND BY 12Z MONDAY IT IS FORECAST TO BE FROM NORTHERN
OKLAHOMA TO NORTHERN TEXAS. IT THEN APPEARS TO REMAIN OVER THE
TEXAS PANHANDLE OR IN NORTHEASTERN NEW MEXICO WHILE GRADUALLY
FILLING INTO THE WORKWEEK.
THIS IS NOT A VERY COMMON SCENARIO AND IF IT DOES COME TO FRUITION
WOULD MEAN COOLER TEMPERATURES STARTING SUNDAY. IN THE PAST 24
HRS...THE EXPECTED 850 MB TEMPS FOR SUNDAY OVER OUR AREA HAVE
DECREASED ABOUT 8-10 DEGREES C. GIVEN THE CONSISTENCY OF THE VARIOUS
OPERATIONAL MODELS WILL BUY INTO THIS SCENARIO AND LOWER HIGHS ON
SUNDAY BY SEVERAL DEGREES. SIMILAR TEMPERATURES CAN BE EXPECTED ON
MONDAY AND TUESDAY. WHILE COOLER THAN THOSE EXPECTED FOR TODAY AND
SATURDAY...WOULD NOT EXACTLY CALL IT COOL WEATHER AS HIGHS WILL
ACTUALLY BE AROUND NORMAL FOR THIS TIME OF YEAR FOR SUN-TUES. AFTER
THAT WE SHOULD SEE A GRADUAL WARMUP AS RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION.
PRECIPITATION CONTINUES TO BE DIFFICULT TO FORECAST. LOOKS LIKE
THERE ARE AT LEAST SLIGHT CHANCES ON SAT AND SUNDAY NIGHTS OVER MUCH
OF THE CWA WITH A SURFACE BOUNDARY JUST TO OUR WEST...WEAK WAVES
ROTATING JUST TO OUR NORTH ALONG THE NORTHERN JET...AND THE
APPROACHING RETROGRADING LOW MENTIONED ABOVE. WILL CONTINUE TO
FORECAST DRY WEATHER FOR THE UPCOMING WORKWEEK BUT THAT MAY CHANGE
DEPENDING HOW FAR NORTH THAT RETROGRADING LOW TRACKS. AT
PRESENT...IT MAY AFFECT THE KANSAS PART OF OUR CWA BUT THE FURTHER
NORTH ITS TRACK...THE BETTER THE CHANCE FOR SOME RAIN IN THE NEB
PART OF OUR CWA.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM CDT FRI JUL 12 2013
THERE IS FAIRLY HIGH CONFIDENCE THAT VFR CEILING/VISIBILITY WILL
PREVAIL THROUGH THE PERIOD...WITH MID/UPPER LEVEL HIGH PRESSURE
DOMINATING THE LOCAL WEATHER PATTERN AND PROVIDING MOSTLY CLEAR
SKIES...AND VERY LITTLE IF ANY RISK OF A SHOWER/THUNDERSTORM. AS
FOR SURFACE WINDS...A RATHER CONSTANT SOUTH-SOUTHEAST DIRECTION
WILL PREVAIL THROUGHOUT THE PERIOD...AND IT WILL REMAIN FAIRLY
BREEZY MOST OF THE TIME...WITH GUSTS COMMONLY UP TO AROUND
18KT...AND DAYTIME GUST POTENTIAL TO AT LEAST 25KT. THE ONLY REAL
ISSUE OF NOTE IS LOW LEVEL WIND SHEAR UNDERNEATH A NOCTURNAL LOW
LEVEL JET. WILL CONTINUE A MENTION OF MARGINAL LLWS FOR THE FIRST
FEW HOURS THIS MORNING...AND THEN BRING BACK ANOTHER ROUND OF LLWS
FOR THE EARLY SATURDAY MORNING HOURS THANKS TO A SIMILAR
SETUP...WITH 30+KT OF BULK SHEAR DIFFERENCE BETWEEN THE SURFACE
AND APPROXIMATELY 1500 FT AGL...WHERE SUSTAINED SOUTH-SOUTHWEST
WINDS UP TO AROUND 43KT WILL DEVELOP.
&&
.FIRE WEATHER...
ISSUED AT 431 AM CDT FRI JUL 12 2013
ALTHOUGH CRITICAL FIRE WEATHER CONDITIONS/DANGER ARE NOT
ANTICIPATED WITHIN THE CWA TODAY...NEAR-CRITICAL CONDITIONS ARE
FORECAST ESPECIALLY IN THE FAR SOUTHWEST IN THE PHILLIPS/ROOKS
COUNTY AREAS...AND THUS WILL INTRODUCE THIS MENTION INTO THE
HAZARDOUS WEATHER OUTLOOK. THIS AREA WILL FEATURE THE GREATEST
OVERLAP OF SUSTAINED WINDS/GUSTS 20/25 MPH...AND RELATIVE HUMIDITY
VALUES NEAR OR SLIGHTLY BELOW 25 PERCENT. CERTAINLY...AT LEAST A
LIMITED FIRE DANGER WILL EXIST ELSEWHERE ACROSS THE CWA GIVEN THE
STEADY BREEZES AND OVERALL DRY CONDITIONS OF LATE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...EWALD
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
636 AM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 635 AM CDT FRI JUL 12 2013
THE NARROW LINE OF ACCAS-INDUCED SHOWERS THAT EARLIER FLIRTED WITH
THE EASTERN FRINGES OF THE CWA AS SINCE ADVECTED 1+ COUNTY EAST OF
OUR AREA PER THE LATEST RADAR/SATELLITE TRENDS. THUS WILL FORGE
AHEAD WITH NO PRECIP MENTION WHATSOEVER THROUGH THE NEXT 24 HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM CDT FRI JUL 12 2013
THE PRIMARY ISSUE DURING THE NEXT 24 HOURS IS DETERMINING HOW HOT
WE ACTUALLY GET TODAY/HOW CLOSE WE GET TO HEAT ADVISORY
CRITERIA...AND HOW CLOSE TO CRITICAL FIRE DANGER WESTERN PARTS OF
NORTH CENTRAL KANSAS MIGHT GET. ALTHOUGH THE FORECAST PRODUCTS
CARRY NO MENTION OF SHOWERS/THUNDERSTORMS DUE TO POPS HOLDING BELOW
15 PERCENT...POPS ARE NOT NECESSARILY ZERO...AND WILL HAVE TO KEEP
AN EYE ESPECIALLY ON FAR WESTERN/NORTHERN COUNTIES LATE THIS
AFTERNOON-TONIGHT FOR THE REMOTE CHANCE THAT A FEW STORMS COULD
POP UP OR MOVE IN FROM THE WEST/NORTH. IN THE IMMEDIATE NEXT FEW
HOURS...ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW HIGH-
BASED SHOWERS/STORMS COULD TRY DEVELOPING IN EASTERN ZONES BEFORE
SUNRISE.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS A FAIRLY ILL-DEFINED QUASI-
STATIONARY FRONT SNAKING FROM A 1000 MILLIBAR LOW IN NORTHWEST
SD...SOUTHWARD THROUGH WESTERN NEBRASKA INTO NORTHWEST/SOUTH CENTRAL
KS. OFF TO THE EAST...A 1019MB HIGH IS CENTERED NEAR THE IA/IL
BORDER. BETWEEN THE FRONT AND THE HIGH...FAIRLY STEADY SOUTH-
SOUTHEAST BREEZES OF 8-15 MPH WITH OCCASIONAL GUSTS OVER 20 ARE IN
PLACE ACROSS THE CWA EARLY THIS MORNING...WITH THESE BREEZES
EXPECTED TO HELP HOLD LOW TEMPS UP BETWEEN 69-74 IN MOST AREAS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A
FAIRLY EXPANSIVE MID/UPPER LEVEL RIDGE AXIS THAT HAS BUILT
NORTHEAST SINCE 24 HOURS AGO TO ENCOMPASS MUCH OF THE
CENTRAL/SOUTH CENTRAL CONUS. THE CENTER AXIS OF THIS RIDGE...AT
ROUGHLY 590 DECAMETER...RUNS FROM ROUGHLY THE LOCAL CWA ON THE
NORTHEAST EDGE...BACK SOUTHWESTWARD TOWARD THE NM/TX BORDER. WITH
THIS RIDGE AXIS NEARLY OVERHEAD...THE FLOW OVER THE CWA AT 500MB
IS FAIRLY LIGHT/VARIABLE...WHILE A BIT LOWER AT 700MB...THERE IS
MODEST WEST-SOUTHWEST FLOW. A NARROW ZONE OF THETA-E ADVECTION
ALONG A FAIRLY TIGHT 700MB MOISTURE GRADIENT HAS RESULTED IN A
SCATTERED ACCAS FIELD WITHIN ROUGHLY THE EASTERN 1/3 OF THE CWA
TONIGHT...AND RECENTLY THE FIRST FEW HINTS OF ISOLATED ELEVATED
SPRINKLES/LIGHT SHOWERS HAVE SHOWED UP ON RADAR WITHIN A FEW OF
OUR EASTERN COUNTIES.
STARTING WITH THE MOST IMMEDIATE ISSUE...WILL BE CLOSELY
MONITORING RADAR TRENDS IN EASTERN ZONES PRIOR TO SUNRISE TO SEE
WHETHER THE AFOREMENTIONED VERY ISOLATED CONVECTION CAN BE COVERED
WITH A SPRINKLE MENTION...OR MIGHT NEED SOMETHING MORE.
THE LATEST RAP HAS CAUGHT ONTO THIS DEVELOPMENT...AND SUGGESTS
THAT MAINLY OUR FAR EASTERN COUNTIES NEAR THE HWY 81 CORRIDOR
COULD CONTINUE TO SEE SOME OF THIS PRE-DAWN ACTIVITY...BUT THAT IT
SHOULD LARGELY BE DONE OR ADVECTED EAST OF THE CWA BY 7AM/12Z. PER
FORECAST SOUNDINGS...PARCELS ROOTED NEAR 700MB COULD POTENTIALLY
HAVE UP TO AROUND 400 J/KG MUCAPE AVAILABLE TO THEM...SO A BRIEF
FLARE UP OF NON-SEVERE THUNDERSTORMS IS NOT COMPLETELY OUT OF THE
QUESTION. FOR NOW...WILL ONLY MENTION ISOLATED SPRINKLES IN OUR
EASTERN FEW COLUMNS OF NEBRASKA COUNTIES THROUGH 12Z TO COVER
THINGS...PENDING ANY EVIDENCE OTHERWISE.
TURNING TO THE DAYTIME HOURS...THE MAIN STORY WILL BE A RETURN OF
LEGITIMATE SUMMER HEAT...BUT DOES NOT APPEAR TO BE HEADLINE-
WORTHY. IN THE MID/UPPER LEVELS...THE DOMINANT RIDGE AXIS WILL
CONTINUE TO EXPAND ACROSS THE CENTRAL PLAINS IN A SOUTHWEST-
NORTHEAST FASHION...WITH PARTS OF THE CWA ALIGNED ALMOST DIRECTLY
UNDER ITS CENTER AXIS. AT THE SURFACE...A FAIRLY SHARP TROUGH
AXIS WILL SET UP FROM FAR EASTERN CO ACROSS NORTHWEST NEB INTO
CENTRAL SD BY MID-LATE AFTERNOON...EXTENDING FROM A ROUGHLY 1000MB
LOW CENTERED NEAR THE CO/KS BORDER. THE LOCAL CWA WILL REMAIN IN
THE OPEN WARM SECTOR SOLIDLY SOUTHEAST OF THIS TROUGH AXIS...AND
THUS WILL SEE A CONTINUATION OF FAIRLY BREEZY SOUTH-SOUTHEAST
WINDS...WITH SUSTAINED SPEEDS MOST ALL AREAS 15-20 MPH AND GUSTS
25 TO POSSIBLY 30 MPH AT TIMES. AS FOR CONVECTIVE CHANCES...ASIDE
FROM ANY EARLY MORNING ACTIVITY IN THE EAST...THERE IS LITTLE IF
ANY RISK OF SHOWERS/STORMS TODAY AS WARM MID LEVEL TEMPS WITHIN
THE RIDGE AXIS SHOULD SERVE TO CAP THINGS OFF PRETTY SOLIDLY. ONE
OF THE ONLY POSSIBLE CAVEATS...AS DEPICTED BY THE LATEST RAP
RUNS...IS THAT STRONG HEATING AND VERY DEEP MIXING COULD POP A FEW
HIGH-BASED STORMS LATE IN THE AFTERNOON ALONG WESTERN PORTIONS OF
THE NEB/KS BORDER...WITH SOME OF THIS ACTIVITY POSSIBLY ADVECTING
EAST INTO THE DAWSON-FURNAS COUNTY CORRIDOR...BUT THE ODDS OF THIS
SEEM LOW ENOUGH TO STICK WITH SILENT 10 POPS FOR NOW...AS MOST
LATE AFTERNOON STORMS SHOULD FOCUS WELL TO OUR NORTHWEST ALONG THE
AFOREMENTIONED TROUGH AXIS. TEMP-WISE...BASED ON HOW HIGHS TURNED
OUT YESTERDAY...IT APPEARS THE NAM AND ASSOCIATED MET GUIDANCE HAS
BEEN A BIT AGGRESSIVE WITH THE HEAT...AND AS A RESULT...HAVE
SHAVED A FEW DEGREES OFF HIGHS TODAY IN MOST AREAS...USING VALUES
A BIT CLOSER TO GFS MAV GUIDANCE AND A MULTI-MODEL BLEND. THIS STILL
YIELDS A VERY TOASTY DAY WITH HIGHS RANGING FROM MID 90S NORTHEAST
...MID-UPPER 90S CENTRAL AND UPPER 90S TO AROUND 102 IN KS ZONES
AND NEAR THE STATE LINE. AS FOR DEWPOINTS...NOT EXPECTING A
DRAMATIC MIX-DOWN TODAY GIVEN THAT WINDS WILL BE MORE SOUTHERLY
VERSUS SOUTHWESTERLY...BUT NUDGED THEM DOWN A BIT ESPECIALLY IN
WESTERN ZONES...RANGING FROM UPPER 50S AT MID-AFTERNOON IN THE FAR
WEST TO MID-UPPER 60S IN THE EAST. THE RESULTANT HEAT INDEX VALUES
PEAK IN THE 98-100 RANGE ACROSS MOST OF THE NEB CWA...WITH KS
ZONES AND AREAS NEAR THE STATE LINE MORE LIKELY TO REACH THE
101-104 RANGE. BOTTOM LINE HERE IS...THESE VALUES ARE CERTAINLY
WORTH A HAZARDOUS WEATHER OUTLOOK MENTION...BUT DO NOT JUSTIFY A
FORMAL HEAT ADVISORY BASED ON OUR 105+ LOCAL CRITERIA. PLEASE NOTE
THAT THE NORTH PLATTE/LBF CWA HAS A SLIGHTLY COOLER
...CLIMATOLOGICALLY-BASED HEAT ADVISORY CRITERIA OF 100+...AND
THIS IS WHY A FORMAL HEADLINE IS OUT FOR THEIR AREA...BUT NOT FOR
OURS.
TURNING TO THIS EVENING/TONIGHT POST-7PM/00Z...THE MAIN STORY
VERSUS PREVIOUS FORECAST IS THAT THE SLIGHT CHANCE OF
THUNDERSTORMS HAS BEEN TRIMMED FROM THE EXTREME NORTHERN/WEST-
CENTRAL EDGES OF THE CWA...AND THUS WILL CARRY A STORM-FREE
FORECAST CWA-WIDE. AGAIN THOUGH...WILL EMPHASIZE THAT SILENT 10
POPS WILL REMAIN IN PLACE ESPECIALLY IN NORTHERN/WESTERN COUNTIES
TO AT LEAST ACKNOWLEDGE THAT A VERY LOW PROBABILITY OF SOME
ACTIVITY IS NOT COMPLETELY OUT OF THE QUESTION. IN THE MID-UPPER
LEVELS...THERE IS VERY LITTLE CHANGE WITH THE STRENGTH/ORIENTATION
OF THE EXPANSIVE RIDGE AXIS...AS IT REMAINS DRAPED FROM SOUTHWEST-
NORTHEAST ACROSS THE HEART OF THE CENTRAL PLAINS. A BIT LOWER AT
850MB...A 40+KT SOUTHERLY LOW LEVEL JET CRANKS UP THROUGH THE
NIGHT FROM WESTERN KS ACROSS CENTRAL NEB INTO EASTERN SD/WESTERN
MN...HELPING TO FOCUS THE VAST MAJORITY OF REGIONAL CONVECTION
NEAR THE EXIT REGION OF THIS FEATURE FROM NORTHEAST CO ACROSS
NORTHWEST NEB INTO SD/MN. AT THE SURFACE...THERE WILL ALSO BE
LITTLE OVERALL CHANGE FROM THE DAYTIME HOURS...WITH THE TROUGH
AXIS PERSISTING FROM NEAR THE KS/CO BORDER NORTH-NORTHEAST INTO
CENTRAL SD. WITH A CONTINUED MODEST PRESSURE GRADIENT AND LIMITED
MIXING UNDER THE LOW LEVEL JET...SURFACE BREEZES ACROSS THE CWA
WILL AGAIN AVERAGE 10-15 MPH FROM THE SOUTH-SOUTHEAST. ASSUMING
THAT POTENTIALLY ROGUE LATE AFTERNOON/EARLY EVENING STORMS DO NOT
AFFECT THE FAR WESTERN CWA...ITS PRETTY APPARENT FROM MOST MODEL
DEPICTIONS THAT OVERNIGHT CONVECTION SHOULD FOCUS AT LEAST 50-100
MILES NORTH THROUGH NORTHWEST OF THE CWA...AND GENERALLY LIFT
NORTH WITH TIME. THE ONLY FORESEEABLE CAVEAT HERE WOULD BE IF
NORTHERN NEB STORMS DEVELOP A COLD POOL AND START TO BUILD
SOUTHWARD INTO THE LOW LEVEL JET AXIS...POTENTIALLY REACHING THE
NORTHERN PARTS OF THE CWA. INTERESTINGLY...AT LEAST ONE
MODEL...THE 4KM WRF-NMM FROM PSU...DOES DEPICT THIS SCENARIO...BUT
GIVEN SUCH LIMITED SUPPORT WILL KEEP IT STORM-FREE FOR NOW. WILL
ALSO NOTE THAT THE 00Z GFS DEPICTION OF LATE NIGHT STORMS FLARING
UP NEAR HIGHWAY 81...LIKELY IN RESPONSE TO ANOTHER SUBTLE BATCH OF
MID LEVEL THETA-E ADVECTION...HAS BEEN DISREGARDED AS AN OUTLIER
AS WELL FOR THIS FORECAST. LOW TEMPERATURES WERE CHANGED
LITTLE...AND AGAIN REFLECT A SLIGHT UPWARD TREND FROM THE PAST FEW
NIGHTS...WITH MOST AREAS PROGGED TO BOTTOM OUT 72-75.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 431 AM CDT FRI JUL 12 2013
FOCUS FOR THIS TIMEFRAME WILL INVOLVE BOTH HIGH TEMPERATURES AND
PRECIPITATION CHANCES. MOST OF THE OPERATIONAL MODELS ARE COMING
INTO AGREEMENT ON THE UNUSUAL PATTERN EXPECTED IN THE SATURDAY TO
THURSDAY PERIOD. THEY ARE TAKING THE MID/UPPER LEVEL LOW PRESSURE
CURRENTLY SITTING OVER OHIO...AND RETROGRADING IT BACK TO THE
WEST. BY 12Z SAT THE GFS HAS IT OVER CENTRAL TENN...WHILE THE EC
PLACES IT A LITTLE NORTH OF THERE OVER KENTUCKY...AND THE NAM IS
BETWEEN THE TWO. BY 12Z SUNDAY THESE MODELS HAVE IT FROM CENTRAL
MISSOURI TO WESTERN ARKANSAS. THIS WESTWARD PUSH IS PROGGED TO
CONTINUE AND BY 12Z MONDAY IT IS FORECAST TO BE FROM NORTHERN
OKLAHOMA TO NORTHERN TEXAS. IT THEN APPEARS TO REMAIN OVER THE
TEXAS PANHANDLE OR IN NORTHEASTERN NEW MEXICO WHILE GRADUALLY
FILLING INTO THE WORKWEEK.
THIS IS NOT A VERY COMMON SCENARIO AND IF IT DOES COME TO FRUITION
WOULD MEAN COOLER TEMPERATURES STARTING SUNDAY. IN THE PAST 24
HRS...THE EXPECTED 850 MB TEMPS FOR SUNDAY OVER OUR AREA HAVE
DECREASED ABOUT 8-10 DEGREES C. GIVEN THE CONSISTENCY OF THE VARIOUS
OPERATIONAL MODELS WILL BUY INTO THIS SCENARIO AND LOWER HIGHS ON
SUNDAY BY SEVERAL DEGREES. SIMILAR TEMPERATURES CAN BE EXPECTED ON
MONDAY AND TUESDAY. WHILE COOLER THAN THOSE EXPECTED FOR TODAY AND
SATURDAY...WOULD NOT EXACTLY CALL IT COOL WEATHER AS HIGHS WILL
ACTUALLY BE AROUND NORMAL FOR THIS TIME OF YEAR FOR SUN-TUES. AFTER
THAT WE SHOULD SEE A GRADUAL WARMUP AS RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION.
PRECIPITATION CONTINUES TO BE DIFFICULT TO FORECAST. LOOKS LIKE
THERE ARE AT LEAST SLIGHT CHANCES ON SAT AND SUNDAY NIGHTS OVER MUCH
OF THE CWA WITH A SURFACE BOUNDARY JUST TO OUR WEST...WEAK WAVES
ROTATING JUST TO OUR NORTH ALONG THE NORTHERN JET...AND THE
APPROACHING RETROGRADING LOW MENTIONED ABOVE. WILL CONTINUE TO
FORECAST DRY WEATHER FOR THE UPCOMING WORKWEEK BUT THAT MAY CHANGE
DEPENDING HOW FAR NORTH THAT RETROGRADING LOW TRACKS. AT
PRESENT...IT MAY AFFECT THE KANSAS PART OF OUR CWA BUT THE FURTHER
NORTH ITS TRACK...THE BETTER THE CHANCE FOR SOME RAIN IN THE NEB
PART OF OUR CWA.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM CDT FRI JUL 12 2013
THERE IS FAIRLY HIGH CONFIDENCE THAT VFR CEILING/VISIBILITY WILL
PREVAIL THROUGH THE PERIOD...WITH MID/UPPER LEVEL HIGH PRESSURE
DOMINATING THE LOCAL WEATHER PATTERN AND PROVIDING MOSTLY CLEAR
SKIES...AND VERY LITTLE IF ANY RISK OF A SHOWER/THUNDERSTORM. AS
FOR SURFACE WINDS...A RATHER CONSTANT SOUTH-SOUTHEAST DIRECTION
WILL PREVAIL THROUGHOUT THE PERIOD...AND IT WILL REMAIN FAIRLY
BREEZY MOST OF THE TIME...WITH GUSTS COMMONLY UP TO AROUND
18KT...AND DAYTIME GUST POTENTIAL TO AT LEAST 25KT. THE ONLY REAL
ISSUE OF NOTE IS LOW LEVEL WIND SHEAR UNDERNEATH A NOCTURNAL LOW
LEVEL JET. WILL CONTINUE A MENTION OF MARGINAL LLWS FOR THE FIRST
FEW HOURS THIS MORNING...AND THEN BRING BACK ANOTHER ROUND OF LLWS
FOR THE EARLY SATURDAY MORNING HOURS THANKS TO A SIMILAR
SETUP...WITH 30+KT OF BULK SHEAR DIFFERENCE BETWEEN THE SURFACE
AND APPROXIMATELY 1500 FT AGL...WHERE SUSTAINED SOUTH-SOUTHWEST
WINDS UP TO AROUND 43KT WILL DEVELOP.
&&
.FIRE WEATHER...
ISSUED AT 431 AM CDT FRI JUL 12 2013
ALTHOUGH CRITICAL FIRE WEATHER CONDITIONS/DANGER ARE NOT
ANTICIPATED WITHIN THE CWA TODAY...NEAR-CRITICAL CONDITIONS ARE
FORECAST ESPECIALLY IN THE FAR SOUTHWEST IN THE PHILLIPS/ROOKS
COUNTY AREAS...AND THUS WILL INTRODUCE THIS MENTION INTO THE
HAZARDOUS WEATHER OUTLOOK. THIS AREA WILL FEATURE THE GREATEST
OVERLAP OF SUSTAINED WINDS/GUSTS 20/25 MPH...AND RELATIVE HUMIDITY
VALUES NEAR OR SLIGHTLY BELOW 25 PERCENT. CERTAINLY...AT LEAST A
LIMITED FIRE DANGER WILL EXIST ELSEWHERE ACROSS THE CWA GIVEN THE
STEADY BREEZES AND OVERALL DRY CONDITIONS OF LATE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...EWALD
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
432 AM CDT FRI JUL 12 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM CDT FRI JUL 12 2013
THE PRIMARY ISSUE DURING THE NEXT 24 HOURS IS DETERMINING HOW HOT
WE ACTUALLY GET TODAY/HOW CLOSE WE GET TO HEAT ADVISORY
CRITERIA...AND HOW CLOSE TO CRITICAL FIRE DANGER WESTERN PARTS OF
NORTH CENTRAL KANSAS MIGHT GET. ALTHOUGH THE FORECAST PRODUCTS
CARRY NO MENTION OF SHOWERS/THUNDERSTORMS DUE TO POPS HOLDING BELOW
15 PERCENT...POPS ARE NOT NECESSARILY ZERO...AND WILL HAVE TO KEEP
AN EYE ESPECIALLY ON FAR WESTERN/NORTHERN COUNTIES LATE THIS
AFTERNOON-TONIGHT FOR THE REMOTE CHANCE THAT A FEW STORMS COULD
POP UP OR MOVE IN FROM THE WEST/NORTH. IN THE IMMEDIATE NEXT FEW
HOURS...ITS NOT COMPLETELY OUT OF THE QUESTION THAT A FEW HIGH-
BASED SHOWERS/STORMS COULD TRY DEVELOPING IN EASTERN ZONES BEFORE
SUNRISE.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS A FAIRLY ILL-DEFINED QUASI-
STATIONARY FRONT SNAKING FROM A 1000 MILLIBAR LOW IN NORTHWEST
SD...SOUTHWARD THROUGH WESTERN NEBRASKA INTO NORTHWEST/SOUTH CENTRAL
KS. OFF TO THE EAST...A 1019MB HIGH IS CENTERED NEAR THE IA/IL
BORDER. BETWEEN THE FRONT AND THE HIGH...FAIRLY STEADY SOUTH-
SOUTHEAST BREEZES OF 8-15 MPH WITH OCCASIONAL GUSTS OVER 20 ARE IN
PLACE ACROSS THE CWA EARLY THIS MORNING...WITH THESE BREEZES
EXPECTED TO HELP HOLD LOW TEMPS UP BETWEEN 69-74 IN MOST AREAS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A
FAIRLY EXPANSIVE MID/UPPER LEVEL RIDGE AXIS THAT HAS BUILT
NORTHEAST SINCE 24 HOURS AGO TO ENCOMPASS MUCH OF THE
CENTRAL/SOUTH CENTRAL CONUS. THE CENTER AXIS OF THIS RIDGE...AT
ROUGHLY 590 DECAMETER...RUNS FROM ROUGHLY THE LOCAL CWA ON THE
NORTHEAST EDGE...BACK SOUTHWESTWARD TOWARD THE NM/TX BORDER. WITH
THIS RIDGE AXIS NEARLY OVERHEAD...THE FLOW OVER THE CWA AT 500MB
IS FAIRLY LIGHT/VARIABLE...WHILE A BIT LOWER AT 700MB...THERE IS
MODEST WEST-SOUTHWEST FLOW. A NARROW ZONE OF THETA-E ADVECTION
ALONG A FAIRLY TIGHT 700MB MOISTURE GRADIENT HAS RESULTED IN A
SCATTERED ACCAS FIELD WITHIN ROUGHLY THE EASTERN 1/3 OF THE CWA
TONIGHT...AND RECENTLY THE FIRST FEW HINTS OF ISOLATED ELEVATED
SPRINKLES/LIGHT SHOWERS HAVE SHOWED UP ON RADAR WITHIN A FEW OF
OUR EASTERN COUNTIES.
STARTING WITH THE MOST IMMEDIATE ISSUE...WILL BE CLOSELY
MONITORING RADAR TRENDS IN EASTERN ZONES PRIOR TO SUNRISE TO SEE
WHETHER THE AFOREMENTIONED VERY ISOLATED CONVECTION CAN BE COVERED
WITH A SPRINKLE MENTION...OR MIGHT NEED SOMETHING MORE.
THE LATEST RAP HAS CAUGHT ONTO THIS DEVELOPMENT...AND SUGGESTS
THAT MAINLY OUR FAR EASTERN COUNTIES NEAR THE HWY 81 CORRIDOR
COULD CONTINUE TO SEE SOME OF THIS PRE-DAWN ACTIVITY...BUT THAT IT
SHOULD LARGELY BE DONE OR ADVECTED EAST OF THE CWA BY 7AM/12Z. PER
FORECAST SOUNDINGS...PARCELS ROOTED NEAR 700MB COULD POTENTIALLY
HAVE UP TO AROUND 400 J/KG MUCAPE AVAILABLE TO THEM...SO A BRIEF
FLARE UP OF NON-SEVERE THUNDERSTORMS IS NOT COMPLETELY OUT OF THE
QUESTION. FOR NOW...WILL ONLY MENTION ISOLATED SPRINKLES IN OUR
EASTERN FEW COLUMNS OF NEBRASKA COUNTIES THROUGH 12Z TO COVER
THINGS...PENDING ANY EVIDENCE OTHERWISE.
TURNING TO THE DAYTIME HOURS...THE MAIN STORY WILL BE A RETURN OF
LEGITIMATE SUMMER HEAT...BUT DOES NOT APPEAR TO BE HEADLINE-
WORTHY. IN THE MID/UPPER LEVELS...THE DOMINANT RIDGE AXIS WILL
CONTINUE TO EXPAND ACROSS THE CENTRAL PLAINS IN A SOUTHWEST-
NORTHEAST FASHION...WITH PARTS OF THE CWA ALIGNED ALMOST DIRECTLY
UNDER ITS CENTER AXIS. AT THE SURFACE...A FAIRLY SHARP TROUGH
AXIS WILL SET UP FROM FAR EASTERN CO ACROSS NORTHWEST NEB INTO
CENTRAL SD BY MID-LATE AFTERNOON...EXTENDING FROM A ROUGHLY 1000MB
LOW CENTERED NEAR THE CO/KS BORDER. THE LOCAL CWA WILL REMAIN IN
THE OPEN WARM SECTOR SOLIDLY SOUTHEAST OF THIS TROUGH AXIS...AND
THUS WILL SEE A CONTINUATION OF FAIRLY BREEZY SOUTH-SOUTHEAST
WINDS...WITH SUSTAINED SPEEDS MOST ALL AREAS 15-20 MPH AND GUSTS
25 TO POSSIBLY 30 MPH AT TIMES. AS FOR CONVECTIVE CHANCES...ASIDE
FROM ANY EARLY MORNING ACTIVITY IN THE EAST...THERE IS LITTLE IF
ANY RISK OF SHOWERS/STORMS TODAY AS WARM MID LEVEL TEMPS WITHIN
THE RIDGE AXIS SHOULD SERVE TO CAP THINGS OFF PRETTY SOLIDLY. ONE
OF THE ONLY POSSIBLE CAVEATS...AS DEPICTED BY THE LATEST RAP
RUNS...IS THAT STRONG HEATING AND VERY DEEP MIXING COULD POP A FEW
HIGH-BASED STORMS LATE IN THE AFTERNOON ALONG WESTERN PORTIONS OF
THE NEB/KS BORDER...WITH SOME OF THIS ACTIVITY POSSIBLY ADVECTING
EAST INTO THE DAWSON-FURNAS COUNTY CORRIDOR...BUT THE ODDS OF THIS
SEEM LOW ENOUGH TO STICK WITH SILENT 10 POPS FOR NOW...AS MOST
LATE AFTERNOON STORMS SHOULD FOCUS WELL TO OUR NORTHWEST ALONG THE
AFOREMENTIONED TROUGH AXIS. TEMP-WISE...BASED ON HOW HIGHS TURNED
OUT YESTERDAY...IT APPEARS THE NAM AND ASSOCIATED MET GUIDANCE HAS
BEEN A BIT AGGRESSIVE WITH THE HEAT...AND AS A RESULT...HAVE
SHAVED A FEW DEGREES OFF HIGHS TODAY IN MOST AREAS...USING VALUES
A BIT CLOSER TO GFS MAV GUIDANCE AND A MULTI-MODEL BLEND. THIS STILL
YIELDS A VERY TOASTY DAY WITH HIGHS RANGING FROM MID 90S NORTHEAST
...MID-UPPER 90S CENTRAL AND UPPER 90S TO AROUND 102 IN KS ZONES
AND NEAR THE STATE LINE. AS FOR DEWPOINTS...NOT EXPECTING A
DRAMATIC MIX-DOWN TODAY GIVEN THAT WINDS WILL BE MORE SOUTHERLY
VERSUS SOUTHWESTERLY...BUT NUDGED THEM DOWN A BIT ESPECIALLY IN
WESTERN ZONES...RANGING FROM UPPER 50S AT MID-AFTERNOON IN THE FAR
WEST TO MID-UPPER 60S IN THE EAST. THE RESULTANT HEAT INDEX VALUES
PEAK IN THE 98-100 RANGE ACROSS MOST OF THE NEB CWA...WITH KS
ZONES AND AREAS NEAR THE STATE LINE MORE LIKELY TO REACH THE
101-104 RANGE. BOTTOM LINE HERE IS...THESE VALUES ARE CERTAINLY
WORTH A HAZARDOUS WEATHER OUTLOOK MENTION...BUT DO NOT JUSTIFY A
FORMAL HEAT ADVISORY BASED ON OUR 105+ LOCAL CRITERIA. PLEASE NOTE
THAT THE NORTH PLATTE/LBF CWA HAS A SLIGHTLY COOLER
...CLIMATOLOGICALLY-BASED HEAT ADVISORY CRITERIA OF 100+...AND
THIS IS WHY A FORMAL HEADLINE IS OUT FOR THEIR AREA...BUT NOT FOR
OURS.
TURNING TO THIS EVENING/TONIGHT POST-7PM/00Z...THE MAIN STORY
VERSUS PREVIOUS FORECAST IS THAT THE SLIGHT CHANCE OF
THUNDERSTORMS HAS BEEN TRIMMED FROM THE EXTREME NORTHERN/WEST-
CENTRAL EDGES OF THE CWA...AND THUS WILL CARRY A STORM-FREE
FORECAST CWA-WIDE. AGAIN THOUGH...WILL EMPHASIZE THAT SILENT 10
POPS WILL REMAIN IN PLACE ESPECIALLY IN NORTHERN/WESTERN COUNTIES
TO AT LEAST ACKNOWLEDGE THAT A VERY LOW PROBABILITY OF SOME
ACTIVITY IS NOT COMPLETELY OUT OF THE QUESTION. IN THE MID-UPPER
LEVELS...THERE IS VERY LITTLE CHANGE WITH THE STRENGTH/ORIENTATION
OF THE EXPANSIVE RIDGE AXIS...AS IT REMAINS DRAPED FROM SOUTHWEST-
NORTHEAST ACROSS THE HEART OF THE CENTRAL PLAINS. A BIT LOWER AT
850MB...A 40+KT SOUTHERLY LOW LEVEL JET CRANKS UP THROUGH THE
NIGHT FROM WESTERN KS ACROSS CENTRAL NEB INTO EASTERN SD/WESTERN
MN...HELPING TO FOCUS THE VAST MAJORITY OF REGIONAL CONVECTION
NEAR THE EXIT REGION OF THIS FEATURE FROM NORTHEAST CO ACROSS
NORTHWEST NEB INTO SD/MN. AT THE SURFACE...THERE WILL ALSO BE
LITTLE OVERALL CHANGE FROM THE DAYTIME HOURS...WITH THE TROUGH
AXIS PERSISTING FROM NEAR THE KS/CO BORDER NORTH-NORTHEAST INTO
CENTRAL SD. WITH A CONTINUED MODEST PRESSURE GRADIENT AND LIMITED
MIXING UNDER THE LOW LEVEL JET...SURFACE BREEZES ACROSS THE CWA
WILL AGAIN AVERAGE 10-15 MPH FROM THE SOUTH-SOUTHEAST. ASSUMING
THAT POTENTIALLY ROGUE LATE AFTERNOON/EARLY EVENING STORMS DO NOT
AFFECT THE FAR WESTERN CWA...ITS PRETTY APPARENT FROM MOST MODEL
DEPICTIONS THAT OVERNIGHT CONVECTION SHOULD FOCUS AT LEAST 50-100
MILES NORTH THROUGH NORTHWEST OF THE CWA...AND GENERALLY LIFT
NORTH WITH TIME. THE ONLY FORESEEABLE CAVEAT HERE WOULD BE IF
NORTHERN NEB STORMS DEVELOP A COLD POOL AND START TO BUILD
SOUTHWARD INTO THE LOW LEVEL JET AXIS...POTENTIALLY REACHING THE
NORTHERN PARTS OF THE CWA. INTERESTINGLY...AT LEAST ONE
MODEL...THE 4KM WRF-NMM FROM PSU...DOES DEPICT THIS SCENARIO...BUT
GIVEN SUCH LIMITED SUPPORT WILL KEEP IT STORM-FREE FOR NOW. WILL
ALSO NOTE THAT THE 00Z GFS DEPICTION OF LATE NIGHT STORMS FLARING
UP NEAR HIGHWAY 81...LIKELY IN RESPONSE TO ANOTHER SUBTLE BATCH OF
MID LEVEL THETA-E ADVECTION...HAS BEEN DISREGARDED AS AN OUTLIER
AS WELL FOR THIS FORECAST. LOW TEMPERATURES WERE CHANGED
LITTLE...AND AGAIN REFLECT A SLIGHT UPWARD TREND FROM THE PAST FEW
NIGHTS...WITH MOST AREAS PROGGED TO BOTTOM OUT 72-75.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 431 AM CDT FRI JUL 12 2013
FOCUS FOR THIS TIMEFRAME WILL INVOLVE BOTH HIGH TEMPERATURES AND
PRECIPITATION CHANCES. MOST OF THE OPERATIONAL MODELS ARE COMING
INTO AGREEMENT ON THE UNUSUAL PATTERN EXPECTED IN THE SATURDAY TO
THURSDAY PERIOD. THEY ARE TAKING THE MID/UPPER LEVEL LOW PRESSURE
CURRENTLY SITTING OVER OHIO...AND RETROGRADING IT BACK TO THE
WEST. BY 12Z SAT THE GFS HAS IT OVER CENTRAL TENN...WHILE THE EC
PLACES IT A LITTLE NORTH OF THERE OVER KENTUCKY...AND THE NAM IS
BETWEEN THE TWO. BY 12Z SUNDAY THESE MODELS HAVE IT FROM CENTRAL
MISSOURI TO WESTERN ARKANSAS. THIS WESTWARD PUSH IS PROGGED TO
CONTINUE AND BY 12Z MONDAY IT IS FORECAST TO BE FROM NORTHERN
OKLAHOMA TO NORTHERN TEXAS. IT THEN APPEARS TO REMAIN OVER THE
TEXAS PANHANDLE OR IN NORTHEASTERN NEW MEXICO WHILE GRADUALLY
FILLING INTO THE WORKWEEK.
THIS IS NOT A VERY COMMON SCENARIO AND IF IT DOES COME TO FRUITION
WOULD MEAN COOLER TEMPERATURES STARTING SUNDAY. IN THE PAST 24
HRS...THE EXPECTED 850 MB TEMPS FOR SUNDAY OVER OUR AREA HAVE
DECREASED ABOUT 8-10 DEGREES C. GIVEN THE CONSISTENCY OF THE VARIOUS
OPERATIONAL MODELS WILL BUY INTO THIS SCENARIO AND LOWER HIGHS ON
SUNDAY BY SEVERAL DEGREES. SIMILAR TEMPERATURES CAN BE EXPECTED ON
MONDAY AND TUESDAY. WHILE COOLER THAN THOSE EXPECTED FOR TODAY AND
SATURDAY...WOULD NOT EXACTLY CALL IT COOL WEATHER AS HIGHS WILL
ACTUALLY BE AROUND NORMAL FOR THIS TIME OF YEAR FOR SUN-TUES. AFTER
THAT WE SHOULD SEE A GRADUAL WARMUP AS RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION.
PRECIPITATION CONTINUES TO BE DIFFICULT TO FORECAST. LOOKS LIKE
THERE ARE AT LEAST SLIGHT CHANCES ON SAT AND SUNDAY NIGHTS OVER MUCH
OF THE CWA WITH A SURFACE BOUNDARY JUST TO OUR WEST...WEAK WAVES
ROTATING JUST TO OUR NORTH ALONG THE NORTHERN JET...AND THE
APPROACHING RETROGRADING LOW MENTIONED ABOVE. WILL CONTINUE TO
FORECAST DRY WEATHER FOR THE UPCOMING WORKWEEK BUT THAT MAY CHANGE
DEPENDING HOW FAR NORTH THAT RETROGRADING LOW TRACKS. AT
PRESENT...IT MAY AFFECT THE KANSAS PART OF OUR CWA BUT THE FURTHER
NORTH ITS TRACK...THE BETTER THE CHANCE FOR SOME RAIN IN THE NEB
PART OF OUR CWA.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1259 AM CDT FRI JUL 12 2013
THERE IS FAIRLY HIGH CONFIDENCE THAT VFR CEILING/VISIBILITY WILL
PREVAIL THROUGH THE PERIOD...WITH MID/UPPER LEVEL HIGH PRESSURE
DOMINATING THE LOCAL WEATHER PATTERN AND PROVIDING MOSTLY CLEAR
SKIES...AND VERY LITTLE IF ANY RISK OF A SHOWER/THUNDERSTORM. AS
FOR SURFACE WINDS...A RATHER CONSTANT SOUTH-SOUTHEAST DIRECTION
WILL PREVAIL THROUGHOUT THE PERIOD...AND IT WILL REMAIN FAIRLY
BREEZY MOST OF THE TIME...WITH GUSTS COMMONLY UP TO AROUND
18KT...AND FRIDAY DAYTIME GUST POTENTIAL TO AT LEAST 25KT AT
TIMES. THE ONLY REAL ISSUE OF NOTE IS LOW LEVEL WIND SHEAR
UNDERNEATH A LOW LEVEL JET ALOFT. WILL CONTINUE A MENTION OF
SOMEWHAT MARGINAL LLWS THROUGH 14Z THIS MORNING...TO ACCOUNT FOR A
30+KT BULK SHEAR DIFFERENCE BETWEEN THE SURFACE AND APPROXIMATELY
1500 FT AGL...WHERE SUSTAINED SOUTHERLY WINDS UP TO AROUND 44KT
WILL RESIDE. ANOTHER ROUND OF LLWS COULD DEVELOP LATE FRIDAY
NIGHT...BUT THIS WILL MAINLY FALL WITHIN LATER FORECAST PERIODS.
&&
.FIRE WEATHER...
ISSUED AT 431 AM CDT FRI JUL 12 2013
ALTHOUGH CRITICAL FIRE WEATHER CONDITIONS/DANGER ARE NOT
ANTICIPATED WITHIN THE CWA TODAY...NEAR-CRITICAL CONDITIONS ARE
FORECAST ESPECIALLY IN THE FAR SOUTHWEST IN THE PHILLIPS/ROOKS
COUNTY AREAS...AND THUS WILL INTRODUCE THIS MENTION INTO THE
HAZARDOUS WEATHER OUTLOOK. THIS AREA WILL FEATURE THE GREATEST
OVERLAP OF SUSTAINED WINDS/GUSTS 20/25 MPH...AND RELATIVE HUMIDITY
VALUES NEAR OR SLIGHTLY BELOW 25 PERCENT. CERTAINLY...AT LEAST A
LIMITED FIRE DANGER WILL EXIST ELSEWHERE ACROSS THE CWA GIVEN THE
STEADY BREEZES AND OVERALL DRY CONDITIONS OF LATE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...EWALD
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1137 PM MDT THU JUL 11 2013
.AVIATION...
06Z TAF CYCLE
MAIN UPPER HIGH CENTER TO SHIFT SLOWLY INTO THE CENTRAL HIGH
PLAINS NEXT 24 HOURS. OUTFLOW BOUNDARY FROM CONVECTION OVER THE
JEMEZ MTS HAS SPAWNED ADDITIONAL CONVECTION INTO THE MIDDLE
RGV...WHICH MAY PERSIST UNTIL AROUND D8Z. ISOLD BUT HEAVY RAIN
MAY RESULT IN LOCALIZED MVFR TO BRIEFLY IFR CIGS/VSBYS AND MT
OBSCURATIONS.
&&
.PREV DISCUSSION...1107 PM MDT THU JUL 11 2013...
MUCH OF THE CONVECTION HAS DIMINISHED THESE EVENING EXCEPT IN THE
VICINITY OF THE JEMEZ MOUNTAINS. AN OUTFLOW BOUNDARY ORIGINATING
FROM THESE STORMS HAS PUSHED OUTWARD TOWARD SANTA FE AND
ALBUQUERQUE. ADDITIONAL STORM DEVELOPMENT IS LIKELY ALONG THIS
BOUNDARY...AND THE LATEST HRRR SUPPORTS THIS WELL. THE NAM AND TO
SOME EXTENT THE HRRR...HAVE A BATCH OF STORMS MOVING UP INTO THE
SOUTHWEST MOUNTAINS LATE TONIGHT AS WELL. UPDATED POP GRIDS FOR
THE OVERNIGHT PERIOD. NO OTHER CHANGES MADE ATTM. UPDATES OUT
SHORTLY.
34
&&
.
&&
.PREV DISCUSSION...300 PM MDT THU JUL 11 2013...
WEAK SOUTHERLY LOW LEVEL FLOW WITH COPIOUS MOISTURE IN PLACE AS
EVIDENCED BY THE MORNING CLOUDINESS AND OVERNIGHT WEAK MCS THAT
PERSISTED INTO THE EARLY MORNING HOURS ACROSS EAST CENTRAL PLAINS
AND A 12Z KABQ PWAT VALUE AT 1.26 INCHES. EXPECT SLOW GENERALLY
SOUTH TO NORTH NORTHEAST STORM MOTIONS AND HEAVY PRECIPITATION
POTENTIALS ACROSS THE FORECAST AREA THIS AFTERNOON AND EVENING.
THE 592H5 UPPER HIGH IS DRIFTING NE TOWARDS THE TX-OK PANHANDLES
BY TOMORROW AFTERNOON. AS THE HIGH DRIFTS TO THE NE THIS WILL
GENERALLY ENHANCE OUR SOUTHERLY FLOW ESPECIALLY ACROSS THE WESTERN
MOUNTAINS. AS A RESULT THE FOCUS FOR STORMS AND PRECIPITATION WILL
SHIFT TOWARDS AREAS WEST OF THE RIO GRANDE AND ESPECIALLY THE
WESTERN MOUNTAINS OVER THE WEEKEND.
EARLY NEXT WEEK FORECAST CONFIDENCE IS LOW AT THIS TIME BECAUSE THE
LONG RANGE MODELS ARE HAVING A DIFFICULT TIME WITH A HIGHLY UNUSUAL
PATTERN OF AN UPPER LOW RETROGRADING FROM THE OHIO RIVER VALLEY
TOWARDS TX PANHANDLE BY MONDAY AFTERNOON AS A VERY STRONG 598H5
UPPER HIGH BUILDS OVER OHIO-INDIANA. AN UPPER LOW WOULD BRING
ADDITIONAL INSTABILITY AND MOISTURE TO OUR FORECAST AREA CAUSING
PRECIPITATION CHANCES TO INCREASE FOR NEXT WEEK. WILL HAVE AWAIT
MORE IMPROVED MODEL CONSENSUS OR BETTER RUN-TO-RUN CONSISTENCY TO
PROVIDE MORE PRECISE FORECAST DETAILS. FOR NOW...FOR THE EARLY TO
MIDDLE OF NEXT WEEK...EXPECT SEASONAL POPS AROUND 10 TO 30 PERCENT
WITH STORMS INITIATING OVER HIGHER TERRAIN EARLY THEN AFFECTING
PLAINS AND VALLEYS BY LATE AFTERNOON AND EVENING. IF THIS UPPER LOW
AFFECTS THE AREA POPS WILL INCREASE.
BENNETT
&&
.FIRE WEATHER...
CONVECTION HAS BEEN A BIT SLOWER TO START TODAY DUE TO LINGERING MID
LEVEL CLOUDS FROM THE OVERNIGHT CONVECTION. NONETHELESS...SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AND
EVENING AS INSTABILITY INCREASES WITH DAYTIME HEATING. SHOWERS AND
STORMS WILL FAVOR AREAS ALONG AND WEST OF THE CENTRAL MOUNTAIN
CHAIN. PRECIPITABLE WATER VALUES EARLY THIS AFTERNOON PER SATELLITE
IMAGERY CONTINUE TO SHOW ABOVE NORMAL VALUES FOR MID JULY...THUS
HEAVY RAINFALL IS POSSIBLE JUST ABOUT ANYWHERE. FORTUNATELY...STORMS
ARE MOVING A BIT FASTER THAN IN RECENT DAYS...WHICH WILL HELP
MITIGATE EXCESSIVE RAINFALL TOTALS.
ON FRIDAY...THE UPPER HIGH ELONGATES NORTHEASTWARD...WITH THE CENTER
OF THE HIGH OVER KANSAS. THOUGH THE RIDGE AXIS EXTENDS BACK INTO SC
NM...THERE SHOULD BE SOME CONTINUED MONSOONAL MOISTURE TRANSPORT
INTO CENTRAL AND WESTERN NM. THUS...EXPECT IT TO REMAIN ACTIVE OVER
THE HIGH TERRAIN...WITH STEERING FLOW SIMILAR TO...OR SLIGHTLY LESS
THAN...TODAY.
THE UPPER LEVEL HIGH WILL BUILD BACK TO THE WEST ON SATURDAY...AND
AN AREA OF DRIER AIR/SUBSIDENCE WILL MOVE INTO THE SOUTHEAST HALF OR
SO OF THE FORECAST AREA. CONVECTIVE COVERAGE WILL BE DOWN
OVERALL...BUT SCATTERED STORMS WILL REMAIN POSSIBLE ACROSS THE
NORTHERN MOUNTAINS AND WESTERN HIGH TERRAIN. STEERING FLOW WILL BE
LIGHTER...THUS EXPECT SLOWER STORM MOTIONS.
THE UPPER HIGH WILL CONTINUE TO BUILD WESTWARD ON SUNDAY...OVER
NORTH CENTRAL NM...AND THE AREA OF DRY AIR WILL CONTINUE TO MOVE
WESTWARD AS WELL. THIS COMBINATION WILL LIMIT CONVECTION FURTHER.
OTHERWISE...LITTLE DAY TO DAY CHANGE WITH HUMIDITIES ARE
EXPECTED...THOUGH SUNDAY WILL BE THE DRIEST DAY OVERALL. AN AREA OF
POOR TO FAIR VENTILATION IS EXPECTED ON FRIDAY FROM THE WEST CENTRAL
HIGHLANDS NORTHEAST TO THE NORTHERN MTNS...THOUGH GOOD TO EXCELLENT
VENTILATION IS EXPECTED ELSEWHERE. ON SATURDAY...POOR TO FAIR
VENTILATION WILL FAVOR THE NORTHWEST QUARTER OF THE STATE.
HOWEVER...BY SUNDAY...GOOD VENTILATION OR BETTER IS EXPECTED ACROSS
MOST AREAS AS MIXING HEIGHTS INCREASE.
THE MODELS CONTINUE TO STRUGGLE WITH THE EARLY WEEK PATTERN. LATEST
RUNS HAVE THE HIGH RETREATING FURTHER WESTWARD AS AN EASTERLY WAVE
SLOWLY SLIDES INTO NORTHEAST NM. IF THIS OCCURS...MUCH OF NEXT WEEK
COULD BE WET. HOWEVER...GIVEN THAT THIS IS A HIGHLY UNUSUAL
PATTERN...AND MODELS ARE WAFFLING A BIT...CONFIDENCE IS MODERATE TO
LOW ON THIS SCENARIO.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1107 PM MDT THU JUL 11 2013
.UPDATE...
MUCH OF THE CONVECTION HAS DIMINISHED THESE EVENING EXCEPT IN THE
VICINITY OF THE JEMEZ MOUNTAINS. AN OUTFLOW BOUNDARY ORIGINATING
FROM THESE STORMS HAS PUSHED OUTWARD TOWARD SANTA FE AND
ALBUQUERQUE. ADDITIONAL STORM DEVELOPMENT IS LIKELY ALONG THIS
BOUNDARY...AND THE LATEST HRRR SUPPORTS THIS WELL. THE NAM AND TO
SOME EXTENT THE HRRR...HAVE A BATCH OF STORMS MOVING UP INTO THE
SOUTHWEST MOUNTAINS LATE TONIGHT AS WELL. UPDATED POP GRIDS FOR
THE OVERNIGHT PERIOD. NO OTHER CHANGES MADE ATTM. UPDATES OUT
SHORTLY.
34
&&
.PREV DISCUSSION...542 PM MDT THU JUL 11 2013...
.AVIATION...
00Z TAF CYCLE
WITH THE UPPER HIGH CENTERED MORE OR LESS OVER NORTHEAST NEW
MEXICO...STEERING FLOWS WILL REMAIN RELATIVELY LIGHT...WITH CELLS
MOVING TO THE NORTH AND NORTHWEST OVER WRN NM AND MORE ERRATIC
MOVEMENT ELSEWHERE. ATMOSPHERIC MOISTURE IS HIGH AND SHOWERS AND
STORMS COULD PRODUCE LOCALLY HEAVY RAIN RESULTING IN MVFR TO
BRIEFLY IFR CIGS/VSBYS AND MT OBSCURATIONS. GUSTY OUTFLOWS OF 35KT
TO 40KT ARE EXPECTED AS WELL. CONVECTION TO SLOWLY DIMINISH
BETWEEN 06Z TO 09Z ALTHOUGH LINGERING SHRA ARE POSSIBLE.
300 PM MDT THU JUL 11 2013...
WEAK SOUTHERLY LOW LEVEL FLOW WITH COPIOUS MOISTURE IN PLACE AS
EVIDENCED BY THE MORNING CLOUDINESS AND OVERNIGHT WEAK MCS THAT
PERSISTED INTO THE EARLY MORNING HOURS ACROSS EAST CENTRAL PLAINS
AND A 12Z KABQ PWAT VALUE AT 1.26 INCHES. EXPECT SLOW GENERALLY
SOUTH TO NORTH NORTHEAST STORM MOTIONS AND HEAVY PRECIPITATION
POTENTIALS ACROSS THE FORECAST AREA THIS AFTERNOON AND EVENING.
THE 592H5 UPPER HIGH IS DRIFTING NE TOWARDS THE TX-OK PANHANDLES
BY TOMORROW AFTERNOON. AS THE HIGH DRIFTS TO THE NE THIS WILL
GENERALLY ENHANCE OUR SOUTHERLY FLOW ESPECIALLY ACROSS THE WESTERN
MOUNTAINS. AS A RESULT THE FOCUS FOR STORMS AND PRECIPITATION WILL
SHIFT TOWARDS AREAS WEST OF THE RIO GRANDE AND ESPECIALLY THE
WESTERN MOUNTAINS OVER THE WEEKEND.
EARLY NEXT WEEK FORECAST CONFIDENCE IS LOW AT THIS TIME BECAUSE THE
LONG RANGE MODELS ARE HAVING A DIFFICULT TIME WITH A HIGHLY UNUSUAL
PATTERN OF AN UPPER LOW RETROGRADING FROM THE OHIO RIVER VALLEY
TOWARDS TX PANHANDLE BY MONDAY AFTERNOON AS A VERY STRONG 598H5
UPPER HIGH BUILDS OVER OHIO-INDIANA. AN UPPER LOW WOULD BRING
ADDITIONAL INSTABILITY AND MOISTURE TO OUR FORECAST AREA CAUSING
PRECIPITATION CHANCES TO INCREASE FOR NEXT WEEK. WILL HAVE AWAIT
MORE IMPROVED MODEL CONSENSUS OR BETTER RUN-TO-RUN CONSISTENCY TO
PROVIDE MORE PRECISE FORECAST DETAILS. FOR NOW...FOR THE EARLY TO
MIDDLE OF NEXT WEEK...EXPECT SEASONAL POPS AROUND 10 TO 30 PERCENT
WITH STORMS INITIATING OVER HIGHER TERRAIN EARLY THEN AFFECTING
PLAINS AND VALLEYS BY LATE AFTERNOON AND EVENING. IF THIS UPPER LOW
AFFECTS THE AREA POPS WILL INCREASE.
BENNETT
.FIRE WEATHER...
CONVECTION HAS BEEN A BIT SLOWER TO START TODAY DUE TO LINGERING MID
LEVEL CLOUDS FROM THE OVERNIGHT CONVECTION. NONETHELESS...SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AND
EVENING AS INSTABILITY INCREASES WITH DAYTIME HEATING. SHOWERS AND
STORMS WILL FAVOR AREAS ALONG AND WEST OF THE CENTRAL MOUNTAIN
CHAIN. PRECIPITABLE WATER VALUES EARLY THIS AFTERNOON PER SATELLITE
IMAGERY CONTINUE TO SHOW ABOVE NORMAL VALUES FOR MID JULY...THUS
HEAVY RAINFALL IS POSSIBLE JUST ABOUT ANYWHERE. FORTUNATELY...STORMS
ARE MOVING A BIT FASTER THAN IN RECENT DAYS...WHICH WILL HELP
MITIGATE EXCESSIVE RAINFALL TOTALS.
ON FRIDAY...THE UPPER HIGH ELONGATES NORTHEASTWARD...WITH THE CENTER
OF THE HIGH OVER KANSAS. THOUGH THE RIDGE AXIS EXTENDS BACK INTO SC
NM...THERE SHOULD BE SOME CONTINUED MONSOONAL MOISTURE TRANSPORT
INTO CENTRAL AND WESTERN NM. THUS...EXPECT IT TO REMAIN ACTIVE OVER
THE HIGH TERRAIN...WITH STEERING FLOW SIMILAR TO...OR SLIGHTLY LESS
THAN...TODAY.
THE UPPER LEVEL HIGH WILL BUILD BACK TO THE WEST ON SATURDAY...AND
AN AREA OF DRIER AIR/SUBSIDENCE WILL MOVE INTO THE SOUTHEAST HALF OR
SO OF THE FORECAST AREA. CONVECTIVE COVERAGE WILL BE DOWN
OVERALL...BUT SCATTERED STORMS WILL REMAIN POSSIBLE ACROSS THE
NORTHERN MOUNTAINS AND WESTERN HIGH TERRAIN. STEERING FLOW WILL BE
LIGHTER...THUS EXPECT SLOWER STORM MOTIONS.
THE UPPER HIGH WILL CONTINUE TO BUILD WESTWARD ON SUNDAY...OVER
NORTH CENTRAL NM...AND THE AREA OF DRY AIR WILL CONTINUE TO MOVE
WESTWARD AS WELL. THIS COMBINATION WILL LIMIT CONVECTION FURTHER.
OTHERWISE...LITTLE DAY TO DAY CHANGE WITH HUMIDITIES ARE
EXPECTED...THOUGH SUNDAY WILL BE THE DRIEST DAY OVERALL. AN AREA OF
POOR TO FAIR VENTILATION IS EXPECTED ON FRIDAY FROM THE WEST CENTRAL
HIGHLANDS NORTHEAST TO THE NORTHERN MTNS...THOUGH GOOD TO EXCELLENT
VENTILATION IS EXPECTED ELSEWHERE. ON SATURDAY...POOR TO FAIR
VENTILATION WILL FAVOR THE NORTHWEST QUARTER OF THE STATE.
HOWEVER...BY SUNDAY...GOOD VENTILATION OR BETTER IS EXPECTED ACROSS
MOST AREAS AS MIXING HEIGHTS INCREASE.
THE MODELS CONTINUE TO STRUGGLE WITH THE EARLY WEEK PATTERN. LATEST
RUNS HAVE THE HIGH RETREATING FURTHER WESTWARD AS AN EASTERLY WAVE
SLOWLY SLIDES INTO NORTHEAST NM. IF THIS OCCURS...MUCH OF NEXT WEEK
COULD BE WET. HOWEVER...GIVEN THAT THIS IS A HIGHLY UNUSUAL
PATTERN...AND MODELS ARE WAFFLING A BIT...CONFIDENCE IS MODERATE TO
LOW ON THIS SCENARIO.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
806 PM EDT SAT JUL 13 2013
.SYNOPSIS...
A WEAK WARM FRONT OVER THE REGION WILL MOVE WEST AND DISSIPATE
TONIGHT. HIGH PRESSURE BUILDING IN FROM THE NORTHEAST WILL BRING
DRIER WEATHER AND A TREND TOWARD HOTTER TEMPERATURES FROM SUNDAY
THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM SATURDAY...
LATEST SFC ANALYSIS SHOWS THE WEAK SFC FRONT JUST WEST OF THE I-95
CORRIDOR AND GRADUALLY MOVING WEST. SCATTERED SHOWERS WITH A FEW
EMBEDDED TSTMS CONTINUE ACROSS THE COASTAL PLAIN AND EASTERN
PIEDMONT...AND EXPECT THIS ACTIVITY TO CONTINUE TO GRADUALLY MOVE
WEST AND WEAKEN AS IT APPROACHES THE TRIAD...WHERE THE LATEST
MESOANALYSIS SHOWS LESS THAN 500J/KG MLCAPE. LATEST HRRR AND TO SOME
EXTENT THE WRF ARW WANT TO TAKE THIS ACTIVITY AND PUSH IT WEST
ACROSS THE TRIAD LATE THIS AFTERNOON. WHILE THIS STILL MAY
HAPPEN...THE CURRENT THERMODYNAMIC PROFILE SUGGESTS THAT IT SHOULD
BE FAIRLY MODEST INTENSITY IF IT OCCURS.
IN THE BIGGER PICTURE...THE CLOSED LOW OVER WRN KY APPEARS TO BE
PICKING UP SOME SPEED IN ITS WWD MOVEMENT...AND IS PROGGED TO BE
OVER MO BY 06Z TONIGHT. MEANWHILE...THE RIDGE OVER NEW ENGLAND IS
PROGGED TO BUILD SOUTH AND WEST ACROSS THE MID ATLANTIC DURING THIS
TIME. THE NET EFFECT FOR US IS THAT THE CURRENT AIRMASS
CHARACTERIZED BY 2+INCHES OF PWAT SHOULD FINALLY BEGIN TO MOVE WEST
OF OUR CWA AND ALLOW SOME DRIER AIR TO OUR E AND NE (AS CURRENTLY
SEEN ON WATER VAPOR AND IN THE BLENDED TPW PRODUCT) TO MOVE INTO OUR
AREA. MOST CAMS THUS SHOW RAIN ENDING ACROSS OUR CWA AROUND OR
SHORTLY AFTER 00Z THIS EVENING. DESPITE NOTEWORTHY DRYING ABOVE
H8...GUIDANCE CONTINUES TO SHOW THE LOW LEVEL AIRMASS REMAINING
QUITE MOIST (AS INDICATED BY PERSISTENT 70F DWPTS)...THUS LOOK FOR
ANOTHER NIGHT OF LOW CLOUDS AND PERHAPS SOME FOG SETTING UP BETWEEN
03Z-06Z AND LINGERING THROUGH SUNRISE. PERSISTENCE FOR LOWS...AROUND
70 FOR MOST CENTRAL NC LOCALES.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 235 PM SATURDAY...
THE RIDGE CENTERED OVER PA SUNDAY MORNING WILL BE THE PRIMARY...AND
MUCH ANTICIPATED INFLUENCE ON OUR WEATHER THROUGH THE SHORT TERM
PERIOD. THE DRYING TREND WILL ALREADY BE UNDERWAY AT THE START OF
THE PERIOD AND SHOULD CONTINUE THROUGH SUNDAY...BUT PRIMARILY ABOVE
THE BOUNDARY LAYER. AS SUCH...LOOK FOR SOME SUNSHINE IN THE
MORNING...FOLLOWING BY BUILDING CU IN THE AFTERNOON AS THE DAYTIME
HEATING PROGRESSES. FORECAST SOUNDINGS SUGGEST THAT THE CU MAY BUILD
ENOUGH TO SUPPORT A FEW SHOWERS AND PERHAPS AN ISOLD TSTM...THUS
WILL CARRY POPS OF 15-20 PERCENT (HIGHEST WEST) TO COVER THIS
POSSIBILITY. HOWEVER THIS IS STILL BELOW OUR CLIMATOLOGICAL POP FOR
THIS TIME OF YEAR. THICKNESSES AND FORECAST SOUNDINGS SUGGEST HIGHS
IN THE UPPER 80S TO NEAR 90.
FOR SUNDAY NIGHT...WITH SFC DPWTS STILL LINGERING AROUND 70...CAN`T
RULE OUT SOME FOG OR EVEN SOME LOW STRATUS EARLY MONDAY MORNING...
BUT SHOULDN`T BE AS WIDESPREAD AS PREV NIGHTS. LOWS IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 257 PM SATURDAY...
UPPER LEVEL LOW PRESSURE CENTER MOVES OVER TX ON MONDAY... WITH
UPPER LEVEL RIDGING OVER THE MIDATLANTIC. THE RIDGE BECOMES QUITE
FLATTENED TUESDAY INTO WEDNESDAY... WITH A LARGE AREA OF LOW
PRESSURE NEAR THE HUDSON BAY AREA OF CANADA AND SEVERAL SHORTWAVE
IMPULSES BEING DRIVEN ALONG THE NORTHERN PERIPHERY OF THE RIDGE. THE
PIEDMONT TROUGH BECOMES MORE PRONOUNCED LATE IN THE WEEK... AND WITH
PWS ONCE AGAIN INCREASING TO AROUND 2 INCHES... WILL SUPPORT
ENHANCED DIURNAL CONVECTION. SHEAR REMAINS WEAK... AND DYNAMIC
FORCING REMAINS WELL TO THE NORTH... RESULTING IN GENERAL PULSE TYPE
CONVECTION. LOW LEVEL THICKNESSES TREND ABOVE NORMAL THROUGH THE
WEEK... AND ACCORDINGLY... HIGHS A FEW DEGREES ABOVE NORMAL AT
AROUND 90 TO START THE WEEK... AND INTO THE LOWER 90S BY WEEKS END.
WITH DEWPOINTS IN THE 70S... HEAT INDEX WILL REACH NEAR 100 DEGREES.
LOWS IN THE LOWER 70S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 750 PM SATURDAY...
CURRENTLY...A WEAKENING BOUNDARY ROUGHLY BISECTS THE FORECAST AREA
FROM NORTHEAST TO SOUTHWEST. PRECIP THAT FORMED NEAR THIS BOUNDARY
EARLIER THIS AFTERNOON HAS MOSTLY DISSIPATED...WITH ONLY A FEW LIGHT
SHOWERS LINGERING ACROSS THE EAST. SOME BREAKS IN THE CLOUDS HAVE
DEVELOPED THIS EVENING...WITH CIGS RANGING FROM HIGH END MVFR TO VFR
AREAWIDE. HOWEVER...LOW LEVEL MOISTURE WILL REMAIN HIGH TONIGHT AND
THEREFORE ANOTHER NIGHT OF WIDESPREAD IFR/LIFR CONDITIONS DUE TO LOW
STRATUS/PATCHY FOG IS EXPECTED. HIGH PRESSURE WILL BUILD OVER THE
AREA ON SUNDAY...BRINGING WITH IT MUCH DRIER AIR (ESPECIALLY ALOFT)
AND THEREFORE CLOUDS SHOULD LIFT TO VFR EARLIER THAN PREVIOUS
DAYS...GENERALLY BETWEEN 15-18Z. ALTHOUGH MOSTLY DRY CONDITIONS ARE
EXPECTED ON SUNDAY...AN ISOLATED SHOWER OR TWO WILL BE POSSIBLE.
OUTLOOK...PATCHY MVFR/IFR CIGS ARE POSSIBLE LATE SUNDAY NIGHT INTO
MONDAY MORNING...OTHERWISE CONDITIONS ARE LIKELY TO REMAIN MOSTLY
VFR THROUGH THURSDAY AS HIGH PRESSURE REMAINS IN CONTROL OF THE
WEATHER ACROSS CENTRAL NC.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NP
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...SEC
AVIATION...KRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
948 AM EDT FRI JUL 12 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY MOVE IN FROM THE NORTHWEST TONIGHT AND
BECOME STATIONARY OVER EASTERN NORTH CAROLINA. THE FRONT WILL
DISSIPATE ON SUNDAY. A TROF OF LOW PRESSURE WILL PASS THROUGH
FROM THE EAST ON MONDAY. A TROF OF LOW PRESSURE WILL DEVELOP ALONG
THE COASTAL PLAIN WEDNESDAY AND CONTINUE INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 945 AM FRI...AREA OF MODERATE TO HEAVY RAIN W/EMBEDDED THUNDER
OVER SOUTHEAST NC AND ADJACENT WATERS IS MOVING NORTHEAST AND WILL
AFFECT THE FORECAST AREA IN THE NEXT FEW HOURS. RUC HOURLY
ANALYSIS SHOWS THIS AREA BEING DRIVEN BY A WELL-DEFINED VORT LOBE
OVER SE NC/NE SC. AREA ALSO UNDERNEATH RIGHT REAR QUAD OF UPPER
JET. WILL MAINTAIN LIKELY TO CATEGORICAL POPS THROUGH TODAY. TEMPS
WILL ONLY REACH THE LOW 80S DUE TO THE WIDESPREAD CLOUDS/PRECIP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 330 AM FRI...CONTINUING WET WEATHER FOR THIS EVENING... WITH
BEST PRECIP CHANCES TRANSITIONING TO THE COAST FOR THE OVERNIGHT.
QPF AMOUNTS LOOK TO BE LOWER AS BEST UPPER FORCING RETREATS AWAY
FROM THE REGION. WILL KEEP HEAVY RAIN MENTION OUT OF GRIDS THOUGH
WITH ANY EMBEDDED THUNDERSTORMS SOME AREAS WILL RECEIVE LOCALLY
HEAVIER RAIN.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 230 AM FRI...DEEP MOISTURE WILL CONT OVER THE REGION EARLY
SAT WITH HIGH CHC TO LIKELY POPS ALL AREAS. LATER SAT THE UPR LOW
TO THE W WILL CONT TO SHIFT FURTHER W AND DRIER AIR WILL BEGIN TO
WORK IN ESPCLY ALONG THE CST AND EXPECT PRECIP TO DIMINISH FOR ALL
BUT DEEP INLAND AREAS. RIDGE WILL THEN GRAD BUILD IN FROM THE NNE
SUN INTO EARLY NEXT WEEK WITH MAINLY DIURNAL PRECIP WITH BEST CHCS
INLAND DURING AFTN AND EVENING.
MID TO LATE WEEK THE UPR RDG WILL BUILD TO OUR WEST WITH PRECIP
CONFINED MAINLY TO THE SEA BRZ DURING THE AFTN AND EVENING INLAND.
TEMPS WILL HOLD IN THE 80S SAT THEN WITH MORE SUN REACH AROUND 90
INLAND SUN AND MON WITH LOWER 90S TUE THRU THU. MUGGY LOWS MAINLY
IN THE 70S WILL PERSIST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /TODAY AND TONIGHT/
AS OF 945 AM FRI...PERIODS OF RAIN AND OCNL THUNDER EXPECTED THROUGH
THE TAF PERIOD. CIGS WILL GENERALLY BE MVFR THOUGH WITH HEAVY
SHOWERS DIP DOWN TO IFR ALONG WITH LOWERED VSBYS. WINDS WILL BE
LIGHT FOR THIS TAF PERIOD.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 215 AM FRI...DECENT CVRG OF SHRA AND TSRA SAT ESPCLY EARLY
WITH SUB VFR LIKELY AT TIMES. MAINLY VFR DURING THE DAY AND
EVENING HOURS FROM SAT NIGHT ON AS RDG BUILDS TO THE N WITH DRIER
AIR SPREADING OVER THE REGION. AS USUAL WITH MOIST LOW LVL AND
RATHER LIGHT WINDS WILL LIKELY HAVE TYPICAL LATE NIGHT EARLY MORN
FOG AND STRATUS WITH AREAS OF REDUCED CIGS AND VSBYS AT TIMES.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/
AS OF 945 AM FRI...PRESENTLY WINDS ARE S TO SW 10 KNOTS OR LESS
ACROSS THE MARINE AREA. EXPECT WINDS TO INCREASE THIS AFTERNOON TO
CURRENTLY FORECAST LEVELS...SO DO NOT PLAN ANY CHANGES TO CURRENT
ZONES. WINDS WILL BACK SOUTH AND THEN SE TONIGHT AS HIGH PRES
BEGINS TO INFLUENCE THE COASTAL WATERS FROM THE NORTHEAST.
LONG TERM /SAT THROUGH TUESDAY/...
AS OF 215 AM FRI...MDLS SIMILAR SAT SHOWING DECENT GRDNT OVER AREA
BETWEEN HIGH TO THE N AND LOW TO THE SW. EXPECT SSE WINDS 15 TO 20
KTS AND SEAS 4 TO 6 FEET...HIGHEST OUTER CNTRL/SRN WATERS. AS THE
HIGH GRAD BUILDS SOUTH TWRD THE REGION SUN WINDS WILL BECOME E
LESS THAN 15 KTS WITH SEAS SUBSIDING TO 2 TO 3 FEET BY LATE
SUNDAY. THE HIGH WILL REMAIN NEAR THE AREA MON AND TUE WITH LIGHT
WINDS AND SEAS MAINLY 2 TOM 3 FEET...WITH POSS SOME 4 FOOTERS
OUTER WTRS MON.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR NCZ029-044>047-
079>081-090>095-098-103-104.
MARINE...NONE.
&&
$$
SYNOPSIS...TL
NEAR TERM...HSA/TL
SHORT TERM...TL
LONG TERM...RF
AVIATION...HSA/TL/RF
MARINE...HSA/TL/RF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1016 PM CDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 1012 PM CDT SAT JUL 13 2013
WELL GOT TO SAY...HRRR WAS THE ONLY MODEL WHICH HAD THE CONVECTION
IN WRN ND MOVE EAST TO BE IN ITS PRESENT LOCATION WHICH IS NR
LANGDON-DVL-BIS... IT HAS IT MOVING EAST AND REACHING THE GFK AREA
NR 06Z THEN WEAKENING. SPC PARAMETERS SO DCAPE PRETTY WEAK IN THE
NRN VALLEY WITH HIGHEST EAST OF CELL NR MORRIS MANITOBA. THUS DO
EXPECT ANY SEVERE LEVEL WIND GUSTS TO BE LESS AND LESS LIKELY. BUT
DID INCREASE POPS FOR LINE MOVING EAST. AS FOR STORMS IN WCNTRL MN
LOOKS LIKE VERY LATE PER HRRR AND NOT TOO STRONG IN TERMS OF RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 302 PM CDT SAT JUL 13 2013
CONVECTION CHANCES WILL CONTINUE TO BE THE FORECAST PROBLEM FOR
THE SHORT TERM.
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE ACROSS THE NORTHERN PLAINS
FOR THE SHORT TERM AS A CUT OFF LOW RETROGRADES WELL TO OUR SOUTH
AND UPPER RIDGING CONTINUES OVER THE CENTRAL PLAINS. SFC TROUGH
AXIS/FRONTAL BOUNDARY THAT STALLED OVER THE SOUTHEASTERN CWA HAS
STARTED TO WASH OUT...AND HUMID CONDITIONS CONTINUE ACROSS MOST OF
THE CWA. CAPE VALUES HAVE TOPPED 2000 J/KG ACROSS MOST OF THE
CWA...BUT THERE HAS BEEN LITTLE TO NO UPPER LEVEL SUPPORT TO SET
OFF STORMS. THINK THAT THE BEST CHANCES WILL BE LATER TONIGHT AS
SEVERAL UPPER LEVEL SHORTWAVES APPROACH THE AREA.
THE MAIN UPPER SHORTWAVE WILL LIFT OFF TO OUR NORTH INTO CANADA
AND MOST OF THE ACTIVITY WILL BE IN THAT AREA...ALTHOUGH OUR
NORTHWESTERN COUNTIES COULD GET CLIPPED AS A WEAK COLD FRONT
BEGINS TO MOVE IN SO KEPT SOME LOW POPS IN THAT AREA. A MORE MINOR
SHORTWAVE CURRENTLY OVER THE GREAT BASIN WILL MOVE INTO THE
DAKOTAS LATER TONIGHT. THINK THAT AS THIS FEATURE INTERSECTS THE
WASHED OUT BOUNDARY AND RICH MOISTURE IN THE SOUTHEASTERN
COUNTIES...THERE COULD BE THUNDERSTORMS DEVELOPING. AT THIS POINT
THINK THAT THE BEST INSTABILITY WILL NOT COINCIDE WITH THE BEST
BULK SHEAR SO A LOT OF SEVERE IS NOT EXPECTED. HOWEVER...WITH PWAT
VALUES CLOSE TO 2 INCHES IN OUR SOUTHEAST THERE COULD BE SOME
HEAVY RAIN POTENTIAL.
SUNDAY...THE NEXT SFC FRONT AGAIN MOVES INTO THE SOUTHEASTERN
COUNTIES AND BEGINS TO WASH OUT. CONTINUED TO KEEP FAIRLY HIGH
POPS IN OUR SOUTHEASTERN COUNTIES. THE FRONT SHOULD ALSO HELP
KNOCK BACK TEMPS AND DEW POINTS A BIT FOR TOMORROW AFTERNOON. THE
OLD SFC BOUNDARY WILL CONTINUE TO WOBBLE OVER MAINLY OUR SOUTHERN
COUNTIES THROUGH SUNDAY NIGHT AND WITH THE POSSIBILITY OF ANOTHER
WEAK SHORTWAVE COMING IN...MODELS ALL HAVE PRECIP OVER THE AREA
AND WILL KEEP POPS PRETTY HIGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 320 PM CDT SAT JUL 13 2013
MONDAY AND TUESDAY...SOUTHWESTERLY FLOW ALOFT CONTINUES WITH
ANOTHER SHORTWAVE MOVING THROUGH SOUTHERN CANADA. A SFC TROUGH
DEVELOPING OVER THE NORTHERN ROCKIES ON MONDAY WILL HELP PUSH WARM
MOIST AIR BACK INTO THE CWA. HOWEVER...700MB TEMPS WILL ALSO BE ON
THE RISE SO WILL KEEP POPS IN THE 20 TO 30 PERCENT RANGE AS
CAPPING SHOULD MINIMIZE COVERAGE. THE UPPER SHORTWAVE OVER CANADA
MOVES BY TUESDAY AND SHOULD HELP PUSH ANOTHER WEAK FRONTAL
BOUNDARY INTO THE NORTHERN CWA.
TUESDAY NIGHT-SATURDAY...
THE BROAD UPPER RIDGE INITIALLY CENTERED NEAR THE OHIO VALLEY WILL
GRADUALLY SHIFT WESTWARD AND WEAKEN WITH TIME. AS A RESULT...ZONAL
FLOW ALOFT WILL PERSIST FOR MUCH OF THE WEEK...TRANSITIONING TO
NORTHWEST FLOW TOWARDS NEXT WEEKEND. BOTH THE 12Z GFS/ECMWF
GENERALLY AGREE ON THE SYNOPTIC PATTERN EVOLUTION...WITH A SFC FRONT
SLOWLY SAGGING SOUTH THROUGH THE MIDDLE OF THE WEEK. KEPT
SLIGHT/CHANCE POPS TUE NIGHT-THUR NIGHT...GIVEN UNCERTAINTY IN THE
FRONTAL POSITION. THE GFS/ECMWF/GEM ALL INDICATE A STRONGER WAVE
DROPPING ACROSS SOUTHERN CANADA LATE THURSDAY...HELPING TO PUSH THE
FRONT AND BETTER PRECIP CHANCES SOUTHWARD. A SLOW COOLING TREND IS
ANTICIPATED...ALONG WITH LOWER HUMIDITY LEVELS. THE DEGREE OF WARMTH
FOR MID-WEEK WILL LIKELY DEPEND ON THE POSITION OF THE SFC
BOUNDARY...WITH CONTINUED VERY WARM TEMPS CLOSE TO 90 SOUTH OF THE
BOUNDARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 710 PM CDT SAT JUL 13 2013
QUESTION OVERNIGHT INTO SUNDAY MORNING IS LOW CLOUDS. BAND OF MVFR
CIGS REMAINS FROM RICHLAND COUNTY TO PARK RAPIDS. OTHERWISE LITTLE
CLOUD COVER IN CNTRL INTO NE ND INTO NW MN. MODEL MOS FORECASTS
SOME MVFR CIGS TO SPREAD OR DEVELOP NORTHWARD AS BOUNDARY MOVES
EAST AND WINDS ARE LIGHT AND ATMOSPHERE REMAINS MOIST. CONFIDENCE
IS QUITE LOW BUT MAINTAINED IDEA OF CIGS IN THE 1500 FT RANGE AT
MOST SITES 10Z-15Z PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1257 PM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 1257 PM CDT FRI JUL 12 2013
ADJUSTED TEMPS DOWN A BIT IN THE NORTHWESTERN COUNTIES FOR THIS
AFTERNOON AS PERSISTANT CLOUDS AND SHOWERS HAVE MADE HIGHS WELL
INTO THE 80S DOUBTFUL. MADE SOME ADDITIONAL TWEAKS TO CLOUDS AND
POPS. THINK THAT THE CAP WILL START TO BREAK LATER THIS AFTERNOON
AND STORMS SHOULD START TO FIRE BY EVENING.
UPDATE ISSUED AT 940 AM CDT FRI JUL 12 2013
BUMPED UP POPS IN OUR NORTHEASTERN COUNTIES AS THERE HAS BEEN SOME
CONVECTIVE DEVELOPMENT ALONG THE NOSE OF THE 850MB WARM AIR
ADVECTION. THINK THAT THIS WILL TRANSITION NORTHEASTWARD BY THIS
AFTERNOON AND THEN THE FOCUS OF CONVECTION WILL BE THE COLD FRONT
MOVING INTO THE CENTRAL CWA. ALSO BUMPED UP HIGHS A TAD IN OUR
SOUTHERN COUNTIES AS MANY GUIDANCE VALUES HAVE THAT AREA GETTING
INTO THE 90S. THE RAP AND HRRR HAVE THE SOUTH CLIMBING INTO THE
100S THIS AFTERNOON BUT THAT SEEMS EXTREME GIVEN THE HIGH DEW
POINTS IN THE AREA.
UPDATE ISSUED AT 713 AM CDT FRI JUL 12 2013
AT 12Z... A QUASI STATIONARY FRONTAL SYSTEM STRETCHED FROM A LOW
PRESSURE CENTER IN WESTERN SD... THROUGH CENTRAL ND AND UP INTO A
LOW PRESSURE CENTER IN NRN MAN. WAVES OF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WERE PROPAGATING NORTHEASTWARD AHEAD OF
THIS FRONT... WITH ONE AREA PUSHING OUT OF THE NRN RED RIVER
VALLEY AS A SECOND AREA WAS MOVING THROUGH THE BISMARCK AREA AND
ARCING TOWARDS TEH DEVILS LAKE BASIN.
THESE SHOWERS LOOK TO PERSIST INTO THE THE LATE FORENOON... UNTIL
LOW LEVEL JET STRENGTH DIMINISHES. 06Z NAM40 GUIDANCE SUGGESTS
THAT BLAYER WARMING THROUGH THE FORENOON AND EARLY AFTERNOON
/AHEAD OF THE FRONT/ SHOULD PRODUCE MIXED LAYER CAPE VALUES OF
2000 J/KG OR GREATER BY 21Z... WHILE COOLING H7 TEMPS SHOULD ALLOW
FOR ONSET OF DEEP CONVECTION AS PER PREVIOUS DISCUSSION.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI JUL 12 2013
FORECAST CHALLENGE WILL BE THE EXTENT AND DURATION OF SHOWERS AND
THUNDERSTORMS THROUGH THIS MORNING... THEN TIMING OF REDEVELOPMENT
LATER TODAY AND TONIGHT.
FOR NOW... LOW LEVEL MOISTURE TRANSPORT APPEARS TO HAVE SURGED IN
THE LAST COUPLE OF HOURS LEADING TO INCREASED DEEP CONVECTION ACROSS
NCNTRL AND FAR NERN ND... AHEAD OF A WEAK SFC COLD FRONT. THIS
AREA SHOWS 1500-2000 J/KG OF CAPE AND PWATS IN EXCESS OF 1.5
INCHES AT 08Z ANALYSIS... WITH 40KM RAP AND NAM GUIDANCE LIFTING
THIS AREA THROUGH FAR NERN ND INTO SRN MAN THROHGH 15Z. EXPECT
SOME BREAK IN THE ACTIVITY THROUGH MIDDAY WITH SERN ND AND WCNTRL
MN LIKELY TO HEAT OUT QUICKLY AND REACH CONVECTIVE TEMPS BY
MIDAFTERNOON.
NAM DEPICTION SEEMS REASONABLE THROUGH TODAY AND INTO THE EARLY
PORTION OF THE WEEKEND... SHOWING THE SFC FRONT SLOWLY SAGGING
INTO THE SOUTHERN FA BY TONIGHT AND STALLING THERE THROUGH SUNDAY
MORNING. LATE THIS AFTERNOON INTO EARLY SATURDAY MORNING EXPECT
THE FOCUS FOR DEEP CONVECTION TO SHIFT ACROSS THE SOUTHERN FA...
WITH PERIODS OF STRONG TO SEVERE THUNDERSTORMS POSSIBLE ALONG WITH
BRIEF HEAVY RAINS. CONVECTIVE INHIBITION SHUD BREAK DOWN FAIRLY
QUICKLY THROUGH MID AFTERNOON AS COOLER H7 TEMPS MOVE OVHD... WITH
SOME THREAT FOR ISOLD TORNADIC SUPERCELLS TO DEVELOP IN THE LATE
AFTERNOON...THROUGH CENTRAL PORTIONS OF THE RRV.
OVERNIGHT TONIGHT THROUGH SATURDAY... FOCUS WILL SWITCH TO HEAVIER
RAIN PRODUCING CONVECTIVE CLUSTERS ACROSS THE SOUTHERN HALF OF THE
THE RRV.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
SATURDAY NIGHT THROUGH SUNDAY... SOME BREAK IN THE THUNDERSTORM
ACTIVITY IS EXPECTED TO DEVELOP FROM NORTHWEST TO SOUTHEAST ON
SATURDAY. DEEP MOIST AND UNSTABLE FLOW SHUD RETURN TO TEH AREA ON
SUNDAY.
MONDAY THROUGH THURSDAY... LONG WAVE UPPER LEVEL RIDGE REMAINS
PARKED OVER CO THIS PERIOD. LONG WAVE TROUGH OVER WESTERN CANADA
SWEEPS INTO EASTERN CANADA BY THE END OF THE PERIOD. FLOW ALOFT
BECOMES NORTHWEST ALOFT OVER CANADA AND THE FAR NORTHERN PLAINS. A
FRONTAL BOUNDARY MOVES INTO THE AREA TUE OR WED. WILL BLEND THE
ECMWF AND GFS.
NORTHWEST FLOW ALOFT BECOMES ESTABLISHED OVER CANADA AND THE
NORTHERN STATES THIS PERIOD. GFS AND ECMWF WERE VACILLATING OVER
SOUTHERN CANADA AND FAR NORTHERN ZONES TUE. SO WILL REMOVE
PRECIPITATION FROM TUE AND TRIM BACK TUE NIGHT PRECIP FARTHER NORTH.
WILL KEEP YESTERDAYS POPS FOR WED NIGHT.
HIGH TEMPS INCREASED COUPLE DEGREES IN THE NORTHWEST ZONES TUE FROM
YESTERDAYS RUN. BOTH HIGH AND LOW TEMPS DECREASED ABOUT A DEGREE OR
TWO FOR WED AND THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1257 PM CDT FRI JUL 12 2013
RELATIVELY NARROW BAND SHRA/TSRA JUST ALONG AND BEHIND FRONTAL
BOUNDARY DRIFTING SLOWLY EAST ACROSS CWFA. BOUNDARY FORECAST ALONG A
BDE...TVF...JMS LINE BY 00Z THEN TO NJI...DTL...FR LINE BY 06Z. AS
IS TYPICAL WITH CONVECTION TIMING IS DIFFICULT AS IS THE WINDS IN
AND AROUND THE SHRA. HAVE TIMES PCPN AND WIND VARIATIONS BASED ON
OBS AND FORECAST MOVEMENT OF FRONT.
WINDS WILL GUST AT FAR...TVF AND BJI INTO THE AFTERNOON AS GRADIENT
SLOW TO RELAX. MVFR VSBY PSBL WITH SHRA OTRW VFR CONDS FORECAST
OUTSIDE BAND OF CONVECTION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GUST
LONG TERM...HOPPES
AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
940 AM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 940 AM CDT FRI JUL 12 2013
BUMPED UP POPS IN OUR NORTHEASTERN COUNTIES AS THERE HAS BEEN SOME
CONVECTIVE DEVELOPMENT ALONG THE NOSE OF THE 850MB WARM AIR
ADVECTION. THINK THAT THIS WILL TRANSITION NORTHEASTWARD BY THIS
AFTERNOON AND THEN THE FOCUS OF CONVECTION WILL BE THE COLD FRONT
MOVING INTO THE CENTRAL CWA. ALSO BUMPED UP HIGHS A TAD IN OUR
SOUTHERN COUNTIES AS MANY GUIDANCE VALUES HAVE THAT AREA GETTING
INTO THE 90S. THE RAP AND HRRR HAVE THE SOUTH CLIMBING INTO THE
100S THIS AFTERNOON BUT THAT SEEMS EXTREME GIVEN THE HIGH DEW
POINTS IN THE AREA.
UPDATE ISSUED AT 713 AM CDT FRI JUL 12 2013
AT 12Z... A QUASI STATIONARY FRONTAL SYSTEM STRETCHED FROM A LOW
PRESSURE CENTER IN WESTERN SD... THROUGH CENTRAL ND AND UP INTO A
LOW PRESSURE CENTER IN NRN MAN. WAVES OF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WERE PROPAGATING NORTHEASTWARD AHEAD OF
THIS FRONT... WITH ONE AREA PUSHING OUT OF THE NRN RED RIVER
VALLEY AS A SECOND AREA WAS MOVING THROUGH THE BISMARCK AREA AND
ARCING TOWARDS TEH DEVILS LAKE BASIN.
THESE SHOWERS LOOK TO PERSIST INTO THE THE LATE FORENOON... UNTIL
LOW LEVEL JET STRENGTH DIMINISHES. 06Z NAM40 GUIDANCE SUGGESTS
THAT BLAYER WARMING THROUGH THE FORENOON AND EARLY AFTERNOON
/AHEAD OF THE FRONT/ SHOULD PRODUCE MIXED LAYER CAPE VALUES OF
2000 J/KG OR GREATER BY 21Z... WHILE COOLING H7 TEMPS SHOULD ALLOW
FOR ONSET OF DEEP CONVECTION AS PER PREVIOUS DISCUSSION.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI JUL 12 2013
FORECAST CHALLENGE WILL BE THE EXTENT AND DURATION OF SHOWERS AND
THUNDERSTORMS THROUGH THIS MORNING... THEN TIMING OF REDEVELOPMENT
LATER TODAY AND TONIGHT.
FOR NOW... LOW LEVEL MOISTURE TRANSPORT APPEARS TO HAVE SURGED IN
THE LAST COUPLE OF HOURS LEADING TO INCREASED DEEP CONVECTION ACROSS
NCNTRL AND FAR NERN ND... AHEAD OF A WEAK SFC COLD FRONT. THIS
AREA SHOWS 1500-2000 J/KG OF CAPE AND PWATS IN EXCESS OF 1.5
INCHES AT 08Z ANALYSIS... WITH 40KM RAP AND NAM GUIDANCE LIFTING
THIS AREA THROUGH FAR NERN ND INTO SRN MAN THROHGH 15Z. EXPECT
SOME BREAK IN THE ACTIVITY THROUGH MIDDAY WITH SERN ND AND WCNTRL
MN LIKELY TO HEAT OUT QUICKLY AND REACH CONVECTIVE TEMPS BY
MIDAFTERNOON.
NAM DEPICTION SEEMS REASONABLE THROUGH TODAY AND INTO THE EARLY
PORTION OF THE WEEKEND... SHOWING THE SFC FRONT SLOWLY SAGGING
INTO THE SOUTHERN FA BY TONIGHT AND STALLING THERE THROUGH SUNDAY
MORNING. LATE THIS AFTERNOON INTO EARLY SATURDAY MORNING EXPECT
THE FOCUS FOR DEEP CONVECTION TO SHIFT ACROSS THE SOUTHERN FA...
WITH PERIODS OF STRONG TO SEVERE THUNDERSTORMS POSSIBLE ALONG WITH
BRIEF HEAVY RAINS. CONVECTIVE INHIBITION SHUD BREAK DOWN FAIRLY
QUICKLY THROUGH MID AFTERNOON AS COOLER H7 TEMPS MOVE OVHD... WITH
SOME THREAT FOR ISOLD TORNADIC SUPERCELLS TO DEVELOP IN THE LATE
AFTERNOON...THROUGH CENTRAL PORTIONS OF THE RRV.
OVERNIGHT TONIGHT THROUGH SATURDAY... FOCUS WILL SWITCH TO HEAVIER
RAIN PRODUCING CONVECTIVE CLUSTERS ACROSS THE SOUTHERN HALF OF THE
THE RRV.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
SATURDAY NIGHT THROUGH SUNDAY... SOME BREAK IN THE THUNDERSTORM
ACTIVITY IS EXPECTED TO DEVELOP FROM NORTHWEST TO SOUTHEAST ON
SATURDAY. DEEP MOIST AND UNSTABLE FLOW SHUD RETURN TO TEH AREA ON
SUNDAY.
MONDAY THROUGH THURSDAY... LONG WAVE UPPER LEVEL RIDGE REMAINS
PARKED OVER CO THIS PERIOD. LONG WAVE TROUGH OVER WESTERN CANADA
SWEEPS INTO EASTERN CANADA BY THE END OF THE PERIOD. FLOW ALOFT
BECOMES NORTHWEST ALOFT OVER CANADA AND THE FAR NORTHERN PLAINS. A
FRONTAL BOUNDARY MOVES INTO THE AREA TUE OR WED. WILL BLEND THE
ECMWF AND GFS.
NORTHWEST FLOW ALOFT BECOMES ESTABLISHED OVER CANADA AND THE
NORTHERN STATES THIS PERIOD. GFS AND ECMWF WERE VACILLATING OVER
SOUTHERN CANADA AND FAR NORTHERN ZONES TUE. SO WILL REMOVE
PRECIPITATION FROM TUE AND TRIM BACK TUE NIGHT PRECIP FARTHER NORTH.
WILL KEEP YESTERDAYS POPS FOR WED NIGHT.
HIGH TEMPS INCREASED COUPLE DEGREES IN THE NORTHWEST ZONES TUE FROM
YESTERDAYS RUN. BOTH HIGH AND LOW TEMPS DECREASED ABOUT A DEGREE OR
TWO FOR WED AND THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM CDT FRI JUL 12 2013
EXPECT MAINLY VFR CIGS AND VSBYS THROUGH THIS MORNING ACROSS THE FA...
WITH SCT SHOWERS AND AN ISOLD TSTM ALONG AND NEAR A BIS-DVL-ROX
LINE. BY MID AFTERNOON EXPECT SCT STRONG TO SEVERE TSMS TO DEVELOP
JUST EASTWARD OF THIS LINE... AND TO PROGRESS STEADILY EASTWARD
THROUGH EARLY EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GUST
LONG TERM...HOPPES
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
717 AM CDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 713 AM CDT FRI JUL 12 2013
AT 12Z... A QUASI STATIONARY FRONTAL SYSTEM STRETCHED FROM A LOW
PRESSURE CENTER IN WESTERN SD... THROUGH CENTRAL ND AND UP INTO A
LOW PRESSURE CENTER IN NRN MAN. WAVES OF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WERE PROPAGATING NORTHEASTWARD AHEAD OF
THIS FRONT... WITH ONE AREA PUSHING OUT OF THE NRN RED RIVER
VALLEY AS A SECOND AREA WAS MOVING THROUGH THE BISMARCK AREA AND
ARCING TOWARDS TEH DEVILS LAKE BASIN.
THESE SHOWERS LOOK TO PERSIST INTO THE THE LATE FORENOON... UNTIL
LOW LEVEL JET STRENGTH DIMINISHES. 06Z NAM40 GUIDANCE SUGGESTS
THAT BLAYER WARMING THROUGH THE FORENOON AND EARLY AFTERNOON
/AHEAD OF THE FRONT/ SHOULD PRODUCE MIXED LAYER CAPE VALUES OF
2000 J/KG OR GREATER BY 21Z... WHILE COOLING H7 TEMPS SHOULD ALLOW
FOR ONSET OF DEEP CONVECTION AS PER PREVIOUS DISCUSSION.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI JUL 12 2013
FORECAST CHALLENGE WILL BE THE EXTENT AND DURATION OF SHOWERS AND
THUNDERSTORMS THROUGH THIS MORNING... THEN TIMING OF REDEVELOPMENT
LATER TODAY AND TONIGHT.
FOR NOW... LOW LEVEL MOISTURE TRANSPORT APPEARS TO HAVE SURGED IN
THE LAST COUPLE OF HOURS LEADING TO INCREASED DEEP CONVECTION ACROSS
NCNTRL AND FAR NERN ND... AHEAD OF A WEAK SFC COLD FRONT. THIS
AREA SHOWS 1500-2000 J/KG OF CAPE AND PWATS IN EXCESS OF 1.5
INCHES AT 08Z ANALYSIS... WITH 40KM RAP AND NAM GUIDANCE LIFTING
THIS AREA THROUGH FAR NERN ND INTO SRN MAN THROHGH 15Z. EXPECT
SOME BREAK IN THE ACTIVITY THROUGH MIDDAY WITH SERN ND AND WCNTRL
MN LIKELY TO HEAT OUT QUICKLY AND REACH CONVECTIVE TEMPS BY
MIDAFTERNOON.
NAM DEPICTION SEEMS REASONABLE THROUGH TODAY AND INTO THE EARLY
PORTION OF THE WEEKEND... SHOWING THE SFC FRONT SLOWLY SAGGING
INTO THE SOUTHERN FA BY TONIGHT AND STALLING THERE THROUGH SUNDAY
MORNING. LATE THIS AFTERNOON INTO EARLY SATURDAY MORNING EXPECT
THE FOCUS FOR DEEP CONVECTION TO SHIFT ACROSS THE SOUTHERN FA...
WITH PERIODS OF STRONG TO SEVERE THUNDERSTORMS POSSIBLE ALONG WITH
BRIEF HEAVY RAINS. CONVECTIVE INHIBITION SHUD BREAK DOWN FAIRLY
QUICKLY THROUGH MID AFTERNOON AS COOLER H7 TEMPS MOVE OVHD... WITH
SOME THREAT FOR ISOLD TORNADIC SUPERCELLS TO DEVELOP IN THE LATE
AFTERNOON...THROUGH CENTRAL PORTIONS OF THE RRV.
OVERNIGHT TONIGHT THROUGH SATURDAY... FOCUS WILL SWITCH TO HEAVIER
RAIN PRODUCING CONVECTIVE CLUSTERS ACROSS THE SOUTHERN HALF OF THE
THE RRV.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
SATURDAY NIGHT THROUGH SUNDAY... SOME BREAK IN THE THUNDERSTORM
ACTIVITY IS EXPECTED TO DEVELOP FROM NORTHWEST TO SOUTHEAST ON
SATURDAY. DEEP MOIST AND UNSTABLE FLOW SHUD RETURN TO TEH AREA ON
SUNDAY.
MONDAY THROUGH THURSDAY... LONG WAVE UPPER LEVEL RIDGE REMAINS
PARKED OVER CO THIS PERIOD. LONG WAVE TROUGH OVER WESTERN CANADA
SWEEPS INTO EASTERN CANADA BY THE END OF THE PERIOD. FLOW ALOFT
BECOMES NORTHWEST ALOFT OVER CANADA AND THE FAR NORTHERN PLAINS. A
FRONTAL BOUNDARY MOVES INTO THE AREA TUE OR WED. WILL BLEND THE
ECMWF AND GFS.
NORTHWEST FLOW ALOFT BECOMES ESTABLISHED OVER CANADA AND THE
NORTHERN STATES THIS PERIOD. GFS AND ECMWF WERE VACILLATING OVER
SOUTHERN CANADA AND FAR NORTHERN ZONES TUE. SO WILL REMOVE
PRECIPITATION FROM TUE AND TRIM BACK TUE NIGHT PRECIP FARTHER NORTH.
WILL KEEP YESTERDAYS POPS FOR WED NIGHT.
HIGH TEMPS INCREASED COUPLE DEGREES IN THE NORTHWEST ZONES TUE FROM
YESTERDAYS RUN. BOTH HIGH AND LOW TEMPS DECREASED ABOUT A DEGREE OR
TWO FOR WED AND THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM CDT FRI JUL 12 2013
EXPECT MAINLY VFR CIGS AND VSBYS THROUGH THIS MORNING ACROSS THE FA...
WITH SCT SHOWERS AND AN ISOLD TSTM ALONG AND NEAR A BIS-DVL-ROX
LINE. BY MID AFTERNOON EXPECT SCT STRONG TO SEVERE TSMS TO DEVELOP
JUST EASTWARD OF THIS LINE... AND TO PROGRESS STEADILY EASTWARD
THROUGH EARLY EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GUST
SHORT TERM...GUST
LONG TERM...HOPPES
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
410 AM CDT FRI JUL 12 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI JUL 12 2013
FORECAST CHALLENGE WILL BE THE EXTENT AND DURATION OF SHOWERS AND
THUNDERSTORMS THROUGH THIS MORNING... THEN TIMING OF REDEVELOPMENT
LATER TODAY AND TONIGHT.
FOR NOW... LOW LEVEL MOISTURE TRANSPORT APPEARS TO HAVE SURGED IN
THE LAST COUPLE OF HOURS LEADING TO INCREASED DEEP CONVECTION ACROSS
NCNTRL AND FAR NERN ND... AHEAD OF A WEAK SFC COLD FRONT. THIS
AREA SHOWS 1500-2000 J/KG OF CAPE AND PWATS IN EXCESS OF 1.5
INCHES AT 08Z ANALYSIS... WITH 40KM RAP AND NAM GUIDANCE LIFTING
THIS AREA THROUGH FAR NERN ND INTO SRN MAN THROHGH 15Z. EXPECT
SOME BREAK IN THE ACTIVITY THROUGH MIDDAY WITH SERN ND AND WCNTRL
MN LIKELY TO HEAT OUT QUICKLY AND REACH CONVECTIVE TEMPS BY
MIDAFTERNOON.
NAM DEPICTION SEEMS REASONABLE THROUGH TODAY AND INTO THE EARLY
PORTION OF THE WEEKEND... SHOWING THE SFC FRONT SLOWLY SAGGING
INTO THE SOUTHERN FA BY TONIGHT AND STALLING THERE THROUGH SUNDAY
MORNING. LATE THIS AFTERNOON INTO EARLY SATURDAY MORNING EXPECT
THE FOCUS FOR DEEP CONVECTION TO SHIFT ACROSS THE SOUTHERN FA...
WITH PERIODS OF STRONG TO SEVERE THUNDERSTORMS POSSIBLE ALONG WITH
BRIEF HEAVY RAINS. CONVECTIVE INHIBITION SHUD BREAK DOWN FAIRLY
QUICKLY THROUGH MID AFTERNOON AS COOLER H7 TEMPS MOVE OVHD... WITH
SOME THREAT FOR ISOLD TORNADIC SUPERCELLS TO DEVELOP IN THE LATE
AFTERNOON...THROUGH CENTRAL PORTIONS OF THE RRV.
OVERNIGHT TONIGHT THROUGH SATURDAY... FOCUS WILL SWITCH TO HEAVIER
RAIN PRODUCING CONVECTIVE CLUSTERS ACROSS THE SOUTHERN HALF OF THE
THE RRV.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
SATURDAY NIGHT THROUGH SUNDAY... SOME BREAK IN THE THUNDERSTORM
ACTIVITY IS EXPECTED TO DEVELOP FROM NORTHWEST TO SOUTHEAST ON
SATURDAY. DEEP MOIST AND UNSTABLE FLOW SHUD RETURN TO TEH AREA ON
SUNDAY.
MONDAY THROUGH THURSDAY... LONG WAVE UPPER LEVEL RIDGE REMAINS
PARKED OVER CO THIS PERIOD. LONG WAVE TROUGH OVER WESTERN CANADA
SWEEPS INTO EASTERN CANADA BY THE END OF THE PERIOD. FLOW ALOFT
BECOMES NORTHWEST ALOFT OVER CANADA AND THE FAR NORTHERN PLAINS. A
FRONTAL BOUNDARY MOVES INTO THE AREA TUE OR WED. WILL BLEND THE
ECMWF AND GFS.
NORTHWEST FLOW ALOFT BECOMES ESTABLISHED OVER CANADA AND THE
NORTHERN STATES THIS PERIOD. GFS AND ECMWF WERE VACILLATING OVER
SOUTHERN CANADA AND FAR NORTHERN ZONES TUE. SO WILL REMOVE
PRECIPITATION FROM TUE AND TRIM BACK TUE NIGHT PRECIP FARTHER NORTH.
WILL KEEP YESTERDAYS POPS FOR WED NIGHT.
HIGH TEMPS INCREASED COUPLE DEGREES IN THE NORTHWEST ZONES TUE FROM
YESTERDAYS RUN. BOTH HIGH AND LOW TEMPS DECREASED ABOUT A DEGREE OR
TWO FOR WED AND THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1115 PM CDT THU JUL 11 2013
THE CHANCES FOR SHOWERS AND STORMS WILL INCREASE FROM WEST TO EAST
THROUGH TOMORROW. EXPECT MAINLY VFR CONDITIONS THOUGH WITH HIGH
CLOUD BASES WITH WARM AIR ALOFT. THERE COULD BE SOME POCKETS OF
MVFR CONDITIONS NEAR STRONGER STORMS AND DOWNPOURS...BUT WILL NOT
MENTION AT THIS POINT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GUST
LONG TERM...HOPPES
AVIATION...DK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
929 PM CDT SAT JUL 13 2013
.UPDATE...
WITH ONLY WEAK TO STRONG STORMS ACROSS NORTHWEST SD AND NO
INTENSIFICATION EXPECTED WENT AHEAD AND CANCELLED THE SEVERE
THUNDERSTORM WATCH. WIND GUSTS TO 45 MPH AROUND STRONG STORMS ARE
STILL POSSIBLE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH TUESDAY MORNING
VERY MOIST...UNSTABLE ATMOSPHERE OVER THE REGION THIS AFTERNOON.
WIDESPREAD CUMULUS FIELD EXTENDS FROM FARGO DOWN TO
ABERDEEN...PIERRE...AND CONTINUES WEST INTO WESTERN SD. IN EASTERN
SD...CAPE VALUES ARE PUSHING 2500 J/KG WHILE FARTHER WEST WE ARE
SEEING BETTER SHEAR...SO THE STORM ENVIRONMENT VARIES QUITE A BIT
FROM ONE END OF THE STATE TO THE OTHER. WE ARE LACKING FORCING
ALOFT AS THE FLOW AT 500HPA IS GENERALLY SOUTHWESTERLY AND ZONAL.
H7 TEMPERATURES RANGE BETWEEN +10 AND +13C...THOUGH WE ARE ALREADY
SEEING SOME WEAK VERTICAL DEVELOPMENT IN THE CUMULUS OVERHEAD. NOT
A SURPRISE AS 3PM READING IS 88F WITH A DEWPOINT OF 74F.
THUS...WILL GO WITH DECENT POPS LATE THIS AFTERNOON.
OVERNIGHT...LOW LEVEL JET WILL SET UP MAINLY SOUTH AND EAST OF THE
CWA...THOUGH CONVERGENCE IS MAXIMIZED ACROSS SOUTHEAST COUNTIES.
WITH +2 TO +3 SDEV PWATS AND SLOW STORM MOTION...WILL CONTINUE
MENTION OF HEAVY RAIN. THE JET WEAKENS AND CURVES MORE EAST BY
MORNING...PUSHING CONVECTION WITH IT EAST AS WELL.
MONSOON MOISTURE IN THE MID LEVELS WILL CONTINUE TO PULL IN FROM
THE SOUTHWEST FOR SUNDAY...SO DESPITE PUSH OF DRIER AIR THAT
BEGINS TO MOVE IN FROM THE SOUTHEAST...WILL CONTINUE MENTION OF
THUNDERSTORMS. MONSOON MOISTURE WILL BE CUT OFF BY EARLY MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY
LONG RANGE MODELS REMAIN IN FAIRLY CONSISTENT AGREEMENT WITH
UPPER PATTERN THROUGH NEXT WEEK. 500HPA HIGH PRESSURE SYSTEM
RETRO- GRADES TO THE WEST THROUGH THE MIDDLE OF THE
WEEK...BASICALLY CUTTING OFF ANY RETURN MOISTURE OUT OF THE GULF.
500HPA HEIGHTS CLIMB SLIGHTLY THROUGH THE END OF THE WEEK...SO
TEMPS SHOULD BE NEAR NORMAL TO PERHAPS SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR.
BY THURSDAY...UPPER FLOW BEGINS TO BUCKLE SLIGHTLY...WITH A MORE
NW FLOW SETTING UP OVER CWA...AND MODELS BEGINNING TO SHOW MORE
S/W ACTIVITY TRANSLATING OVER THE AREA. ABILITY TO DEFINE ANY
SINGLE 700HPA OR 500HPA WAVE AS THE MAIN PCPN PRODUCER DIFFICULT
AT BEST AT THIS TIME. CONTINUED ALL BLEND THINKING OF SLIGHT
CHC/LOW CHC POPS AT THE END OF THE WEEK.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 10Z. AS A FRONT SLIDES
THROUGH THE DAKOTAS THUNDERSTORMS WILL LIKELY IMPACT KMBG. USED
THE HRRR TO TIME VCTS WITH A START AROUND 4Z. STORMS MAY ALSO
AFFECT THE OTHER TAF SITES BUT TIMING IS STILL TOO DIFFICULT TO
DETERMINE.
WITH ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS...LOOK FOR SCT
MVFR VSBYS/CIGS DUE TO FOG ACROSS THE KABR AND KATY TERMINALS AFTER
10Z SUNDAY. MVFR CONDITIONS MAY STICK AROUND AND AFFECT
KABR/KATY/KMBG THROUGH MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...CONNELLY
LONG TERM...HINTZ
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
647 PM CDT SAT JUL 13 2013
.UPDATE...
ADJUSTED OVERNIGHT POPS QUITE A BIT BASED ON LATEST HRRR AND
ONGOING CONVECTION ACROSS WESTERN SOUTH DAKOTA. EXPECT STORMS TO
TRACK EAST THROUGH THE NIGHT WITH PERHAPS FURTHER DEVELOPMENT WITH
AN ADDITIONAL SHORTWAVE AFTER MIDNIGHT.
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH TUESDAY MORNING
VERY MOIST...UNSTABLE ATMOSPHERE OVER THE REGION THIS AFTERNOON.
WIDESPREAD CUMULUS FIELD EXTENDS FROM FARGO DOWN TO
ABERDEEN...PIERRE...AND CONTINUES WEST INTO WESTERN SD. IN EASTERN
SD...CAPE VALUES ARE PUSHING 2500 J/KG WHILE FARTHER WEST WE ARE
SEEING BETTER SHEAR...SO THE STORM ENVIRONMENT VARIES QUITE A BIT
FROM ONE END OF THE STATE TO THE OTHER. WE ARE LACKING FORCING
ALOFT AS THE FLOW AT 500HPA IS GENERALLY SOUTHWESTERLY AND ZONAL.
H7 TEMPERATURES RANGE BETWEEN +10 AND +13C...THOUGH WE ARE ALREADY
SEEING SOME WEAK VERTICAL DEVELOPMENT IN THE CUMULUS OVERHEAD. NOT
A SURPRISE AS 3PM READING IS 88F WITH A DEWPOINT OF 74F.
THUS...WILL GO WITH DECENT POPS LATE THIS AFTERNOON.
OVERNIGHT...LOW LEVEL JET WILL SET UP MAINLY SOUTH AND EAST OF THE
CWA...THOUGH CONVERGENCE IS MAXIMIZED ACROSS SOUTHEAST COUNTIES.
WITH +2 TO +3 SDEV PWATS AND SLOW STORM MOTION...WILL CONTINUE
MENTION OF HEAVY RAIN. THE JET WEAKENS AND CURVES MORE EAST BY
MORNING...PUSHING CONVECTION WITH IT EAST AS WELL.
MONSOON MOISTURE IN THE MID LEVELS WILL CONTINUE TO PULL IN FROM
THE SOUTHWEST FOR SUNDAY...SO DESPITE PUSH OF DRIER AIR THAT
BEGINS TO MOVE IN FROM THE SOUTHEAST...WILL CONTINUE MENTION OF
THUNDERSTORMS. MONSOON MOISTURE WILL BE CUT OFF BY EARLY MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY
LONG RANGE MODELS REMAIN IN FAIRLY CONSISTENT AGREEMENT WITH
UPPER PATTERN THROUGH NEXT WEEK. 500HPA HIGH PRESSURE SYSTEM
RETRO- GRADES TO THE WEST THROUGH THE MIDDLE OF THE
WEEK...BASICALLY CUTTING OFF ANY RETURN MOISTURE OUT OF THE GULF.
500HPA HEIGHTS CLIMB SLIGHTLY THROUGH THE END OF THE WEEK...SO
TEMPS SHOULD BE NEAR NORMAL TO PERHAPS SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR.
BY THURSDAY...UPPER FLOW BEGINS TO BUCKLE SLIGHTLY...WITH A MORE
NW FLOW SETTING UP OVER CWA...AND MODELS BEGINNING TO SHOW MORE
S/W ACTIVITY TRANSLATING OVER THE AREA. ABILITY TO DEFINE ANY
SINGLE 700HPA OR 500HPA WAVE AS THE MAIN PCPN PRODUCER DIFFICULT
AT BEST AT THIS TIME. CONTINUED ALL BLEND THINKING OF SLIGHT
CHC/LOW CHC POPS AT THE END OF THE WEEK.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 10Z. AS A FRONT SLIDES
THROUGH THE DAKOTAS THUNDERSTORMS WILL LIKELY IMPACT KMBG. USED
THE HRRR TO TIME VCTS WITH A START AROUND 4Z. STORMS MAY ALSO
AFFECT THE OTHER TAF SITES BUT TIMING IS STILL TOO DIFFICULT TO
DETERMINE.
WITH ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS...LOOK FOR SCT
MVFR VSBYS/CIGS DUE TO FOG ACROSS THE KABR AND KATY TERMINALS AFTER
10Z SUNDAY. MVFR CONDITIONS MAY STICK AROUND AND AFFECT
KABR/KATY/KMBG THROUGH MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...CONNELLY
LONG TERM...HINTZ
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1030 AM EDT FRI JUL 12 2013
.DISCUSSION...
A CLOSED MID/UPPER LEVEL LOW OVER WV IS DRIFTING SOUTHWARD TODAY.
THIS WILL PRODUCE COOLER MIDLEVEL TEMPS AND STEEPER LAPSE RATES
OVER NORTHERN PORTIONS OF THE AREA THIS AFTERNOON. RUC SHOWS
CONVECTIVE INHIBITION IS WEAKEST NORTH...WITH A WEAK INVERSION
REMAINING AT TYS AND CHA. SO THE CURRENT POP FORECAST OF SLIGHT/LOW
CHANCES NORTH AND ALONG THE MOUNTAINS LOOKS ON TRACK. WITH WETB
BULB ZERO HEIGHTS FALLING TO AROUND 10 KFT NORTH...SOME SMALL HAIL
MAY BE POSSIBLE...BUT MEETING SEVERE CRITERIA SEEMS UNLIKELY. TEMPS
APPEAR ON TRACK AS WELL...SO NO UPDATE WILL BE NEEDED.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1145 PM CDT THU JUL 11 2013
.AVIATION...
VFR CONDITIONS PREVAILING FOR THE NEXT 24 HOURS AS UPPER LEVEL
HIGH PRESSURE CENTERED OVER THE SRN ROCKIES KEEPS S TX UNDER
GENERAL SUBSIDENCE. OTHERWISE S-SELY SFC WINDS AT 5-10 KNOTS
PREVAILING.
&&
.PREV DISCUSSION... /ISSUED 1000 PM CDT THU JUL 11 2013/
UPDATE...
MOST SHOWERS AND THUNDERSTORMS OVER EASTERN AND CENTRAL TEXAS HAVE
COME TO AN END THIS EVENING WITH ONLY SOME LINGERING SHOWERS TO
THE NORTH OF THE HILL COUNTRY. THE ONLY THING LEFT FROM THESE
EARLIER STORMS IS AN OUTFLOW BOUNDARY ENTERING THE NORTHEAST PART
OF WILLIAMSON COUNTY. THIS BOUNDARY WILL BRING A SLIGHTLY WIND
SHIFT ACROSS PARTS OF THE NORTHEAST HILL COUNTRY FOR A SHORT
PERIOD OF TIME WITH WIND GUSTS UP TO 20 MPH. CURRENT FORECAST IS ON
TRACK FOR THE REST OF THIS EVENING INTO FRIDAY MORNING.
PREV DISCUSSION... /ISSUED 707 PM CDT THU JUL 11 2013/
UPDATE...
INCREASED CLOUD COVERAGE THIS EVENING INTO THE OVERNIGHT HOURS AS
MID TO UPPER MOISTURE ASSOCIATED WITH A GROUP OF STORMS OVER EAST
TEXAS MOVE TO THE SOUTHWEST. HI-RES MODELS AND LATEST RAP SOLUTION
SHOWS STORMS SCATTERING OUT BEFORE ARRIVING TO THE NORTHEAST PART OF
THE HILL COUNTRY. WILL MONITOR CLOSELY THESE STORMS AS THEY
APPROACH THE LOCAL AREA FOR THE NEXT FEW HOURS AND ADJUST WEATHER
GRIDS IF NECESSARY. UPDATED ZONES OUT SHORTLY.
PREV DISCUSSION... /ISSUED 623 PM CDT THU JUL 11 2013/
AVIATION...
VFR CONDITIONS PREVAILING FOR THE NEXT 24 HOURS AS UPPER LEVEL
HIGH PRESSURE CENTERED OVER THE SRN ROCKIES KEEPS S TX UNDER
GENERAL SUBSIDENCE. WEAK DISTURBANCES ROTATING AROUND THE UPPER
RIDGE WILL MAINLY AFFECT THE N TX AREA WITH ISOLD-SCT AFTERNOON
AND EVENING SHRA/TSRA THAT SHOULD REMAIN NORTH OF THE S CENTRAL
TX. OTHERWISE S-SELY SFC WINDS AT 5-10 KNOTS PREVAILING.
PREV DISCUSSION... /ISSUED 331 PM CDT THU JUL 11 2013/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
THE SUBTROPICAL RIDGE AXIS REMAINS THE DOMINANT WEATHER FEATURE
THROUGH THE SHORT TERM PORTION OF THE FORECAST. GIVEN THE INFLUENCE
FROM THIS RIDGE...WE EXPECT A CONTINUATION OF DRY WEATHER ACROSS
SOUTH CENTRAL TEXAS. THE SHORT RANGE MODELS DO SHOW SOME CONVECTION
CONTINUING ACROSS NORTH TEXAS THIS EVENING...WITH SOME ACTIVITY
DRIFTING INTO CENTRAL TEXAS LATE TONIGHT INTO EARLY FRIDAY
MORNING. WE HAVE LOW CONFIDENCE THIS CONVECTION WILL BE ABLE TO
MOVE INTO OUR REGION...SO WE WILL CONTINUE WITH A DRY FORECAST.
HIGH TEMPERATURES REMAIN ABOVE NORMAL ON FRIDAY AND WILL RANGE
FROM THE MID/UPPER 90S IN THE HILL COUNTRY...WITH UPPER 90S TO
100-103 FOR THE REMAINDER OF THE REGION. OVERNIGHT LOWS WILL
REMAIN IN THE 70S.
LONG TERM (SATURDAY THROUGH THURSDAY)...
A BROAD SUBTROPICAL RIDGE WILL ENCOMPASS MUCH OF THE CENTRAL CONUS
THROUGH THE FIRST HALF OF THE UPCOMING WEEKEND. DRY CONDITIONS AND
ABOVE NORMAL TEMPERATURES WILL CONTINUE FOR ALL AREAS ON SATURDAY.
BASED ON THE LATEST MODEL DATA...IT APPEARS SATURDAY WILL BE THE
WARMEST DAY OF THE FORECAST PERIOD...WITH HIGHS GENERALLY IN THE
UPPER 90S TO NEAR 104. MODEL DATA FROM THE LAST SEVERAL DAYS WERE
CONSISTENT IN SHOWING A TUTT LOW MOVE ACROSS THE REGION LATE THIS
WEEKEND INTO EARLY NEXT WEEK. THE LATEST GUIDANCE DOES CONTINUE TO
SHOW A WEAK TUTT LOW...BUT ALSO SHOW A LOW DEVELOPING OVER THE UPPER
MIDWEST BY LATE FRIDAY. THE MODELS THEN RETROGRADE THIS LOW
SOUTHWEST INTO THE SOUTHERN U.S. PLAINS BY EARLY NEXT WEEK.
OVERALL... WE ARE NOT TOO CONFIDENT IN RAIN CHANCES INTO EARLY NEXT
WEEK. FOR NOW... WE WILL MAINTAIN THE CURRENT FORECAST WHICH
GENERALLY CALLS FOR A SLIGHT CHANCE (20%) OF RAIN FOR MOST AREAS
SUNDAY NIGHT THROUGH TUESDAY NIGHT. THROUGH THE REMAINDER OF THE
FORECAST PERIOD...WE WILL GO WITH A DRY FORECAST...EXCEPT NEAR THE
COASTAL PLAINS WHERE AFTERNOON/EVENING SEA BREEZE CONVECTION REMAINS
POSSIBLE. AS MENTIONED ABOVE...TEMPERATURES WILL PEAK ON SATURDAY...
THEN VERY SLOWLY MODERATE SUNDAY THROUGH THURSDAY. IT APPEARS A
BREAK FROM TRIPLE DIGIT HIGHS IS IN STORE...BUT TEMPERATURES WILL
CONTINUE TO REMAIN ABOVE NORMAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 75 103 75 104 76 / - - - - -
AUSTIN BERGSTROM INTL AIRPORT 72 101 72 102 72 / - - - - -
NEW BRAUNFELS MUNI AIRPORT 71 100 72 101 72 / - - - - -
BURNET MUNI AIRPORT 74 101 76 101 74 / 10 - - - -
DEL RIO INTL AIRPORT 77 101 77 103 77 / - - - - -
GEORGETOWN MUNI AIRPORT 74 101 74 101 74 / 10 - - - -
HONDO MUNI AIRPORT 74 101 74 102 73 / - - - - -
SAN MARCOS MUNI AIRPORT 72 100 72 101 72 / - - - - -
LA GRANGE - FAYETTE REGIONAL 76 102 76 101 77 / - 10 10 10 10
SAN ANTONIO INTL AIRPORT 77 101 77 101 77 / - - - - -
STINSON MUNI AIRPORT 75 101 75 101 75 / - - - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
321 PM EDT FRI JUL 12 2013
.SYNOPSIS...
UPPER LOW PRESSURE OVER WEST VIRGINIA WILL DRIFT WEST
TONIGHT...THEN THEN SLOWLY DRIFT WEST INTO KENTUCKY AND TENNESSEE
DURING THE WEEKEND. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD
WESTWARD FROM THE WESTERN ATLANTIC INTO THE MID- ATLANTIC REGION
BY EARLY NEXT WEEK. SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WEEKEND...BUT SHOULD DIMINISH SOME NEXT WEEK AND
BECOME MORE ISOLATED AND TYPICAL OF SUMMER EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 320 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
WILL CONTINUE INTO TONIGHT. WITH PWAT STILL RELATIVELY HIGH...LOW
FFG(LESS THAN 1.0 INCH/HR IN SOME COUNTY) AND VERY WET
GROUND (RECENT RAINS)...THE POTENTIAL FOR FLASH FLOODING
CONTINUES THIS AFTERNOON INTO TONIGHT. HRRR AND RAP
FOCUS CONVECTION ON THE SOUTHERN BLUE RIDGE AND EASTWARD THIS
EVENING...THEN TAPER OFF OVERNIGHT INTO SATURDAY MORNING. GFS AND
NAM SEEM TO KEEP THE AXIS OF HEAVIER PRECIPITATION FURTHER EAST.
KEEP THE HIGHEST POPS THIS EVENING INTO TONIGHT...THEN DECREASE
POPS OVERNIGHT. EXPECTED SHOWERS TO LINGER INTO THE OVERNIGHT
HOURS WITH AREAS OF FOG. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE UPPER 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE SOUTHEAST.
ON SATURDAY...THE CLOSED MID/UPR LOW WILL BE OVER KY AND IS
PROGGED TO DRIFT W REACHING THE MISS RIVER VALLEY BY 00Z SUNDAY.
PLENTY OF MOISTURE AND WEAK MID LEVEL VORTICITY CENTERS MOVE
ACROSS THE REGION DURING THE AFTERNOON AND EVENING CREATING
SCATTERED SHOWERS AND THUNDERSTORMS. ADDITIONAL FLASH FLOOD
WATCHES MAY BE ISSUED THIS WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 300 PM EDT FRIDAY...
BY SUNDAY MORNING...MOST OF THE MEDIUM RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE UPPER LEVEL LOW WILL BE POSITIONED SOMEWHERE IN
THE MISSISSIPPI VALLEY WITH AN UPPER LEVEL HIGH BUILDING IN THE MID-
ATLANTIC REGION. WHILE THE DEEPEST MOISTURE WILL BE PULLED WEST OF
OUR FORECAST AREA...A WEAK SOUTHEAST LOW LEVEL FLOW AND WEAK WAVES
MOVING UNDER THE SOUTHERN PERIPHERY OF THE UPPER LEVEL HIGH WILL
BRING SCATTERED SHOWERS AND STORMS. PLACED THE HIGHEST POPS ALONG
THOSE FAVORED UPSLOPE EAST FACING SLOPES ALONG THE SOUTHERN BLUE
RIDGE.
DRIER AIR FINALLY ARRIVES SUNDAY NIGHT AND MONDAY AS PWATS FALL TO
UNDER 1.5 INCHES UNDER THE EXPANDING UPPER LEVEL RIDGE. WHILE
ISOLATED CONVECTION IS POSSIBLE IN THE MOUNTAINS...MOST AREAS WILL
BE DRY. WITH THE BUILDING RIDGE AND WARMING 850MB TEMPS...LEANED
TOWARD THE WARMER GFS GUIDANCE FOR FORECAST HIGHS.
CONTINUED VERY WARM TUESDAY...WITH SLIGHTLY INCREASED COVERAGE IN
SHOWERS AND STORMS IN THE MOUNTAINS AS PWATS INCREASE AND THE HINT
OF A WEAK UPPER LEVEL WAVE DRIFTS SOUTH UNDER THE UPPER RIDGE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
THE LONG RANGE DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD
AGREEMENT THAT AN LARGE UPPER RIDGE...AS STRONG AS 598DM...WILL OVER
OUR FORECAST AREA THROUGH THE LONG TERM PERIOD...WITH THE RIDGE
DAMPENING BY LATE IN THE WEEK AS A BROAD TROF FORMS IN EASTERN
CANADA.
TEMPERATURES WILL BE ABOVE NORMAL WITH GEFS ENSEMBLES SHOWING 850MB
TEMPS 1-2 STANDARD DEVIATIONS ABV AVERAGE AND 500MB HEIGHTS ALSO 1-2
SD ABOVE AVERAGE. INCREASED HIGHS A DEGREE OR TWO DURING THE LONG
TERM PERIOD. WHILE THE UPPER RIDGE WEAKENS LATE THE WEEK...A MORE
WESTERLY (DOWNSLOPING) COMPONENT TO THE WIND WILL KEEP TEMPS ABV
NORMAL.
EXPECT PRECIP TO BE DRIVEN BY DAYTIME HEATING...AND MAINLY CONFINED
TO THE MOUNTAINS. PWATS INCREASE FROM 1.5 TO GREATER THAN 2.0 INCHES
BY LATE IN THE WEEK...SO WHILE THE COVERAGE WILL BE WIDELY SCATTERED
SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
CLOSED UPPER LOW OVER THE AREA SCHEDULED TO RETROGRADE TO MIDWEST
OVER THE NEXT FEW DAYS. SCT-BKN MVFR CLOUDS WITH POCKETS OF IFR
IN CONVECTION AND AREAS OF FOG.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
EXPECTED THIS AFTERNOON INTO TONIGHT. BELIEVE THE TRENDS WILL BE
SIMILAR TO PREVIOUS DAYS IN A WEAKLY FORCED ENVIRONMENT. KLWB
HAS THE BEST CHANCE OF A THUNDERSTORM THIS AFTERNOON.
AS UPPER LOW BEGINS ITS WWD TREK...A SHORTWAVE WILL DRIFT OVER
THE AREA TONIGHT WITH FLOW BECOMING SELY. THIS SHOULD KEEP
SHOWERS IN THE AREA FOR THE OVERNIGHT. MODELS ALSO SHOW MOISTURE
SUCKING BACK WWD AS THE LOW MOVES...AND THIS SHOULD LEAD TO
IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT.
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
AS OF 120 PM EDT FRIDAY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
RIVER FLOOD WARNING IS CANCELLED FOR THE DAN RIVER NEAR DANVILLE.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN
VIRGINIA...DAN RIVER NEAR PACES...MINOR FLOODING IS FORECAST.
MINOR FLOODING IS ALSO OCCURING ALONG THE ROANOKE RIVER AT
RANDOLPH...DAN RIVER AT SOUTH BOSTON. REFER TO LATEST FLOOD
WARNINGS...RIVER FLOOD WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/MBS/RAB
HYDROLOGY...KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
133 PM EDT FRI JUL 12 2013
.SYNOPSIS...
LOW PRESSURE WILL DRIFT INTO WEST VIRGINIA AND STALL...THEN DRIFT
SLOWLY BACK WEST INTO THE TENNESSEE VALLEY THROUGH EARLY NEXT
WEEK. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD WESTWARD FROM THE
WESTERN ATLANTIC INTO THE MID-ATLANTIC REGION BY EARLY NEXT WEEK.
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE WEEKEND...BUT
SHOULD DIMINISH SOME NEXT WEEK AND BECOME MORE ISOLATED AND
TYPICAL OF SUMMER EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS OVER
THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1110 AM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
KFCX HAS BEEN REPAIRED AND IS BACK IN SERVICE.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
EXPECTED TO DEVELOP THIS AFTERNOON INTO TONIGHT. WITH PWAT STILL
RELATIVELY HIGH...LOW FFG AND VERY WET GROUND...THE POTENTIAL FOR
FLASH FLOODING CONTINUES. HRRR...AND RAP SEEM TO FOCUS ALONG
BLUE RIDGE AND EASTWARD THIS AFTERNOON INTO TONIGHT. UPPER LOW
PROGGED TO MOVE WESTWARD TODAY INTO WEEKEND. MADE SOME MINOR
ADJUSTMENTS IN POPS AND TEMPERATURES FOR THIS AFTERNOON.
MORE LATER....
AS OF 920 AM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
KFCX WILL BE DOWN THROUGH EARLY AFTERNOON FOR EMERGENCY REPAIRS.
PNS OUT WITH RAINFALL TOTALS.
THE 08AM/12Z RNK SOUNDING SHOWED PWATS ARE LOWER AT 1.09 INCHES
WITH NORTHERLY FLOW. INSTABILITY SHOULD BE LESS THIS AFTERNOON AS
MORE EASTERLY FLOW EVOLVES AROUND THE BUILDING ATLANTIC HIGH. BUT
WITH THE UPPER LOW...CONVECTION WITH POCKETS OF HEAVY RAIN WILL
DEVELOP THIS AFTERNOON INTO TONIGHT. THE THREAT FOR FLASH FLOODING
CONTINUES TODAY BECAUSE OF THE EXTREMELY LOW FFG VALUES...IN SOME
CASES LESS THAN 1.0 INCH/HR FOR FLASH FLOODING. ADJUSTED
TEMPERATURES AND DEWPOINTS FOR LATE MORNING INTO THIS AFTERNOON.
MODIFIED POPS INTO EARLY THIS AFTERNOON. WILL MAKE MORE
ADJUSTMENTS AS MORNING PROGRESSES.
AS OF 500 AM EDT FRIDAY...
FLASH FLOOD WATCH HAS BEEN EXTENDED UNTIL 8 AM SATURDAY MORNING.
EXCESSIVE RAINFALL IN PARTS OF THE FORECAST AREA THIS MORNING AS
UPPER LOW JUST TO OUR NORTHWEST COMBINED WITH VERY TROPICAL AIR
MASS ACROSS THE PIEDMONT CONTINUES. TRAINING AND BACKBUILDING
THUNDERSTORMS BROUGHT RECORD RAINFALL AMOUNTS TO DANVILLE
OVERNIGHT...WITH OVER FOUR INCHES OF RAIN AT THE DANVILLE AIRPORT
SINCE ABOUT 10 PM THURSDAY EVENING. RAINFALL OF THREE TO SIX
INCHES WAS COMMON ACROSS MUCH OF
CHARLOTTE...HALIFAX...PITTSYLVANIA...AND CAMPBELL COUNTIES.
SEVERAL WATER RESCUES REPORTED FROM DANVILLE CITY AND
PITTSYLVANIA COUNTY. MAIN STEM RIVER FLOODING ALSO ONGOING NOW AS
A RESULT ON THE ROANOKE AT RANDOLPH AND EXPECTED ON THE DAN LATER
TODAY AT SOUTH BOSTON.
THE DRYING EXPECTED A COUPLE OF DAYS AGO WILL BE POSTPONED UNTIL
NEXT WEEK UNFORTUNATELY. THE UPPER LOW TO OUR NORTHWEST WILL STALL
ACROSS WV AND THEN RETROGRADE SLOWLY TO THE WEST INTO KY/TN THROUGH
EARLY NEXT WEEK AS A MAMMOTH UPPER RIDGE EQUALLY RETROGRADE FROM
THE WESTERN ATLANTIC INTO THE MID-ATLANTIC REGION. THIS SHOULD
EVENTUALLY SHUT OFF THE EXCESSIVE RAINFALL AND RETURN US TO MORE
SUMMERLIKE CONDITIONS...BUT UNTIL THEN EXPECT MORE SHOWERS AND
THUNDERSTORMS.
THE GOOD NEWS FOR TODAY IS THAT PWATS ARE DOWN SLIGHTLY...MOSTLY
IN THE 1.5 TO 1.7 INCH RANGE AS OPPOSED TO 2.0+ INCHES. IN
ADDITION...INSTABILITY WILL BE LESS AS EASTERLY FLOW EVOLVES
AROUND THE BUILDING ATLANTIC HIGH. THERE SHOULD BE LESS INTENSE
CONVECTION AND MORE GENERAL STRATIFORM RAIN WITH EMBEDDED HEAVIER
CELLS. NONETHELESS...BECAUSE OF THE EXTREMELY LOW FFG VALUES...IN
SOME CASES LESS THAN 1.0 INCH/HR FOR FLASH FLOODING...HAVE OPTED
TO EXTEND THE FLASH FLOOD WATCH UNTIL 8 AM SATURDAY MORNING. HAVE
REMOVED ALLEGHANY COUNTY WHERE LESS RAINFALL HAS OCCURRED...BUT
ADDED SMYTH COUNTY AS SHRA/TSRA SPREAD IN THAT DIRECTION LATER
TODAY AND TONIGHT. THE MOST FAVORED AREAS AT THIS POINT FOR
ADDITIONAL HEAVY RAINFALL APPEAR TO BE SOUTH OF I-81...MOVING MORE
TOWARD OUR NW NC COUNTIES INTO THE WEEKEND. AS NOTED
ABOVE...HOWEVER...THE MAIN CONCERN IS ARE THE VERY LOW FFG VALUES
AND THE SIMPLE FACT THAT WE CANNOT TAKE HARDLY ANY ADDITIONAL
RAINFALL EAST OF THE ALLEGHANYS AT THIS POINT. THE WV COUNTIES
SHOULD BE JUST FINE AS THEY HAVE NOT HAD A FRACTION OF THE
RAINFALL MANY OF THE VA AND NC COUNTIES HAVE SEEN THE PAST TWO
WEEKS.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE NEAR
TERM...THANKS TO CLOUDS...PCPN...AND EASTERLY FLOW.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AN UPPER LEVEL RIDGE WILL BARREL TO THE WEST OVER THE WEEKEND. THIS
RIDGE WILL BE OFF THE MID ATLANTIC COAST ON SATURDAY THEN OVER THE
OHIO VALLEY BY SUNDAY NIGHT. THIS RIDGE WILL PUSH AN UPPER LEVEL LOW
WESTWARD ACROSS THE TENNESSEE VALLEY TO THE SOUTHERN PLAINS DURING
THE PERIOD. SHORT WAVES AND RAIN AXIS BETWEEN THESE TWO SYSTEMS WILL
BRING A GOOD CHANCE FOR RAIN TO THE REGION ON SATURDAY. WITH AN
EASTERLY UPSLOPE FLOW...HIGHER RAINFALL TOTALS WILL BE ALONG THE
BLUE RIDGE.
THIS RIDGE WILL BRING VERY WARM AND HUMID CONDITIONS TO THE REGION.
85H TEMPERATURES WILL WARM TO +22C BY MONDAY. TEMPERATURES ACROSS
THE MOUNTAIN WILL RANGE FROM THE LOWER TO MID 80S THIS WEEKEND. EAST
OF THE BLUE RIDGE WILL SEE TEMPERATURES APPROACHING 90F.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODEL GUIDANCE HAS COME TO BETTER AGREEMENT ON THE EVOLUTION OF THE
UPPER-LEVEL PATTERN NEXT WEEK WHICH WILL FEATURE A BUILDING UPPER
LEVEL RIDGE OVER THE MID ATLANTIC. THE UPPER LOW WHICH DEVELOPS AND
BREAKS AWAY FROM THE UPPER TROUGH OVER NEW ENGLAND THIS WEEKEND IS
FORECAST TO RETROGRADE AND PUSH WEST-SOUTHWEST REACHING THE
SOUTHERN PLAINS BY THE MIDDLE OF NEXT WEEK...DAY 7.
THIS SUGGESTS LIFT FOR SHOWERS AND STORMS NEXT WEEK WILL BE LIMITED
TO DAYTIME HEATING...THE UPPER LOW MOVING TOO FAR WEST TO BE AN
INFLUENCE. IF THE RIDGE OF HIGH PRESSURE IS AS ROBUST AS FORECAST
597DM...THIS MAY CAUSE ENOUGH WARMING ALOFT TO POTENTIALLY LIMIT
DEEP CONVECTION TO LESS THAN 20 PERCENT COVERAGE EXCEPT FOR MAYBE
THE MOUNTAINS.
MODEL TEMPS HAVE TRENDED WARMER...BUT STILL NOTHING EXTREME. 85H
TEMPS ARE FCST TO BUILD CLOSE TO +20 DEG C BY MID WEEK WHICH SUGGEST
HIGH TEMPS WELL INTO THE 80S...POSSIBLY 90 URBAN AREAS. LOWS SHOULD
ALSO CREEP UPWARD A LITTLE WITH TMINS IN THE 60S TO AROUND 70.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
CLOSED UPPER LOW OVER THE AREA SCHEDULED TO RETROGRADE TO MIDWEST
OVER THE NEXT FEW DAYS. SCT-BKN MVFR CLOUDS WITH POCKETS OF IFR
IN CONVECTION AND AREAS OF FOG.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
EXPECTED THIS AFTERNOON INTO TONIGHT. BELIEVE THE TRENDS WILL BE
SIMILAR TO PREVIOUS DAYS IN A WEAKLY FORCED ENVIRONMENT. KLWB
HAS THE BEST CHANCE OF A THUNDERSTORM THIS AFTERNOON.
AS UPPER LOW BEGINS ITS WWD TREK...A SHORTWAVE WILL DRIFT OVER
THE AREA TONIGHT WITH FLOW BECOMING SELY. THIS SHOULD KEEP
SHOWERS IN THE AREA FOR THE OVERNIGHT. MODELS ALSO SHOW MOISTURE
SUCKING BACK WWD AS THE LOW MOVES...AND THIS SHOULD LEAD TO
IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT.
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
AS OF 120 PM EDT FRIDAY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
RIVER FLOOD WARNING IS CANCELLED FOR THE DAN RIVER NEAR DANVILLE.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN
VIRGINIA...DAN RIVER NEAR PACES...MINOR FLOODING IS FORECAST.
MINOR FLOODING IS ALSO OCCURING ALONG THE ROANOKE RIVER AT
RANDOLPH...DAN RIVER AT SOUTH BOSTON. REFER TO LATEST FLOOD
WARNINGS...RIVER FLOOD WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...RAB/KK
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...PM
AVIATION...MBS/RAB/KK
HYDROLOGY...KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1134 AM EDT FRI JUL 12 2013
.SYNOPSIS...
LOW PRESSURE WILL DRIFT INTO WEST VIRGINIA AND STALL...THEN DRIFT
SLOWLY BACK WEST INTO THE TENNESSEE VALLEY THROUGH EARLY NEXT
WEEK. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD WESTWARD FROM THE
WESTERN ATLANTIC INTO THE MID-ATLANTIC REGION BY EARLY NEXT WEEK.
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE WEEKEND...BUT
SHOULD DIMINISH SOME NEXT WEEK AND BECOME MORE ISOLATED AND
TYPICAL OF SUMMER EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS OVER
THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1110 AM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
KFCX HAS BEEN REPAIRED AND IS BACK IN SERVICE.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
EXPECTED TO DEVELOP THIS AFTERNOON INTO TONIGHT. WITH PWAT STILL
RELATIVELY HIGH...LOW FFG AND VERY WET GROUND...THE POTENTIAL FOR
FLASH FLOODING CONTINUES. HRRR...AND RAP SEEM TO FOCUS ALONG
BLUE RIDGE AND EASTWARD THIS AFTERNOON INTO TONIGHT. UPPER LOW
PROGGED TO MOVE WESTWARD TODAY INTO WEEKEND. MADE SOME MINOR
ADJUSTMENTS IN POPS AND TEMPERATURES FOR THIS AFTERNOON.
MORE LATER....
AS OF 920 AM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
KFCX WILL BE DOWN THROUGH EARLY AFTERNOON FOR EMERGENCY REPAIRS.
PNS OUT WITH RAINFALL TOTALS.
THE 08AM/12Z RNK SOUNDING SHOWED PWATS ARE LOWER AT 1.09 INCHES
WITH NORTHERLY FLOW. INSTABILITY SHOULD BE LESS THIS AFTERNOON AS
MORE EASTERLY FLOW EVOLVES AROUND THE BUILDING ATLANTIC HIGH. BUT
WITH THE UPPER LOW...CONVECTION WITH POCKETS OF HEAVY RAIN WILL
DEVELOP THIS AFTERNOON INTO TONIGHT. THE THREAT FOR FLASH FLOODING
CONTINUES TODAY BECAUSE OF THE EXTREMELY LOW FFG VALUES...IN SOME
CASES LESS THAN 1.0 INCH/HR FOR FLASH FLOODING. ADJUSTED
TEMPERATURES AND DEWPOINTS FOR LATE MORNING INTO THIS AFTERNOON.
MODIFIED POPS INTO EARLY THIS AFTERNOON. WILL MAKE MORE
ADJUSTMENTS AS MORNING PROGRESSES.
AS OF 500 AM EDT FRIDAY...
FLASH FLOOD WATCH HAS BEEN EXTENDED UNTIL 8 AM SATURDAY MORNING.
EXCESSIVE RAINFALL IN PARTS OF THE FORECAST AREA THIS MORNING AS
UPPER LOW JUST TO OUR NORTHWEST COMBINED WITH VERY TROPICAL AIR
MASS ACROSS THE PIEDMONT CONTINUES. TRAINING AND BACKBUILDING
THUNDERSTORMS BROUGHT RECORD RAINFALL AMOUNTS TO DANVILLE
OVERNIGHT...WITH OVER FOUR INCHES OF RAIN AT THE DANVILLE AIRPORT
SINCE ABOUT 10 PM THURSDAY EVENING. RAINFALL OF THREE TO SIX
INCHES WAS COMMON ACROSS MUCH OF
CHARLOTTE...HALIFAX...PITTSYLVANIA...AND CAMPBELL COUNTIES.
SEVERAL WATER RESCUES REPORTED FROM DANVILLE CITY AND
PITTSYLVANIA COUNTY. MAIN STEM RIVER FLOODING ALSO ONGOING NOW AS
A RESULT ON THE ROANOKE AT RANDOLPH AND EXPECTED ON THE DAN LATER
TODAY AT SOUTH BOSTON.
THE DRYING EXPECTED A COUPLE OF DAYS AGO WILL BE POSTPONED UNTIL
NEXT WEEK UNFORTUNATELY. THE UPPER LOW TO OUR NORTHWEST WILL STALL
ACROSS WV AND THEN RETROGRADE SLOWLY TO THE WEST INTO KY/TN THROUGH
EARLY NEXT WEEK AS A MAMMOTH UPPER RIDGE EQUALLY RETROGRADE FROM
THE WESTERN ATLANTIC INTO THE MID-ATLANTIC REGION. THIS SHOULD
EVENTUALLY SHUT OFF THE EXCESSIVE RAINFALL AND RETURN US TO MORE
SUMMERLIKE CONDITIONS...BUT UNTIL THEN EXPECT MORE SHOWERS AND
THUNDERSTORMS.
THE GOOD NEWS FOR TODAY IS THAT PWATS ARE DOWN SLIGHTLY...MOSTLY
IN THE 1.5 TO 1.7 INCH RANGE AS OPPOSED TO 2.0+ INCHES. IN
ADDITION...INSTABILITY WILL BE LESS AS EASTERLY FLOW EVOLVES
AROUND THE BUILDING ATLANTIC HIGH. THERE SHOULD BE LESS INTENSE
CONVECTION AND MORE GENERAL STRATIFORM RAIN WITH EMBEDDED HEAVIER
CELLS. NONETHELESS...BECAUSE OF THE EXTREMELY LOW FFG VALUES...IN
SOME CASES LESS THAN 1.0 INCH/HR FOR FLASH FLOODING...HAVE OPTED
TO EXTEND THE FLASH FLOOD WATCH UNTIL 8 AM SATURDAY MORNING. HAVE
REMOVED ALLEGHANY COUNTY WHERE LESS RAINFALL HAS OCCURRED...BUT
ADDED SMYTH COUNTY AS SHRA/TSRA SPREAD IN THAT DIRECTION LATER
TODAY AND TONIGHT. THE MOST FAVORED AREAS AT THIS POINT FOR
ADDITIONAL HEAVY RAINFALL APPEAR TO BE SOUTH OF I-81...MOVING MORE
TOWARD OUR NW NC COUNTIES INTO THE WEEKEND. AS NOTED
ABOVE...HOWEVER...THE MAIN CONCERN IS ARE THE VERY LOW FFG VALUES
AND THE SIMPLE FACT THAT WE CANNOT TAKE HARDLY ANY ADDITIONAL
RAINFALL EAST OF THE ALLEGHANYS AT THIS POINT. THE WV COUNTIES
SHOULD BE JUST FINE AS THEY HAVE NOT HAD A FRACTION OF THE
RAINFALL MANY OF THE VA AND NC COUNTIES HAVE SEEN THE PAST TWO
WEEKS.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE NEAR
TERM...THANKS TO CLOUDS...PCPN...AND EASTERLY FLOW.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AN UPPER LEVEL RIDGE WILL BARREL TO THE WEST OVER THE WEEKEND. THIS
RIDGE WILL BE OFF THE MID ATLANTIC COAST ON SATURDAY THEN OVER THE
OHIO VALLEY BY SUNDAY NIGHT. THIS RIDGE WILL PUSH AN UPPER LEVEL LOW
WESTWARD ACROSS THE TENNESSEE VALLEY TO THE SOUTHERN PLAINS DURING
THE PERIOD. SHORT WAVES AND RAIN AXIS BETWEEN THESE TWO SYSTEMS WILL
BRING A GOOD CHANCE FOR RAIN TO THE REGION ON SATURDAY. WITH AN
EASTERLY UPSLOPE FLOW...HIGHER RAINFALL TOTALS WILL BE ALONG THE
BLUE RIDGE.
THIS RIDGE WILL BRING VERY WARM AND HUMID CONDITIONS TO THE REGION.
85H TEMPERATURES WILL WARM TO +22C BY MONDAY. TEMPERATURES ACROSS
THE MOUNTAIN WILL RANGE FROM THE LOWER TO MID 80S THIS WEEKEND. EAST
OF THE BLUE RIDGE WILL SEE TEMPERATURES APPROACHING 90F.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODEL GUIDANCE HAS COME TO BETTER AGREEMENT ON THE EVOLUTION OF THE
UPPER-LEVEL PATTERN NEXT WEEK WHICH WILL FEATURE A BUILDING UPPER
LEVEL RIDGE OVER THE MID ATLANTIC. THE UPPER LOW WHICH DEVELOPS AND
BREAKS AWAY FROM THE UPPER TROUGH OVER NEW ENGLAND THIS WEEKEND IS
FORECAST TO RETROGRADE AND PUSH WEST-SOUTHWEST REACHING THE
SOUTHERN PLAINS BY THE MIDDLE OF NEXT WEEK...DAY 7.
THIS SUGGESTS LIFT FOR SHOWERS AND STORMS NEXT WEEK WILL BE LIMITED
TO DAYTIME HEATING...THE UPPER LOW MOVING TOO FAR WEST TO BE AN
INFLUENCE. IF THE RIDGE OF HIGH PRESSURE IS AS ROBUST AS FORECAST
597DM...THIS MAY CAUSE ENOUGH WARMING ALOFT TO POTENTIALLY LIMIT
DEEP CONVECTION TO LESS THAN 20 PERCENT COVERAGE EXCEPT FOR MAYBE
THE MOUNTAINS.
MODEL TEMPS HAVE TRENDED WARMER...BUT STILL NOTHING EXTREME. 85H
TEMPS ARE FCST TO BUILD CLOSE TO +20 DEG C BY MID WEEK WHICH SUGGEST
HIGH TEMPS WELL INTO THE 80S...POSSIBLY 90 URBAN AREAS. LOWS SHOULD
ALSO CREEP UPWARD A LITTLE WITH TMINS IN THE 60S TO AROUND 70.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 730AM EDT FRIDAY...
BIZARRE SUMMER PATTERN WITH CLOSED UPPER LOW OVER THE AREA SCHEDULED TO
RETROGRADE TO MIDWEST OVER THE NEXT FEW DAYS. EXPECT LOW CLOUDS/FOG TO
BREAK UP LATER THIS MORNING WITH START OF DAYTIME HEATING...THOUGH EXPECTING
CIGS TO REMAIN MVFR FOR KLWB AND KBLF AS UPPER LOW AND TERRAIN INFLUENCES
HELP ENHANCE LIFT AND GENERATE SHOWERS. EXPECT A MORE DIURNAL FLAVOR TO
CIGS AND WEATHER AT OTHER LOCATIONS WITH SOME SHOWERS AND THUNDERSTORMS
REDEVELOPING THIS AFTERNOON. BELIEVE THE TRENDS WILL BE SIMILAR TO PREVIOUS
DAYS IN A WEAKLY FORCED ENVIRONMENT. DO NOT SEE ANY PARTICULAR FEATURES TO FOCUS
OR TIME CONVECIVE DEVELOPMENT SO WILL KEEP KBCB...KROA..KLYH...AND KDAY DRY EARLY
AND USE VICINITY AFTER 18Z.
AS UPPER LOW BEGINS ITS WWD TREK...A SHORT WAVE WILL DRIFT OVER THE AREA TONIGHT
WITH FLOW BECOMING SELY. HIS SHOULD KEEP SHOWERS IN THE AREA FOR THE OVERNIGHT.
MODELS ALSO SHOW MOISTURE SUCKING BACK WWD AS THE LOW MOVES...AND THIS SHOULD LEAD
TO IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT.
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN VIRGINIA...DAN
RIVER NEAR PACES AFFECTING HALIFAX COUNTY FOR THE DAN RIVER...INCLUDING
PACES...MINOR FLOODING IS FORECAST. MINOR FLOODING IS ALSO OCCURING
ALONG THE ROANOKE RIVER AT RANDOLPH...DAN RIVER AT DANVILLE AND
SOUTH BOSTON. REFER TO LATEST FLOOD WARNINGS...RIVER FLOOD
WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...RAB/KK
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...PM
AVIATION...MBS/RAB
HYDROLOGY...KK/RAB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
218 AM CDT SUN JUL 14 2013
.DISCUSSION...
903 PM CDT
CURRENT GRIDS/FORECAST IN GOOD SHAPE. MADE MINOR TWEAKS TO
TEMPS...DEW POINTS AND SKY GRIDS TO FIT CURRENT TRENDS. A FEW
PASSING CLOUDS FAR SOUTHERN PART OF FORECAST AREA ASSOCIATED WITH
WESTWARD MOVING UPPER LOW...OTHERWISE CLEAR SKIES EXPECTED THROUGH
THE OVERNIGHT. WITH LIGHT WINDS...SLOWLY INCREASING DEW POINTS AND
STAGNANT AIR MASS...SOME LIGHT HAZE CAN BE EXPECTED AROUND
SUNRISE...AWAY FROM THE CITY HEAT ISLAND...BUT NOT SIGNIFICANT
ENOUGH TO MENTION IN FORECAST AT THIS TIME.
ALLSOPP
//PREV DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NONE.
RATZER
//DISCUSSION...UPDATED 06Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD...THOUGH SOME
MVFR HAZE IS POSSIBLE THROUGH SUNRISE MAINLY AT GYY/DPA/RFD AWAY
FROM WARMER CORE OF CHICAGO. PERSISTENT HIGH PRESSURE RIDGE WILL
AGAIN SUPPORT LIGHT WINDS...WITH A LAKE BREEZE PRODUCING EASTERLY
WINDS AROUND 10 KT WITH A FEW HIGHER GUSTS THIS AFTERNOON. SOME
MODEL GUIDANCE SUGGESTING ISOLATED SHRA/TSRA LATE THIS
AFTERNOON...THOUGH MODEL DEW POINT TEMPS AND RESULTING INSTABILITY
APPEAR OVERDONE AND NOT MUCH SUPPORT ALOFT WITH BUILDING UPPER
RIDGE.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE ALL FORECAST ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH THURSDAY...GENERALLY PREVAILING VFR...HOWEVER AN
AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ANY DAY.
FRIDAY...CHANCE OF THUNDERSTORMS.
IZZI
&&
.MARINE...
217 AM CDT
A PERIOD OF LIGHT WINDS WILL CONTINUE ACROSS LAKE MICHIGAN THROUGH
MONDAY NIGHT...AS THE WESTERN PERIPHERY OF AN ELONGATED AREA OF HIGH
PRESSURE RIDGE REMAINS ACROSS THE AREA. THE CENTER OF THE HIGH WAS
ACTUALLY OFF THE JERSEY SHORE EARLY THIS MORNING...BUT WILL DEVELOP
WEST INTO THE MID-ATLANTIC REGION TONIGHT AND ACROSS THE OHIO VALLEY
AND SOUTHERN GREAT LAKES REGION THROUGH MID-WEEK. A FAIRLY DEEP AREA
OF LOW PRESSURE WILL EVENTUALLY DEVELOP ACROSS NORTHERN MANITOBA
TUESDAY...INCREASING SOUTH-SOUTHWEST WINDS A BIT ACROSS LAKE
MICHIGAN...AND WILL MOVE NORTHEAST ACROSS HUDSON BAY AND INTO
NORTHERN QUEBEC BY THURSDAY. THIS LOW WILL TRAIL A COLD FRONT ACROSS
THE NORTHERN LAKES...WHICH WILL EVENTUALLY SETTLE ACROSS LAKE
MICHIGAN FRIDAY OR FRIDAY NIGHT. THUNDERSTORM CHANCES WILL INCREASE
MID-LATE WEEK AHEAD OF THIS FRONT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1222 AM CDT SUN JUL 14 2013
.DISCUSSION...
903 PM CDT
CURRENT GRIDS/FORECAST IN GOOD SHAPE. MADE MINOR TWEAKS TO
TEMPS...DEW POINTS AND SKY GRIDS TO FIT CURRENT TRENDS. A FEW
PASSING CLOUDS FAR SOUTHERN PART OF FORECAST AREA ASSOCIATED WITH
WESTWARD MOVING UPPER LOW...OTHERWISE CLEAR SKIES EXPECTED THROUGH
THE OVERNIGHT. WITH LIGHT WINDS...SLOWLY INCREASING DEW POINTS AND
STAGNANT AIR MASS...SOME LIGHT HAZE CAN BE EXPECTED AROUND
SUNRISE...AWAY FROM THE CITY HEAT ISLAND...BUT NOT SIGNIFICANT
ENOUGH TO MENTION IN FORECAST AT THIS TIME.
ALLSOPP
//PREV DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NONE.
RATZER
//DISCUSSION...UPDATED 06Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD...THOUGH SOME
MVFR HAZE IS POSSIBLE THROUGH SUNRISE MAINLY AT GYY/DPA/RFD AWAY
FROM WARMER CORE OF CHICAGO. PERSISTENT HIGH PRESSURE RIDGE WILL
AGAIN SUPPORT LIGHT WINDS...WITH A LAKE BREEZE PRODUCING EASTERLY
WINDS AROUND 10 KT WITH A FEW HIGHER GUSTS THIS AFTERNOON. SOME
MODEL GUIDANCE SUGGESTING ISOLATED SHRA/TSRA LATE THIS
AFTERNOON...THOUGH MODEL DEW POINT TEMPS AND RESULTING INSTABILITY
APPEAR OVERDONE AND NOT MUCH SUPPORT ALOFT WITH BUILDING UPPER
RIDGE.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE ALL FORECAST ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH THURSDAY...GENERALLY PREVAILING VFR...HOWEVER AN
AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ANY DAY.
FRIDAY...CHANCE OF THUNDERSTORMS.
IZZI
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1135 PM MDT SAT JUL 13 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 595DM RIDGE CENTERED OVER
TX/OK PANHANDLES WITH AXIS EXTENDING INTO THE NORTHERN PLAINS. A
CLOSED 578DM LOW OVER THE EASTERN OH RIVER VALLEY IS JUST DOWN
STREAM OF THIS FEATURE...WITH THE REMNANTS OF OVERNIGHT CONVECTION
IN THE NORTHERN PLAINS BEGINNING TO BECOME WRAPPED INTO THE FLOW
BETWEEN THESE FEATURES. A SHORTWAVE TROUGH IS CURRENTLY IN PLACE
OVER NE COLORADO...WITH THUNDERSTORMS ALREADY BEGINNING TO DEVELOP
OVER HIGHER TERRAIN IN ON WESTERN EXTENT OF THIS FEATURE. A SURFACE
TROUGH IS CURRENTLY CENTERED OVER THE NE PART OF OUR CWA AND EXTENDS
SOUTH AND WEST INTO SOUTHEAST COLORADO.
TD VALUES HAVE MIXED DOWN OVER EASTERN PARTS OF THE CWA...RESULTING
IN SLIGHTLY LOWER HEAT INDICES THAN ORIGINALLY ANTICIPATED. AT THE
SAME TIME CRITERIA IS BEING MET AT NORTON...AND WE HAVENT REACHED
PEAK HEATING YET...SO WILL PLAN ON LEAVING HEAT ADVISORY AS IS.
GUIDANCE CONTINUES TO SUPPORT THUNDERSTORMS INITIATING ALONG AND
BEHIND THE SURFACE TROUGH OVER OUR CWA...WITH BETTER COVERAGE CLOSER
TO H7/H5 SHORTWAVE TROUGH IN NORTHEAST COLORADO. LATEST RAP ANALYSIS
SHOWS AXIS OF 1500-2000 J/KG ML CAPE EXTENDING ACROSS CWA. SHEAR ISNT
VERY IMPRESSIVE...BUT WITH INVERTED V AND GOOD MOISTURE ABOVE DRY
LAYER STRONG GUSTS WILL BE A CONCERN WITH ANY THUNDERSTORMS.
GUIDANCE ACTUALLY SHOWS ACTIVITY CONTINUE THROUGH MOST OF THE
NIGHT...HOWEVER WITH SHORTWAVE WEAKENING AND MOVING NORTH AND EAST
IM LESS CONFIDENT IN THIS ACTIVITY LINGERING PAST 06Z.
CLOSED LOW OVER OH RIVER VALLEY WITH MOVE EAST INTO THE SOUTHERN
PLAINS SUNDAY WITH DEEP EASTERLY FLOW DEVELOPING ACROSS THE
CWA...AND COLD FRONT MOVING INTO THE REGION FROM THE SOUTHEAST LATE
IN THE AFTERNOON. BEST CONVERGENCE/LARGE SCALE ASCENT WILL LIKELY BE
ALONG FRONT RANGE EXTENDING INTO OUR EASTERN CO COUNTIES WHERE AXIS
OF STRONG VORTICITY ON NW QUAD OF UPPER LOW WILL COMBINE WITH STRONG
UPSLOPE TO PRODUCE SHOWERS AND THUNDERSTORMS. GUIDANCE CONTINUES TO
SHOW DECENT INSTABILITY IN PLACE...AND WITH PWATS IN EXCESS OF 1.5
INCHES WE COULD SEE NUMEROUS THUNDERSTORMS WITH HEAVY RAIN. I
TRENDED POPS UP DURING THE AFTERNOON TO LIKELY CATEGORY DURING
AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
SUNDAY EVENING THE FRONT WILL CONTINUE TO MOVE WEST...WITH THE
BEST INSTABILITY AND LIFT REMAINING OVER THE TROUGH. WITH LITTLE
CIHN TO HOLD BACK CONVECTION AND SURFACE CONVERGENCE SERVING AS A
TRIGGER...STORMS SHOULD NOT HAVE MUCH PROBLEM DEVELOPING. THE BEST
CHANCE FOR STORM DEVELOPMENT WILL BE OVER THE EAST CENTRAL
COLORADO AND PARTS OF FAR SOUTHWEST NEBRASKA WITH PRECIP. CHANCES
DECLINING TO THE EAST AS LIFT AND INSTABILITY TAPER OFF. AS THE
EVENING PROGRESSES THE SURFACE TROUGH WILL GRADUALLY MOVE WEST OUT
OF THE AREA...WITH BE BETTER PRECIP. CHANCES FOLLOWING IT.
MEANWHILE DRIER MORE STABLE AIR WILL BE MOVING IN FROM THE EAST
ACCOMPANYING AN INVERTED SURFACE RIDGE. THE DRIER AIR WILL HAVE
MOVED ACROSS ENTIRE AREA BY LATE IN THE NIGHT.
STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE NORTHWEST PART OF
THE AREA NEAR THE SURFACE TROUGH WHERE A CORRIDOR OF MIXED 1KM MOST
UNSTABLE CAPE IN EXCESS OF 2000J/KG WILL BE LOCATED. THE LIMITING
FACTOR WILL BE THE LOW 0-6KM SHEAR OF 15-20KTS...WHICH MAY BE
ENOUGH FOR AN ISOLATED SUPERCELL TO DEVELOP GIVEN THE ADEQUATE CAPE.
MEAN STORM MOTIONS WILL BE TO THE SOUTHEAST OVER EAST CENTRAL
COLORADO...SO THERE MAY BE SOME TRAINING ALONG THE SURFACE TROUGH
LEADING TO LOCALLY HEAVY RAINFALL IN THE EVENING.
MONDAY THE SURFACE RIDGE SLIDES SOUTH AS ANOTHER WAVE OF MOISTURE
MOVES OVER THE SOUTHERN HALF OF THE AREA AROUND THE UPPER LEVEL LOW
TO THE SOUTH DURING THE AFTERNOON. TOWARD LATE AFTERNOON A WAVE OF WEAK
LIFT DEVELOPS OVER THE FAR SOUTHERN PART OF THE AREA...THEN
DISSIPATES BY EARLY EVENING. THIS MAY BE ENOUGH LIFT FOR AN
ISOLATED STORM TO DEVELOP.
TUESDAY THROUGH SATURDAY WILL BE DRY FOR THE MAJORITY OF THE PERIOD
AS THE UPPER LEVEL RIDGE OVER THE EAST CONUS BUILDS WEST AND BECOMES
ESTABLISHED OVER THE WESTERN CONUS TOWARD THE END OF THE WORK WEEK.
DURING THE WEEKEND AN UPPER LEVEL SHORT WAVE TROUGH DEVELOPS OVER
THE NORTHERN ROCKIES AND MOVES SOUTHEAST OVER THE AREA. A COLD
FRONT WILL ACCOMPANY THE UPPER LEVEL FEATURE WHICH WILL AID THE LIFT
OF THE TROUGH. BEING A WEEK OUT THERE IS STILL A GOOD DEAL OF
UNCERTAINTY AS TO WHERE THE TROUGH WILL TRACK AND IF IT WILL BE DEEP
ENOUGH TO DEVELOP STORMS. WOULD NOT TAKE TOO MUCH OF A SHIFT IN THE
POSITION OF THE RIDGE OVER THE ROCKIES TO PUSH THE UPPER LEVEL
TROUGH NORTH OF THE AREA. AS SUCH WILL LEAVE PRECIP. CHANCES JUST
BELOW 50% FOR THE ENTIRE AREA FOR SATURDAY. HIGH TEMPERATURES FOR
THE PERIOD WILL GRADUALLY WARM AS THE RIDGE BUILDS EAST. NEAR
NORMAL VALUES THROUGH MID WEEK WILL WARM TO ABOVE NORMAL BY FRIDAY
WITH HIGHS RANGING FROM BELOW TO ABOVE NORMAL SATURDAY AS THE COLD
FRONT MOVES THROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM MDT SAT JUL 13 2013
VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE
OVERNIGHT HOURS...BUT FLIGHT CATEGORIES WILL BE LOWERING THROUGH
THE DAY ON SUNDAY WITH PRECIPITATION OVERSPREADING THE AREA.
OVERNIGHT...THERE ARE NUMEROUS OUTFLOW BOUNDARIES ASSOCIATED WITH
THUNDERSTORMS IN THE REGION...WIND DIRECTIONS MAY BE HIGHLY
VARIABLE THROUGH THE OVERNIGHT...AND CANNOT COMPLETELY RULE OUT A
BRIEF SHOWER OR THUNDERSTORM...BUT RECENT TRENDS SUGGESTS THEY
WILL NOT IMPACT EITHER TERMINAL FOR THE NEXT FEW HOURS.
SUNDAY...UNUSUAL PATTERN WITH AN UPPER LOW MOVING INTO OKLAHOMA
FROM THE EAST THIS AFTERNOON. PRECIPITATION WILL BE WRAPPING
AROUND THE SYSTEM FROM THE NORTH WITH RAIN AND EMBEDDED
THUNDERSTORMS DEVELOPING AS EARLY AS SUNDAY MORNING AND CONTINUING
THROUGH MOST OF THE DAY. CIGS WILL BE LOWERING AS WELL AS POSSIBLE
VISIBILITY RESTRICTIONS DUE TO RAIN AT BOTH KGLD AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DJR
LONG TERM...JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
315 AM EDT SUN JUL 14 2013
.SHORT TERM (Today through Monday)...
Issued at 300 AM EDT Sun Jul 14 2013
The short term period will continue the retrograding pattern with
the upper low now over southeastern Missouri moving west-southwest
to the southern Plains by tonight and Monday, as the upper high now
to our northeast expands westward into the Ohio Valley. In this
pattern, the best chance for convection will be today as a moisture
stream moves northwest between the upper low and high, with
suppressed chances on Monday.
In the near term, skies are clear to partly cloudy over central
Kentucky and southern Indiana, and this will hold through the
morning hours. Isolated showers early over parts of Larue and Hardin
counties have dissipated, and no more than an isolated shower or two
should still pop up elsewhere early this morning if at all. Patchy
fog could develop in a few river valleys by daybreak, otherwise
should not be much of a problem.
During the day today, the moisture stream in the short term models
shows precipitable water values of 1.5 to 2 inches with deep enough
moisture for scattered convective development this afternoon along
any mesoscale or cloud-clear type boundaries. It is difficult to pin
down at this time where cells might develop, although it appears
western parts of south-central Kentucky will have the best chance as
moisture streams up through the Tennessee Valley toward western
Kentucky. This would mean our northeastern counties might only see
isolated cells. This scenario is shown by the HRRR model, although
our in-house WRF develops scattered convection more over our
southeastern counties then propagates them northwest into north-
central Kentucky late this afternoon. Grids will reflect the HRRR,
which is supported by the NAM and GFS as well. In any storms, hail
should be less of a concern today than on Saturday given higher
temperatures aloft, although brief very heavy rain would be more
likely to occur along with CG lightning.
Any diurnal storms should die off this evening with a stabilizing
boundary layer. Skies should also become clear to partly cloudy
again. Patchy fog could develop late tonight in river valleys and
where any rain falls this afternoon.
On Monday, as the upper high builds in and heights and
temperatures aloft rise a bit, and as low-level moisture becomes a
little less prevalent, convection will be more hard pressed to
develop in the afternoon. As a result, while an isolated cell or two
could occur, the chances appear too small to include in the
forecast. Will go with a dry forecast under a partly cloudy sky.
High temperatures today should reach the upper 80s in many areas,
locally held down where showers occur. On Monday, highs should be
around 90 or the lower 90s in most areas, with maximum afternoon
heat indices in the mid to perhaps upper 90s.
.LONG TERM (Monday Night through Saturday)...
Issued at 300 AM EDT Sun Jul 14 2013
Most of the upcoming week will degenerate into a broken record of a
forecast, as an anomalously strong upper ridge parks itself over the
Ohio Valley. Main sources of uncertainty center on convective
potential, and whether it will be the heat or the humidity making it
feel like close to 100 degrees each afternoon.
The atmosphere will be quite juicy with PWATs slightly above climo,
providing moderate to strong instability. Limiting factors will be
mid-level warming associated with the ridge, as H7 temps will run
10-11C, and the lack of any synoptic forcing. Convection will be
limited to diurnal activity, with probabilities below mentionable
thresholds in the north for much of the week. Highest POPs will be
in the low-end chance category, and confined to areas south of the
Western Kentucky and Bluegrass Parkways.
Temps are a bit of a crapshoot, as the moist ground is likely to
limit our warming at least in the first part of the week. Max temp
forecast undercuts extended GFS MOS by a few degrees, but still
expect to reach at least the lower 90s. Could see our heating catch
up with guidance later in the week as the heat dries out the ground.
Dewpoints in the lower 70s will push heat indices close to 100, but
any warmer temps will likely be offset by deeper mixing and slightly
lower dewpoints, so confidence is higher in the heat index forecast
than the actual temp or dewpoint forecast. Mins solidly above climo
in the lower to mid 70s each night.
POPs will increase as we head into the weekend, with a solid chance
on Saturday as the ridge starts to break down and we come under more
influence of the westerlies.
&&
.AVIATION (06Z TAF Update)...
Issued at 120 AM EDT Sun Jul 14 2013
As the upper low moves westward into Missouri, low-to-mid-level
moisture continues to stream northwestward to its east. Isolated
showers are possible from 06-12z although should not affect any TAF
sites. With somewhat higher surface dewpoints and clear to partly
cloudy skies, there could be patchy fog around daybreak which could
affect BWG and/or LEX with possible MVFR conditions at times from
about 10-13z (will monitor any fog development). Otherwise,
sufficient moisture and instability should be present on Sunday for
isolated to scattered convective development, mainly in afternoon,
with BWG most susceptible and probably LEX least susceptible. Will
carry VCTS at each site. Conditions should be VFR on Sunday, except
briefly lower if a cell impacts the site. Any convective cells
should weaken/dissipate around 00z, with VFR conditions thereafter.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......TWF
Long Term........RAS
Aviation.........TWF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
410 AM EDT SUN JUL 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH EARLY NEXT
WEEK WHILE A WEAK COLD FRONT IS EXPECTED TO CROSS THE AREA ON
MONDAY. A STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST
LATER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONTINUED WARM AND DRY THIS TERM. A LARGE RIDGE OF HIGH PRES
WILL REMAIN IN CONTROL W/ANOTHER DAY OF VERY WARM TEMPERATURES.
LATEST SATL IR IMAGERY SHOWED SOME MID AND HIGH CLOUDS ROLLING
OVER THE UPPER RIDGE INTO PORTIONS OF NORTHERN AND EASTERN MAINE.
THE 00Z UA SHOWED A 50KT JETLET IN THE UPPER LEVELS ACROSS QUEBEC
AIDING IN THE CLOUDS PUSHING TOWARD THE CROWN OF MAINE. SOME STRATUS
AND FOG DEVELOPING OVER SWRN MAINE NEAR THE WATERVILLE AREA AND
ANOTHER BATCH SITTING OFF THE MAINE. SATL LOOP SHOWED THIS STRATUS
AND FOG SLOWLY EDGING NORTHWARD TOWARD THE THE DOWNEAST AND COAST.
DECIDED TO ADD SOME PATCHY FOR THE INTERIOR DONWEAST AND THE
COAST. STRATUS AND FOG WILL LIFT AND BURN AFTER SUNRISE THIS
MORNING. THE LATEST HRRR AND LAMP GUIDANCE DOING QUITE WELL W/THE
TEMPERATURE PROFILE ATTM PER THE 06Z OBS AND HAVE LEANED THIS WAY
FOR THE DAYTIME HIGHS TODAY WHICH SHOWS UPPER 80S TO AROUND 90
AWAY FROM THE COAST. COASTAL AREAS WILL BE COOLER DUE TO A SEA
BREEZE BUT STILL LOW TO MID 80S BEFORE THE BREEZE SETS UP.
THERE IS THE POTENTIAL FOR SOME FOG AGAIN LATER TONIGHT ESPECIALLY
FOR THE DOWNEAST AND COASTAL AREAS. THE LATEST NAM AND GFS
SOUNDINGS PICK THIS UP WELL W/AN INVERSION SETTING UP AND MOISTURE
TRAPPED RIGHT AT THE BLYR. TEMPERATURES OVERNIGHT WILL BE A TAD
WARMER THAN SATURDAY NIGHT W/READINGS EXPECTED TO BE IN THE LOW TO
MID 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A STRONG UPPER LEVEL RIDGE WILL BUILD WESTWARD FROM THE MID
ATLANTIC REGION AND BE CENTERED NEAR THE OH/IN BORDER BY 00Z TUE.
THIS WILL KEEP A WESTERLY FLOW OF VERY WARM AIR ACROSS THE REGION
ON MONDAY. H85 TEMPS OF +17 TO +18 C WITH H925 TEMPS +23 TO +25 C.
EXPECT HIGH TEMPERATURES ON MONDAY TO RANGE FROM THE UPPER 80S TO
LOWER 90S ACROSS MUCH OF THE REGION AWAY FROM THE COAST. A WEAK
COLD FRONT WILL CROSS THE REGION DURING MONDAY AFTERNOON BUT WITH
LITTLE IN THE WAY OF MOISTURE NOT EXPECTING ANYTHING MORE THAN
SOME INCREASING CLOUDS WITH THE PASSAGE OF THE FRONT. EXPECT
MAINLY CLEAR SKIES MONDAY NIGHT WITH LOW TEMPERATURES MAINLY IN
THE 60S. TUESDAY WILL BE ANOTHER MAINLY DRY DAY BUT IT WILL BE A
TAD COOLER THAN MONDAY WITH HIGH TEMPERATURES GENERALLY IN THE LOW
TO MID 80S NORTH AND NEAR 90 DEGREES ACROSS CENTRAL AND INTERIOR
DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE STRONG UPPER RIDGE WILL CONTINUE TO BUILD WESTWARD AND BE CENTERED
NEAR IL BY 00Z THU. AS THE UPPER RIDGE BUILDS WEST THE UPPER FLOW
ACROSS OUR AREA WILL BECOME MORE ZONAL DURING WEDNESDAY ALLOWING A
COLD FRONT TO CROSS THE REGION LATER WEDNESDAY AND WEDNESDAY
EVENING. LOOKS LIKE THE STAGE COULD BE SET FOR STRONG TO POSSIBLY
SEVERE CONVECTION TO DEVELOP WEDNESDAY AFTERNOON. STILL WAY TO EARLY
FOR ANY MENTION OF ENHANCED WORDING AT THIS TIME BUT THE THREAT WILL
NEED TO BE MONITORED.
THE FRONT WILL MOVE EAST OF THE COAST BY EARLY THURSDAY MORNING AS
COOLER AND DRIER AIR BUILD IN AS HIGH PRESSURE BUILDS EAST. A ZONAL
FLOW WILL KEEP THE CHANCE FOR SHOWERS IN THE FORECAST FOR MUCH OF
THE REMAINDER OF THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL
LEVELS.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR THROUGH TONIGHT W/THE EXCEPTION FOR KBGR AND KBHB
AS SOME SHALLOW FOG COULD ALLOW FOR MVFR AND POSSIBLY IFR BRIEFLY
EARLY SUNDAY MORNING.
SHORT TERM: MAINLY VFR MONDAY AND TUESDAY. A COLD FRONT WILL CROSS
THE REGION LATER WEDNESDAY AND WEDNESDAY EVENING. CONFIDENCE IS
INCREASING FOR WIDESPREAD THUNDERSTORMS TO DEVELOP IN ADVANCE OF
THE FRONT WEDNESDAY AFTERNOON RESULTING ON PERIODS OF MVFR/IFR
CONDITIONS IN AND HEAVIER SHOWERS/THUNDERSTORMS. MAINLY VFR
RETURNS FOR THURSDAY.
&&
.MARINE...
NEAR TERM: A SWELL WILL CONTINUE THROUGH TONIGHT W/WAVE HEIGHTS OF
2 FT. WINDS WILL BE LIGHT AVERAGING SPEEDS OF LESS THAN 10 KTS.
SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EDT SUN JUL 14 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG
EXTENDING WWD FM THE NE CONUS THRU THE GREAT LKS ON THE SE FLANK OF
FASTER WSW FLOW ALF OVER CANADA. 00Z APX RAOB SHOWS A STABLE...BONE
DRY AIRMASS /PWAT 0.77 INCH/ CLOSER TOWARD THE CORE OF THIS UPR RDG.
SO THE SE HALF OF THE CWA IS MOCLR. FARTHER TO THE W...THERE IS A
BAND OF MAINLY MID CLDS STRETCHING FM THE NW HALF OF LK SUP SWWD
THRU MN AND INTO IOWA. IN FACT...THE 00Z MPX RAOB SHOWS A GOOD DEAL
OF MID LVL MSTR WITH PWAT 1.93 INCH...188 PCT OF NORMAL. BUT AN
ABSENCE OF ANY SGNFT DYNAMIC FORCING UNDER THE UPR RDG AXIS WITH THE
00Z GRB/MPX RAOBS INDICATING A CAPPING INVRN THAT WEAKENS A BIT
FARTHER TO THE W AWAY FM THE HIER HGTS HAS IS ALLOWING FOR ONLY SOME
ISOLD -SHRA OVER MAINLY WRN UPR MI AND NW WI WHERE THE RUC ANALYSIS
SHOWS A BIT HIER H7 DEWPTS NEAR 10C. ANOTHER FACTOR TENDING TO
RESTRICT THE SHRA COVERAGE/INTENSITY IS A FEED OF DRIER SFC-H85 AIR
FM THE S SHOWN ON THE 00Z QUAD CITIES IOWA RAOB. SPC MESOANALYSIS
INDICATES MUCAPE NOT MUCH HIER THAN 100-250 J/KG. FARTHER TO THE
NW...A FAIRLY POTENT SHRTWV JUST W OF LK WINNIPEG EMBEDDED IN THE
WSW FLOW ALF OVER CANADA IS CAUSING SOME SCT SHRA/TS UNDER AXIS OF
GREATER INSTABILITY OVER NDAKOTA/FAR NW MN. BUT VERY DRY AIRMASS
SHOWN ON THE 00Z INL RAOB IS LIMITING THE EWD PUSH OF THESE SHRA.
TODAY...AS THE UPR RDG AXIS EXPANDS TO THE W AND H7 HGTS RISE
ACCORDINGLY...MODELS IN GOOD AGREEMENT SHOWING SE EDGE OF HIER H7
DEWPTS RETREATING SLOWLY TO THE NW AS WELL. LOWER H85 DEWPTS
ARRIVING FM THE S WL ALSO TEND TO END ANY SHRA. SO WL FCST LINGERING
POPS OVER THE NW LAND CWA THIS MRNG TO PUSH OUT INTO LK SUP. WITH
ABUNDANT SUNSHINE OVER THE CENTRAL AND E ALONG WITH H85 TEMPS NEAR
17C...EXPECT HI TEMPS TO RISE WELL INTO THE 80S AGAIN AWAY FM THE
MODERATING INFLUENCE OF MAINLY LK MI IN LLVL SSW FLOW. BUT RATHER
WEAK PRES GRADIENT FCST THIS AFTN WL ALLOW FOR LK BREEZE FORMATION
OFF LK SUP AS WELL.
TONIGHT...MODELS IN GOOD AGREEMENT SHOWING AXIS OF HIER H7 MSTR
REMAINING OVER NW LK SUP OVERNGT ON THE NW FLANK OF NEARLY STNRY UPR
RDG CENTERED OVER THE LOWER GRT LKS. ANOTHER SHRTWV IS FCST TO RIDE
NEWD THRU MN LATE TNGT IN THE WSW FLOW ALF ARND THE RDG...BUT BULK
OF MODELS INDICATE ANY ASSOCIATED PCPN WL REMAIN OVER THE LK WITH
MID LVL CAPPING OVER THE LAND CWA CLOSER TO THE HIER HGTS DESPITE
ARRIVAL OF MORE HUMID LLVL AIR THAT WL ALLOW FOR SOME FOG FORMATION
AT LEAST OVER THE W HALF.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM EDT SUN JUL 14 2013
UPPER LEVEL HIGH CENTERED OVER MID ATLANTIC EXPANDS WESTWARD ACROSS
THE OHIO VALLEY AND MISSISSIPPI RIVER VALLEY INTO WEDNESDAY. LATER
WEDNESDAY THROUGH THURSDAY NORTHERN STREAM TROUGH/MID-LEVEL SPEED
MAX SMASHES THE RIDGE SOUTH OF UPPER GREAT LAKES. APPEARS THAT
NORTHERN STREAM TROUGH WILL BE STRONG ENOUGH TO PUSH SFC-H85 FRONT
ACROSS UPR MICHIGAN WED AFTN THROUGH THURSDAY. TROUBLE IS THAT FRONT
WILL NOT MOVE TOO FAR SOUTH AS IT BECOMES PARALLEL TO UPPER FLOW.
WITH FRONT CLOSE BY AND SINCE UPPER LAKES WILL BE ON NORTHERLY EDGE
OF HIGHER INSTABILITY GRADIENT AND ON SOUTHERN EDGE OF STRONGER
WINDS ALOFT...WILL HAVE CHANCE POPS WEDNESDAY THROUGH THURSDAY
NIGHT. AT THIS POINT...BEST CHANCES OF WIDESPREAD SHRA/TSRA WOULD BE
WEDNESDAY THEN AGAIN THURSDAY AFTN/EVENING. BY LATER FRIDAY AND INTO
NEXT WEEKEND...HEIGHTS FROM THE NORTH LOWER ENOUGH TO PUSH FRONT FAR
ENOUGH SOUTH TO SHOW A DRYING TREND.
HIGH PRESSURE BUILDING ALOFT ON MONDAY WHILE WEAK HIGH PRESSURE IS
OVER THE AREA AT THE SFC. COULD BE LOCALIZED LAKE BREEZES OFF LK
SUPERIOR NCNTRL AND ON KEWEENAW. PATTERN FAVORS MOST LAKE COOLING
OFF LK MICHIGAN THOUGH. WEAK CONVERGENCE ALONG LK BREEZES BUT
MLCAPES ARE MEAGER WITH SUBSIDENCE FROM BUILDING RIDGE ALOFT.
CU MAY BE ENHANCED OVR CNTRL CWA BUT WILL NOT INCLUDE ANY POPS
DUE TO MINIMAL INSTABILITY. SFC RIDGE AXIS MOVES EAST BY TUESDAY
WHILE SFC TROUGH CROSSES NORTHERN MANITOBA AND NORTHWEST ONTARIO.
GRADIENT SSW WIND SHOULD LIMIT LAKE SUPERIOR BREEZE. H85 TEMPS SURGE
TO +18C...SO EXPECT TEMPS INTO THE UPPER 80S AWAY FM LK MICHIGAN.
HIGHER DWPNT/INSTABILITY THAN MONDAY WITH MLCAPES OVER 1000
J/KG...BUT OVERALL THE LOW-LEVEL CONVERGENCE IS MINIMAL. COULD
SEE ISOLD-SCT SHRA/TSRA FORM OVER CNTRL CWA NEAREST LK MICHIGAN LAKE
BREEZE. WITH DEEP LAYER SHEAR OVER 30 KTS...CANNOT RULE OUT AN ISOLD
SVR STORM.
GENESIS REGION FOR MORE ORGANIZED SHRA/TSRA ON TUESDAY EVENING MAY
BE IN THE VCNTY OF UPPER LAKES INTO NORTHERN PLAINS CLOSER TO TAIL
END OF SFC TROUGH EXTENDING SOUTHWEST OF SFC LOW CROSSING NORTHERN
ONTARIO. MAX MOISTURE ADVECTION/LOW-LEVEL JET WOULD BE OVER NW
PORTION OF UPPER LAKES. MEAN STORM MOTION/FORWARD PROPAGATING
CORFIDI VECTORS AND 850-300MB THICKNESS SUGGEST THAT IF SHRA/TSRA
FORM IN THE EVENING THEY WOULD TRACK ACROSS UPR MICHIGAN TUE NIGHT.
WILL GO WITH LOW CHANCES ON TUESDAY NIGHT ACROSS WESTERN CWA. IDEA
MATCHES SPC SREF 3 HR PROBABILITY FOR TSRA. IF ORGANIZED CONVECTION
MATERIALIZES...WOULD AGAIN BE SOME RISK OF SVR MAINLY IN THE FORM OF
STRONG WIND GUSTS.
SFC FRONT AND DWPNTS POOLING TO NEAR 70 DEGREES IN AREA ON
WEDNESDAY. DEPENDING HOW OVERNIGHT CONVECTION GOES THERE MAY BE AN
INITIAL ROUND OF SHRA/TSRA OVER THE AREA ON WEDNESDAY MORNING WITH
ANOTHER INCREASE DURING THE AFTN. MLCAPES PUSHING 1500J/KG WITH DEEP
LAYER SHEAR 30-40 KTS INDICATES THIS COULD BE YET ANOTHER SVR
WEATHER DAY. SYNOPTIC PATTERN POINTS TO WIND/BOW ECHO TYPE OF
SITUATION. MUCH TOO EARLY TO GET CAUGHT UP IN THESE DETAILS YET
THOUGH. SOME INDICATIONS THAT FRONT MAY BE THROUGH NORTHERN TIER OF
CWA WITH MAIN FOCUS FOR AFTN CONVECTION OVER THE SCNTRL IN AREA OF
STRONGER SFC-H85 CONVERGENCE. CONSENSUS POPS HAVE THE HIGHER POPS
SCNTRL WITH LESSER POPS NEAR LK SUPERIOR. TEMPS COULD SHOW A PRETTY
SHARP RANGE ON WEDNESDAY...ESPECIALLY IF ONSHORE NORTH WINDS DEVELOP
IN THE NORTH CWA EARLIER IN THE DAY. MIXING TO H85 TEMPS STILL NEAR
+17C YIELDS HIGHS INTO THE UPPER 80S SCNTRL. 70S TO NEAR 80 DEGREES
WILL BE THE CASE NEAR LK SUPERIOR. OVERALL A LULL EXPECTED LATER
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. BY THURSDAY AFTN...SFC-H85
WINDS BACKING MORE SW AHEAD OF ANOTHER SHORTWAVE/H5 SPEED MAX
DIGGING INTO NORTHERN PLAINS. H85 WARM AIR ADVECTION ALONG WITH
MOISTURE TRANSPORT AND FACT THAT UPR MICHIGAN IS FCST TO BE ALONG
NORTH EDGE OF MUCAPE GRADIENT SUGGESTS ANOTHER ROUND OF SHRA/TSRA
OVER PARTS OF THE AREA THURSDAY AFTN/THURSDAY NIGHT. MAY EVEN SEE
ANOTHER CONVECTIVE WIND TYPE OF SITUATION.
CONSENSUS POPS SHOW THE DRYING TREND KICKING IN ON FRIDAY FM NORTH
TO SOUTH AS MAIN SFC COLD FRONT PLOWS INTO THE REGION. EXPECT DRY
WEATHER AND COOLER TEMPERATURES TO BE MAIN WEATHER STORY BY TIME
NEXT WEEKEND ARRIVES. ONSHORE GRADIENT NORTH WINDS LIKELY WILL KEEP
TEMPS IN THE 60S ALONG LK SUPERIOR FRIDAY AND SATURDAY. MAY ALSO SEE
INCREASED SWIM RISK AT THAT TIME AS WELL. IN THE MEANTIME...A WARM
AND HUMID SUMMERTIME REGIME WILL BE IN PLACE THROUGH MUCH OF THE
UPCOMING WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 124 AM EDT SUN JUL 14 2013
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST. ONLY CONCERN IS
THE SLIGHT POSSIBILITY OF CONVECTION IMPACTING FORECAST SITES OF
KCMX AND KIWD. THUNDERSTORMS OVER THE NORTHERN PLAINS ASSOCIATED
WITH A SHORT WAVE CONTINUE TO WORK EAST OVERNIGHT WHILE HIGH
PRESSURE BUILDS IN FROM THE EAST. THERE IS A CONCERN THAT THE
APPROACHING SHORT WAVE MAY INITIATE CONVECTION ALONG A TROUGH
EXTENDING ACROSS MN...FROM SW TO NE. BEST CONVERGENCE TO REMAIN
ALONG THIS BOUNDARY...AS LONG AS THE TROUGH DOES NOT PUSH TOO FAR
EAST BOTH THE WESTERN TAF SITES WILL STAY DRY OVERNIGHT AND INTO THE
EARLY DAYLIGHT HOURS EXCEPT FOR A FEW SPRINKLES UNDER AN AXIS OF
HIER MOISTURE CURRENTLY OVER WESTERN UPPER MI. BY LATE
MORNING...HIGH PRESSURE BECOMES DOMINANT WITH DRY AND STABLE
CONDITIONS PREVAILING THROUGH THE REMAINDER OF THE FORECAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EDT SUN JUL 14 2013
WITH HIGH PRESSURE NUDGING INTO THE UPPER GREAT LAKES AND A WEAK LOW
PRESSURE TROUGH TO THE WEST...WINDS WILL GENERALLY REMAIN LESS THAN
15-20 KNOTS THROUGH THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...RJT/KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1148 PM MDT SAT JUL 13 2013
.AVIATION...
06Z TAF CYCLE
A FEW SHOWERS AND THUNDERSTORMS TO IMPACT KABQ AND KSAF THROUGH 08Z.
BUT VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. ANOTHER ROUND
OF SHOWERS AND STORMS SUNDAY AFTERNOON WITH MAIN FOCUS ON THE
NORTHERN MOUNTAINS AND NORTHEAST AS A STRONG BACK DOOR COLD FRONT
MOVES INTO THESE AREAS. BRIEF MVFR TO IFR CONDITIONS FROM THE
STRONGER THUNDERSTORMS. STRONG EAST CANYON WINDS LIKELY SUNDAY
NIGHT INTO THE RIO GRANDE VALLEY WITH GUSTS AROUND 40 KTS. STRONG
MOISTURE PUSH INTO THE EAST AS WELL SUNDAY NIGHT. CHJ
&&
.PREV DISCUSSION...1039 PM MDT SAT JUL 13 2013...
QUICK UPDATE TO TWEAK POPS TO REFLECT CURRENT TRENDS. LOOKS LIKE
MUCH OF THE ACTIVITY FOR THE REMAINDER OF THE EVENING WILL BE OVER
OR NEAR THE RIO GRANDE VALLEY. THE HRRR CORROBORATES THIS WELL.
OTHERWISE...MADE SOME MINOR TWEAKS TO QPF AND SKY. UPDATES ALREADY
OUT. 34
.PREV DISCUSSION...322 PM MDT SAT JUL 13 2013...
STARTING BACK ON SHIFT AFTER WEEK AND A HALF ABSENCE...SO HAVE
BEEN DIGESTING THE RATHER BIZARRE PATTERN SHIFT UPCOMING. DECENT
CROP OF SCATTERED SHOWERS AND STORMS GOING THIS AFTN...BUT THE
SACRAMENTOS HAVE OPTED OUT SO FAR. SO ONCE AGAIN THE WEST IS BEST
AND EAST IS LEAST WITH REGARDS TO CONVECTION AND TREND SHOULD
CONTINUE INTO THE EVE. SHOULD FOR THE MOST PART SEE THE ACTIVITY
DIMINISHING LATER ON THIS EVE AND OVERNIGHT...BUT AS WITH LAST
NIGHT A FEW LOCALES IN THE CENTRAL...WEST AND NORTH MAY FIRE UP
WITH ISOLATED CELLS LATE TONIGHT...MORE LIKELY THOSE THAT HAD
LITTLE ACTION DURING THE DAY OR EARLY EVE AND HAVE SOME LEFTOVER
BOUNDARY INTERACTIONS.
NOW ONTO THE CHANGES THAT THIS FCSTR HAS NOT SEEN...AT LEAST NOT
TO ANYWHERE NEAR THIS DEGREE...SINCE GETTING HERE NEARLY 20 YEARS
AGO. NAMELY THE FAIRLY RAPID WESTWARD PROGRESSION OF A NON-
TROPICAL WELL DEVELOPED MID AND UPPER LVL LOW NOW OVER THE WESTERN
OHIO VALLEY. IT IS FAIRLY INACTIVE IN TERMS OF PCPN CURRENTLY...
BUT THERE IS A DISTURBANCE AND SLUG OF MOISTURE TO ITS NW AND
PRETTY DECENT LOW LVL MOISTURE WHICH WILL BE DRAWN UP ON ITS EAST
SIDE...ESPECIALLY AS IT REACHES THE OK N TX REGION LATER SUN.
MODELS PRETTY CONSISTENT STILL PINWHEELING THAT DISTURBANCE...AND
MOISTURE...INTO AND ACROSS NM FROM NE TO SW LATER SUN INTO MON.
BUT ALSO IT WILL DRAW TERRAIN INDUCED CONVECTION SOUTHWARD FROM
THE HIGHER MTNS OF CO INTO THE STATE AS WELL AS UPSLOPE INDUCED
RAINS FROM E CO AND NE NM SOUTHWARD ACROSS THE AREA. SO WHILE
THERE WILL BE QUITE A LOT OF CLOUD COVER TO DEAL WITH...THE ADDED
UPPER LEVEL DYNAMICS...AFOREMENTIONED UPSLOPE AND OVERALL
SIGNIFICANT MOISTURE INCREASE THOUGHT THE ATMOSPHERIC COLUMN
SHOULD ACT TO KEEP AT LEAST SOME CONVECTION GOING ALONG WITH AREAS
OR MORE STRATIFORM RAINS. WILL BE LOOKING AT A LIKELY UPSWING IN
FLASH FLOOD POTENTIAL LATE SUN INTO AT LEAST TUE FOR CENTRAL MTN
CHAIN EAST AT LEAST TO THE ADJACENT HIGHLANDS AND HIGH PLAINS TO
THE EAST...DUE LARGELY TO UPSLOPE EFFECTS AND MIX OF CONVECTIVE
AND STRATIFORM PCPN...THEN AT LEAST MON AND TUE FROM THE DIVIDE
PERHAPS AS FAR EAST AS WEST EDGE OF RIO GRANDE VALLEY. SOME
MODERATE TO PERHAPS STRONG EAST WINDS INTO RIO GRANDE VALLEY
ITSELF MAY HAVE SOME NEGATIVE IMPACTS ON RAINFALL AMTS IN PORTIONS
OF THE VALLEY...BUT ALL IN ALL THIS SYSTEM SHOULD REALLY DO A LOT
FOR WATERING THE GAPS IN PCPN COVERAGE SO FAR SEEN SINCE THE ONSET
OF THE RECENT SCATTERED RAINFALL. WILL BE LOOKING AT A POSS FLASH
FLOOD WATCH ISSUANCE IN NEXT 1 TO 3 SHIFTS...BUT FOR NOW WILL GO
WITH A SPECIAL WX STATEMENT ADDRESSING THIS POTENTIAL. 43
&&
.FIRE WEATHER...
WET WEATHER PATTERN TO ENSUE BEGINNING SUNDAY EVENING THROUGH AT
LEAST THE MIDDLE OF NEXT WEEK. AS A RESULT...NO FIRE WEATHER
CONCERNS THROUGH THE MIDDLE OF NEXT WEEK...THE COMBINATION OF
CONTINUED MONSOONAL MOISTURE FLOW INTO THE REGION AND A WESTWARD
MOVING UPPER LOW. TEMPERATURES WILL BE BELOW SIGNIFICANTLY NORMAL
MONDAY TO THURSDAY WITH MORE WIDESPREAD STORMS...WETTING RAINS AND
CLOUDINESS.
RH RECOVERIES WILL GOOD TOMORROW THEN EXCELLENT MONDAY THROUGH
THURSDAY. FRIDAY AND SATURDAY RH RECOVERIES WILL BE GOOD AS AIRMASS
DRYING IS EXPECT AS THE UPPER LOW RETREATS SOUTH INTO NORTHERN
MEXICO. WIND CONCERNS MOSTLY WITH THUNDERSTORM OUTFLOWS DURING THE
PERIOD EXCEPT FOR AN EASTERLY GAP/CANYON WINDS THAT WILL DEVELOP
SUNDAY NIGHT THROUGH MONDAY MORNING AND LIKELY AGAIN MONDAY NIGHT TO
EARLY TUESDAY. THESE GUSTY WINDS WILL BE STRONGEST DOWNWIND OF
CENTRAL GAPS/CANYONS AS SYNOPTIC EASTERLY FLOW DEVELOPS BENEATH THE
APPROACHING UPPER LOW. LOWER MIXING HEIGHTS EXPECTED WITH THIS
COOLER/MOIST AIRMASS. NO WIDESPREAD VENTILATION ISSUES EXPECTED FOR
THE UPCOMING WEEK. 01
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
40
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1039 PM MDT SAT JUL 13 2013
.UPDATE...
QUICK UPDATE TO TWEAK POPS TO REFLECT CURRENT TRENDS. LOOKS LIKE
MUCH OF THE ACTIVITY FOR THE REMAINDER OF THE EVENING WILL BE OVER
OR NEAR THE RIO GRANDE VALLEY. THE HRRR CORROBORATES THIS WELL.
OTHERWISE...MADE SOME MINOR TWEAKS TO QPF AND SKY. UPDATES ALREADY
OUT. 34
&&
.PREV DISCUSSION...657 PM MDT SAT JUL 13 2013...
.AVIATION...
00Z TAF CYCLE
EVENING SHOWERS AND THUNDERSTORMS TO MAINLY IMPACT KGUP WHILE
HOLDING ONTO VCTS AT KFMN...KSAF AND KABQ THROUGH 02Z OR 03Z.
VCSH THROUGH ABOUT 06Z AT ABOVE LISTED TAFS. BRIEF MVFR VISIBILITY
FROM ANY THUNDERSTORM THIS EVENING...OTHERWISE VFR CONDITIONS
THROUGH 18Z SUNDAY. ANOTHER ROUND OF SHOWERS AND STORMS SUNDAY
AFTERNOON WITH MAIN FOCUS ON THE NORTHERN MOUNTAINS AND NORTHEAST
AS A STRONG BACK DOOR COLD FRONT MOVES INTO THESE AREAS. CHJ
.PREV DISCUSSION...322 PM MDT SAT JUL 13 2013...
STARTING BACK ON SHIFT AFTER WEEK AND A HALF ABSENCE...SO HAVE
BEEN DIGESTING THE RATHER BIZARRE PATTERN SHIFT UPCOMING. DECENT
CROP OF SCATTERED SHOWERS AND STORMS GOING THIS AFTN...BUT THE
SACRAMENTOS HAVE OPTED OUT SO FAR. SO ONCE AGAIN THE WEST IS BEST
AND EAST IS LEAST WITH REGARDS TO CONVECTION AND TREND SHOULD
CONTINUE INTO THE EVE. SHOULD FOR THE MOST PART SEE THE ACTIVITY
DIMINISHING LATER ON THIS EVE AND OVERNIGHT...BUT AS WITH LAST
NIGHT A FEW LOCALES IN THE CENTRAL...WEST AND NORTH MAY FIRE UP
WITH ISOLATED CELLS LATE TONIGHT...MORE LIKELY THOSE THAT HAD
LITTLE ACTION DURING THE DAY OR EARLY EVE AND HAVE SOME LEFTOVER
BOUNDARY INTERACTIONS.
NOW ONTO THE CHANGES THAT THIS FCSTR HAS NOT SEEN...AT LEAST NOT
TO ANYWHERE NEAR THIS DEGREE...SINCE GETTING HERE NEARLY 20 YEARS
AGO. NAMELY THE FAIRLY RAPID WESTWARD PROGRESSION OF A NON-
TROPICAL WELL DEVELOPED MID AND UPPER LVL LOW NOW OVER THE WESTERN
OHIO VALLEY. IT IS FAIRLY INACTIVE IN TERMS OF PCPN CURRENTLY...
BUT THERE IS A DISTURBANCE AND SLUG OF MOISTURE TO ITS NW AND
PRETTY DECENT LOW LVL MOISTURE WHICH WILL BE DRAWN UP ON ITS EAST
SIDE...ESPECIALLY AS IT REACHES THE OK N TX REGION LATER SUN.
MODELS PRETTY CONSISTENT STILL PINWHEELING THAT DISTURBANCE...AND
MOISTURE...INTO AND ACROSS NM FROM NE TO SW LATER SUN INTO MON.
BUT ALSO IT WILL DRAW TERRAIN INDUCED CONVECTION SOUTHWARD FROM
THE HIGHER MTNS OF CO INTO THE STATE AS WELL AS UPSLOPE INDUCED
RAINS FROM E CO AND NE NM SOUTHWARD ACROSS THE AREA. SO WHILE
THERE WILL BE QUITE A LOT OF CLOUD COVER TO DEAL WITH...THE ADDED
UPPER LEVEL DYNAMICS...AFOREMENTIONED UPSLOPE AND OVERALL
SIGNIFICANT MOISTURE INCREASE THOUGHT THE ATMOSPHERIC COLUMN
SHOULD ACT TO KEEP AT LEAST SOME CONVECTION GOING ALONG WITH AREAS
OR MORE STRATIFORM RAINS. WILL BE LOOKING AT A LIKELY UPSWING IN
FLASH FLOOD POTENTIAL LATE SUN INTO AT LEAST TUE FOR CENTRAL MTN
CHAIN EAST AT LEAST TO THE ADJACENT HIGHLANDS AND HIGH PLAINS TO
THE EAST...DUE LARGELY TO UPSLOPE EFFECTS AND MIX OF CONVECTIVE
AND STRATIFORM PCPN...THEN AT LEAST MON AND TUE FROM THE DIVIDE
PERHAPS AS FAR EAST AS WEST EDGE OF RIO GRANDE VALLEY. SOME
MODERATE TO PERHAPS STRONG EAST WINDS INTO RIO GRANDE VALLEY
ITSELF MAY HAVE SOME NEGATIVE IMPACTS ON RAINFALL AMTS IN PORTIONS
OF THE VALLEY...BUT ALL IN ALL THIS SYSTEM SHOULD REALLY DO A LOT
FOR WATERING THE GAPS IN PCPN COVERAGE SO FAR SEEN SINCE THE ONSET
OF THE RECENT SCATTERED RAINFALL. WILL BE LOOKING AT A POSS FLASH
FLOOD WATCH ISSUANCE IN NEXT 1 TO 3 SHIFTS...BUT FOR NOW WILL GO
WITH A SPECIAL WX STATEMENT ADDRESSING THIS POTENTIAL.
43
.FIRE WEATHER...
WET WEATHER PATTERN TO ENSUE BEGINNING SUNDAY EVENING THROUGH AT
LEAST THE MIDDLE OF NEXT WEEK. AS A RESULT...NO FIRE WEATHER
CONCERNS THROUGH THE MIDDLE OF NEXT WEEK...THE COMBINATION OF
CONTINUED MONSOONAL MOISTURE FLOW INTO THE REGION AND A WESTWARD
MOVING UPPER LOW. TEMPERATURES WILL BE BELOW SIGNIFICANTLY NORMAL
MONDAY TO THURSDAY WITH MORE WIDESPREAD STORMS...WETTING RAINS AND
CLOUDINESS.
RH RECOVERIES WILL GOOD TOMORROW THEN EXCELLENT MONDAY THROUGH
THURSDAY. FRIDAY AND SATURDAY RH RECOVERIES WILL BE GOOD AS AIRMASS
DRYING IS EXPECT AS THE UPPER LOW RETREATS SOUTH INTO NORTHERN
MEXICO. WIND CONCERNS MOSTLY WITH THUNDERSTORM OUTFLOWS DURING THE
PERIOD EXCEPT FOR AN EASTERLY GAP/CANYON WINDS THAT WILL DEVELOP
SUNDAY NIGHT THROUGH MONDAY MORNING AND LIKELY AGAIN MONDAY NIGHT TO
EARLY TUESDAY. THESE GUSTY WINDS WILL BE STRONGEST DOWNWIND OF
CENTRAL GAPS/CANYONS AS SYNOPTIC EASTERLY FLOW DEVELOPS BENEATH THE
APPROACHING UPPER LOW. LOWER MIXING HEIGHTS EXPECTED WITH THIS
COOLER/MOIST AIRMASS. NO WIDESPREAD VENTILATION ISSUES EXPECTED FOR
THE UPCOMING WEEK. 01
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
543 AM EDT SUN JUL 14 2013
.SYNOPSIS...
A LARGE HIGH PRESSURE SYSTEM AT THE SURFACE AND ALOFT OVER
PENNSYLVANIA WILL TRACK SLOWLY WESTWARD INTO THE OHIO VALLEY THIS
WEEK. A COLD FRONT WILL LIKELY PUSH SOUTHWARD THRU THE REGION BY
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK INVERTED SFC TROF AND ASSOC PLUME OF ANOMALOUS PWATS LIFTING
NORTHWARD INTO CENTRAL PA EARLY THIS AM. RADAR LOOP AT 09Z SHOWS
JUST A FEW LIGHT SHOWERS/SPRINKLES ALONG THIS BOUNDARY WEST OF
HARRISBURG. RAP OUTPUT SHOWS THIS BAND OF HIGHER PWATS LIFTING TO
THE N TIER COUNTIES BY LATE AM. HOWEVER...GIVEN CURRENT RADAR
COVERAGE AND LACK OF LG SCALE FORCING...WILL NOT EXPLICITLY
MENTION PRECIP IN THE FCST THIS MORNING.
PLENTY OF LOW LVL MOISTURE AND A LINGERING LIGHT SE FLOW IS
PROMOTING INCREASING LOW CLOUDS/FOG EARLY THIS AM...AS EVIDENCED
BY 11-3.9U SATL LOOP. HOWEVER...AS SFC HIGH PRES SLIDES SOUTHWARD
OFF THE E COAST...FLOW ACROSS PA WILL SHIFT FROM SE TO SOUTH...BRINGING
BRIGHTER AND WARMER CONDS BY AFTN. ENS MEAN 925 TEMPS SUPPORT HIGH
TEMPS BTWN 85-90F.
LINGERING INVERTED SFC TROUGH AND ASSOC BAND OF ANOMALOUS PWATS
WILL LIE ALONG THE NY/PA BORDER THIS AFTN. DIURNAL HEATING OF THIS
MOIST...UNSTABLE AIR MASS COULD PRODUCE ISOLATED AFTN TSRA ACROSS
THE N MTNS LATE IN THE DAY. WEAK SHEAR INDICATES ANY STORMS THAT
FORM WILL BE OF THE PULSE VARIETY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
ANY ISOLD...DIURNALLY-DRIVEN EVENING TSRA ACROSS THE NORTH SHOULD DIE
OUT ARND SUNSET. WARM AND MUGGY CONDS EXPECTED THE REST OF THE NIGHT
WITH TEMPS RANGING FROM THE M60S OVR THE ALLEGHENIES...TO ARND 70F
IN THE SUSQ VALLEY.
DESPITE PRESENCE OF ANOMALOUS 5H HIGH PRES OVR PA...DIURNAL
HEATING OF MOIST AIR MASS SHOULD BE SUFFICIENT TO BREAK CAP AT
ARND 650MB...PRODUCING A FEW TSRA MONDAY AFTN. LINGERING SFC TROF AND
ASSOC BAND OF ANOMALOUS PWATS IS FCST TO LIE ACROSS CENTRAL
PA...RESULTING IN THE SCT PM CONVECTION ACROSS CENTRAL PA. GEFS
MEAN 8H TEMPS ARND 19C SHOULD TRANSLATE TO HIGH TEMPS FROM THE
U80S ACROSS THE ALLEGHENY PLATEAU...TO THE M90S IN THE SUSQ
VALLEY. THE COMBINATION OF HEAT AND HUMIDITY SHOULD PUSH HEAT
INDICES TO NR 100F ACROSS THE SUSQ VALLEY. WILL LET LATER SHIFTS
DECIDE WHETHER TO PULL THE TRIGGER ON A HEAT ADVISORY WITH BENEFIT
OF LATER GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH CONFIDENCE HEAT WAVE FOR CENTRAL PA MUCH OF NEXT WEEK...AS
ALL MED RANGE GUIDANCE SHOWING ANOMALOUS MID LVL HIGH PRESSURE
CENTER PARKED OVR THE OHIO VALLEY/MIDWEST WITH ANOMALOUS 8H TEMPS
OF NR 20C ACROSS PA.
THE DEVELOPING..DEEP LAYER NWRLY FLOW WOULD ORDINARILY BE QUITE
FAVORABLE FOR CONVECTION /EVEN A FEW MCS TYPE SYSTEMS/ MOVING
QUICKLY SE FROM THE UPPER GLAKES REGION AND INTO OUR AREA.
HOWEVER...IT APPEARS THAT EVEN THOUGH WE HAVE TREMENDOUS LLVL
MOISTURE...HEAT /WITH TEMPS IN THE L-MID 90S THROUGHOUT THE
VALLEYS/...AND ASSOCIATED PERIODS OF HIGH ML CAPE OF 2000-3000
J/KG...A STRONG MID LEVEL CAP /WITH 700 MB TEMPS AVERAGING 10-11C/
WILL PREVENT MUCH MORE THAN ISOLATED AND GENERALLY OROGRAPHICALLY
INDUCED MID TO LATE AFTERNOON SHOWERS AND THUNDERSTORMS FOR TUESDAY
THROUGH THURSDAY. PRACTICALLY ALL OF THE /ISOLATED/ CONVECTION
WILL BE IN THE 19-00Z TIMEFRAME EACH AFTERNOON/EVENING.
WILL STILL HAVE TO KEEP A CLOSE EYE JUST TO OUR NORTH AND NE FOR
THE POSSIBILITY OF SOME WEAKNESSES IN THIS CAP FROM A FEW WEAK
SHORT WAVES THAT MAY DROP TO DROP SE FROM NEW YORK STATE AND NIP
AWAY AT THE WWD MOVING UPPER HIGH AND MID LEVEL CAP.
ENOUGH LLVL CONVERGENCE AND INCREASED LG SCALE...DEEP LAYER UVVEL
MAY DEVELOP FRIDAY AFTERNOON /ALONG THE NRN EDGE OF THE
AFOREMENTIONED MID LEVEL CAP/ TO DEVELOP ONE OR MORE CLUSTERS OF
STRONG TO POTENTIALLY SEVERE TSRA JUST AHEAD OF A SFC CFRONT THAT
WILL EXTEND FROM THE WRN GLAKES...TO NEAR THE NORTH SHORE OF LAKE
ONTARIO BY 00Z SATURDAY. NRN PARTS OF THE CWA STAND THE GREATEST
CHC AT SEEING A TSRA LATE FRIDAY.
ALTHOUGH THE CURRENT MDL 8H TEMPS DON/T SUPPORT RECORD HIGHS...PERHAPS
THE MOST IMPORTANT ASPECT TO THIS UPCOMING HEAT WAVE WILL BE IT/S
DURATION...LASTING MONDAY THRU AT LEAST FRIDAY. DAILY HEAT INDICES
SHOULD TOP OUR NR 100F EACH DAY ACROSS THE SUSQ VALLEY...ALONG
WITH NIGHTTIME LOWS IN THE L70S.
BY NEXT WEEKEND...GEFS AND EC ENSEMBLE OUTPUT INDICATE A SFC
CFRONT WILL SAG SOUTH /WITH UPPER HEIGHTS LOWERING ACROSS THE
GLAKES AND NE REGION...AS A SERIES OF FAST MOVING...AND QUITE
POTENT SHORTWAVES RIDE THROUGH THE RIGHT ENTRANCE REGION OF THE
LARGER SCALE 110 KT 300 MB JET /SITUATED FROM LAKE SUPERIOR TO SRN
QUEBEC/. THIS SETUP WILL AFFORD THE CHC FOR A FEW ROUND OF STRONG
TO POTENTIALLY SVR TSRA /AND ONE OR MORE MCS FEATURES/.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
A LARGE HIGH PRESSURE SYSTEM AT THE SURFACE AND ALOFT WILL BUILD
WESTWARD FROM THE ATLANTIC OCEAN AND PARK ITSELF OVER THE OHIO
VALLEY...BRINGING A PERIOD OF EXCELLENT FLYING CONDITIONS.
HOWEVER...BEFORE THAT WE/LL SEE LIGHT FOG AND AN IFR/MVFR STRATOCU
DECK DEVELOP IN SOUTHERLY FLOW OVER CENTRAL PA OVERNIGHT /AFTER
08Z/ AS LOW LEVEL MOISTURE REMAINS TRAPPED UNDER BUILDING
SUBSIDENCE INVERSION. WEAK SHOWERS DRIFTING NORTHWARD FROM
MARYLAND WILL CONTINUE TO FALL APART AS THEY APPROACH THE MASON
DIXON LINE.
LOW CIGS SHOULD CONTINUE UNTIL 14-15Z...WHEN BOUNDARY LAYER SHOULD
MIX OUT AND BRING VFR CONDITIONS FOR THE REMAINER OF THE DAY. THIS
WILL BE THE BEGINNING OF A SEVERAL DAY PERIOD WITH OVERALL
EXCELLENT FLYING CONDITIONS...WITH ONLY LOCALIZED MORNING FOG AND
CHANCES FOR AN AFTERNOON TSTM EACH DAY. TODAY THAT TSTM CHANCE
WILL BE ACROSS THE NORTHERN TIER IN VICINITY OF A WEAKENING TROUGH
JUST TO OUR NORTH AND IN THE LAURELS...BUT CHANCES TOO LOW TO
MENTION IN KBFD-KJST TAFS.
OUTLOOK...
MON-THU...MAINLY VFR. DAILY LOCAL RESTRICTIONS POSS IN LIGHT
MORNING FOG AND ISO AFT TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...DEVOIR/FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 AM CDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR TODAY IS ON TEMPERATURES AND CLOUD COVER AS
UPPER LEVEL RIDGING PUSHES IN FROM THE EAST.
CURRENTLY...SOME SCATTERED CONVECTION HAS DEVELOPED ALONG THE
DEFORMATION BAND OF A WEAK 500MB TROUGH THAT EXTENDS FROM
NORTHWEST WISCONSIN DOWN INTO WESTERN IOWA. EXTENSIVE MID TO UPPER
LEVEL CLOUD COVER COMES WITH THIS BAND AND HAS BEEN SLOW TO SHIFT
TO THE WEST THIS MORNING. THE 14.06Z RAP 700-400MB RH FIELDS SEEM
TO HAVE A GOOD HANDLE ON THIS CLOUD COVER AND DOES CONTINUE TO
SHIFT THIS CLOUD DECK AND CONVECTION TO THE WEST QUICKLY THIS
MORNING.
HIGH TEMPERATURES FOR TODAY ARE THE NEXT QUESTION AS MUCH OF THE
REGION SHOULD HAVE FULL SUN. 14.06Z RAP AND 14.00Z NAM/GFS
SOUNDINGS INDICATE THAT THE HIGHEST POSSIBLE MIXING WOULD COME
FROM AROUND 875-850MB. WHEN MIXING DOWN A PARCEL FROM THAT LEVEL
OR LOWER...IT SHOWS THAT HIGHS TODAY HAVE A MAX OUT IN THE MID TO
UPPER 80S. MAY SEE SOME FAIR WEATHER CU FORMING BUT THE LOW LEVEL
MOISTURE DOES NOT REALLY START RAMPING UP UNTIL MONDAY...SO THINK
THAT IT WILL BE FEW AND FAR BETWEEN FOR ANY OF THAT DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR THE UPCOMING WEEK IS WITH THE CHANCES FOR RAIN
ALONG WITH DAILY TEMPERATURES.
DESPITE A MAINLY SUBSIDENT ENVIRONMENT MONDAY THROUGH
WEDNESDAY...INCREASING LOW LEVEL MOISTURE WILL LEAD TO A MORE HUMID AIR
MASS THAT WILL HAVE THE POTENTIAL OF PRODUCING SOME VERY ISOLATED
SHOWERS AND THUNDERSTORMS. CONFIDENCE IS NOT VERY HIGH WITH
WHETHER THEY WILL EVEN DEVELOP BASED ON THE LACK OF A FORCING
MECHANISM...BUT GUIDANCE HAS BEEN CONSISTENT WITH SHOWING SOME
PRECIPITATION FORMING IN THE AFTERNOON DURING DIURNAL PEAK
HEATING. HAVE DECIDED TO HONOR THIS WITH SOME 20 PERCENT CHANCES
OF PRECIPITATION MONDAY/TUESDAY/WEDNESDAY AFTERNOON AS A RESULT.
ANY DEEP LAYER SHEAR IS NON-EXISTENT...SO THIS WILL BE
PULSEY/CELLULAR CONVECTION THAT IS BRIEF AND NON- SEVERE.
THE HIGHER CHANCES FOR PRECIPITATION WILL COME LATER IN THE WEEK
AS A COLD FRONT SAGS SOUTH FROM ALONG THE US/CANADIAN BORDER. THE
14.00Z GFS/ECMWF/GEM ALL ANGLE THIS FRONT FROM NEAR FARGO TO THE
EAST TOWARD NORTH CENTRAL WISCONSIN ON THURSDAY WITH CONVECTION
EXPECTED TO DEVELOP ALONG THIS REGION. THE FRONT IS THEN EXPECTED
TO GET A PUSH TO THE SOUTH FRIDAY INTO SATURDAY WITH THE GFS BEING
MUCH MORE WIDESPREAD ON ITS PRECIPITATION WHEN COMPARED TO THE
LATEST ECMWF RUN. HOWEVER...THE TIMING OF THIS FROPA STILL LOOKS
FAIRLY CONSISTENT BETWEEN THESE MODELS...SO HAVE SOME ABOVE
AVERAGE CONFIDENCE IN THE TIMING OF THE HIGHEST PROBABILITIES OF
PRECIPITATION BASED ON THIS FROPA.
LOW LEVEL TEMPERATURES APPEAR TO CLIMB GRADUALLY THROUGH THE WEEK
WITH 850MB TEMPERATURES JUMPING FROM AROUND +16C TODAY TO +20C BY
THURSDAY NIGHT AND 925MB TEMPERATURES GOING FROM +21C TODAY TO
+27C BY THURSDAY NIGHT. WITH MAINLY SUNNY SKIES...TEMPERATURES
SHOULD BE ABLE TO REACH 90F TUESDAY THROUGH THURSDAY AND PERHAPS
FRIDAY IF THE FRONT TAKES LONGER TO GET THROUGH.
&&
.AVIATION...THROUGH 06Z MONDAY
1124 PM CDT SAT JUL 13 2013
AREA REMAINS CAUGHT BETWEEN THE WESTERLIES TO OUR NORTH AND THE WESTWARD
MOVING SHORT WAVE TROUGH TRACKING INTO EASTERN MISSOURI. WITH NO UPPER
LEVEL STEERING FLOW...WE ARE CAUGHT WITH A NARROW BAND OF MID AND
HIGH LEVEL MOISTURE. THIS WILL LINGER THROUGH THE NIGHT...BUT THE
SOUTHERN WAVE WILL ADVECT SOME DRIER AIR IN FROM THE EAST SLOWLY
OVERNIGHT. WITH SOMEWHAT COOL TEMPERATURES AND DEW POINTS LINGERING
IN THE LOWER 60S...COULD SEE SOME LIGHT MIST FOR A FEW HOURS
AROUND SUNRISE. AS THE WAVE MAKES WESTWARD PROGRESS SUNDAY...HIGH
CLOUD SHOULD DIMINISH AND MOVE WEST. HOWEVER LOW LEVEL MOISTURE
WILL BE SLOWLY ON THE INCREASE...SO SOME CUMULUS DEVELOPMENT IS
POSSIBLE DIURNALLY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...MW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1055 AM EDT SUN JUL 14 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE REGION THROUGH THE MIDDLE OF THE
WEEK WITH A FEW TROUGHS OF LOW PRESSURE NEARBY. A COLD FRONT THEN
SLOWLY APPROACHES FROM THE NORTH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH WESTERLY WINDS INCREASING...THE FOG AND LOW CLOUDS CONTINUES
TO DISSIPATE.
MADE NO CHANGES TO TEMP FORECAST AS SKIES WILL BE PARTLY TO
MOSTLY SUNNY THIS AFTERNOON. ALONG WITH A WESTERLY WIND...MIXING
PROFILES SUPPORT HIGHS IN THE LOW 90S FOR PARTS OF NE NJ...AND
AROUND 90 FOR ADJACENT AREAS. UPPER 80S EXPECTED ELSEWHERE.
DEW POINTS ALOFT ARE ON THE HIGH SIDE...AND WILL COUNTERACT THE
SURFACE WESTERLY WINDS IN LOWERING SURFACE DEW POINTS. THINKING IS
THAT SURFACE DEW POINTS OUTSIDE OF SEA BREEZE INFLUENCES DROP ONLY
A COUPLE OF DEGREES FROM 12Z READINGS. THIS PRODUCES HEAT INDICES
MEETING HEAT ADVISORY CRITERIA NYC AND PARTS OF NE NJ. AS
SUCH...THE HEAT ADVISORY WILL REMAIN POSTED AS IS.
MID-LEVEL SHORTWAVE APPROACHES THIS AFTERNOON AS WELL. SOME
QUESTIONS AS TO WHERE IT WILL TRACK...BUT NAM AND HRRR INDICATING
CONVECTION A BIT FARTHER TO THE WEST...WILL INCREASE POPS TO
CHANCE ACROSS AREAS NORTH AND WEST OF THE CITY AND WILL KEEP
SLIGHT CHANCE POPS THROUGHOUT. WITH SFC DEW POINTS IN THE LOW 70S
AND PWATS APPROACHING 2 INCHES...WILL MENTION POTENTIAL FOR HEAVY
RAIN IN TSTMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
DRY WEATHER TONIGHT THROUGH TUESDAY NIGHT AS THE ATMOSPHERIC COLUMN
DRIES OUT.
ON MONDAY...850MB TEMPS RISE TO 18-19C...AND WITH A MOSTLY SUNNY
AFTERNOON...EXPECTING HIGHS IN THE LOWER AND MIDDLE 90S FOR MUCH OF
THE FORECAST AREA. WINDS IN THE MIXING LAYER...ALTHOUGH WITH AN
OFFSHORE COMPONENT...LOOK LIGHT ENOUGH TO ALLOW FOR SEA BREEZES TO
DEVELOP IN THE AFTERNOON...AND COMPLICATE THE SURFACE DEW POINT
FORECAST. DEW POINTS IN THE BOUNDARY LAYER ARE FORECAST TO BE LOW
ENOUGH TO ALLOW SURFACE DEW POINTS TO DROP AT LEAST 3-5 DEGREES FROM
12Z READINGS. BUT WITH AMBIENT TEMPERATURES IN THE MID 90S IN THE
CITY...WIDESPREAD HEAT INDEX VALUES OF 95-100 SHOULD BE REALIZED.
OUTSIDE OF THE CITY...100-104 DEGREE HEAT INDICES WILL BE WIDESPREAD
ACROSS PARTS OF NJ WHERE THE HEAT ADVISORY IS CURRENTLY IN EFFECT.
MIGHT NEED TO EVENTUALLY ADD ADJACENT ZONES TO THE ADVISORY...BUT AS
OF NOW...WIDESPREAD 100-104 INDICES ARE NOT FORECAST.
THERMAL TROUGH DEVELOPS IN THE AFTERNOON OVER WESTERN ZONES...AND
ANOTHER TROUGH APPROACHES FROM THE EAST. COMBINED WITH ANY LOCAL
SEA BREEZES...WILL GO AHEAD AND ADD ISOLATED POPS TO THE FORECAST
FOR THE AFTERNOON.
MODELS DIVERGE ON THE 850MB TEMPERATURE FORECAST FOR TUESDAY...BUT
BEST GUESS IS THAT THEY WILL BE THE SAME OR JUST SLIGHTLY LOWER THAN
ON MONDAY. EVEN IF THEY ARE LOWER...SURFACE HIGH TEMPERATURES WILL
PROBABLY BE VERY CLOSE TO THOSE OF MONDAY AS THE MIXED LAYER WILL BE
DRIER THIS TIME AROUND. THIS WILL ALSO SERVE TO ALLOW SURFACE
DEW POINTS TO MIX OUT MORE THAN ON MONDAY. THE RESULTING HEAT INDICES
WOULD STILL WARRANT A HEAT ADVISORY TO BE EXTENDED IN THE CITY...BUT
FALLING SHORT OF CRITERIA ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HEAT AND HUMIDITY CONTINUES THROUGH THE WEEK WITH ADDITIONAL HEAT
ADVSYS POSSIBLE...ESPECIALLY IN NYC. FORECASTING HEAT INDICES
BECOMES TROUBLESOME DUE TO THE POTENTIAL FOR THE MIXING DOWN OF
DRIER AIR FROM ALOFT EACH AFTERNOON. WILL NEED TO MONITOR TRENDS
CLOSELY IN THE COMING DAYS.
IN ADDITION TO THE HEAT...A TROUGH OF LOW PRES WILL BE NEAR OR OVER
THE AREA EACH DAY WITH THE POTENTIAL FOR DIURNALLY DRIVEN ISOLD
SHOWERS/TSTMS. PREDICTABILITY IS TOO LOW TO PINPOINT WHERE EXACTLY
THESE WILL OCCUR...HOWEVER ANY WEAK BOUNDARY OR CONVERGENCE ZONE
WILL BE CAPABLE OF TRIGGERING CONVECTION.
TOWARDS THE END OF THE FORECAST PERIOD A COLD FRONT WILL SLOWLY DROP
DOWN FROM THE N BRINGING THE POTENTIAL FOR MORE ORGANIZED PRECIP.
THE FRONT IS EXPECTED TO BECOME ALIGNED WITH THE FLOW ALOFT
RESULTING IN A SLOW PROGRESSION SOUTHWARD. THE DEGREE OF THIS VARIES
AMONGST THE MODEL GUIDANCE WHICH IS LEADING TO LARGE TIMING
DISCREPANCIES. HOWEVER...IT APPEARS THAT IT WILL COME THROUGH
SOMETIME NEXT WEEKEND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE OVER THE AREA WILL MOVE SLOWLY WEST THROUGH MONDAY.
WEAK TROUGHS OF LOW PRESSURE EXTENDING FROM SOUTHWEST TO NORTHEAST
JUST WEST OF THE LOCAL AREA WILL FORM SUNDAY AND MONDAY AFTERNOONS.
ISOLATED MVFR CIGS ARE POSSIBLE ACROSS THE LOCAL AREA UNTIL 16Z.
ISOLATED SHOWERS DEVELOPING OVER CT MIGHT EXPAND WEST ACROSS THE
HUDSON VALLEY AS THEY MOVE SLOWLY SOUTHEAST. FCST CONFIDENCE IS TOO
LOW TO INCLUDE IN THE TAF FORECASTS.
WINDS WILL BE WEST ARND 10 KT UNTIL 19Z WITH WEAK SEA BREEZES
DEVELOPING ACROSS THE COASTAL TERMINALS.
PATCHY MVFR FOG IS POSSIBLE AFT 06Z TONIGHT OUTSIDE OF THE NYC METRO
TERMINALS.
.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.MONDAY THROUGH THURSDAY...MAINLY VFR...BUT SUB-VFR CONDS POSSIBLE
IN SHRA/TSRA NORTH AND WEST OF NYC DURING THE AFTERNOON/EVENING
HOURS.
&&
.MARINE...
HIGH PRESSURE BUILDS OVER THE WATERS AND WILL REMAIN THROUGH THE
FORECAST PERIOD.
CONDITIONS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH THURSDAY. NO HAZARDS ARE EXPECTED OTHER THAN POSSIBLY FOR
FOG THROUGH THE REMAINDER OF THE PERIOD WITH A RELATIVELY WEAK FLOW
OVER THE WATERS.
&&
.HYDROLOGY...
A MOIST AIR MASS OVER THE AREA WILL RESULT IN THE POTENTIAL FOR
HEAVY DOWNPOURS ASSOCIATED WITH ANY TSTM ACTIVITY TODAY INTO THE
EVENING. PWATS AROUND 2 INCHES ASSOCIATED WITH ANY SLOW MOVING STORM
WILL HAVE THE CAPABILITY TO PRODUCE FLASH FLOODING...ALTHOUGH
CONFIDENCE IS LOW AT THIS TIME.
MONDAY AND TUESDAY LIKELY REMAIN DRY. THEREAFTER...STORMS ARE
EXPECTED TO BE ISOLD IN NATURE THROUGH AT LEAST THURSDAY...LIMITING
THE POTENTIAL FOR WIDESPREAD FLASH FLOODING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR NYZ072>075-
176-178.
NJ...HEAT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR NJZ006-104-
106-108.
MARINE...NONE.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC/MPS
SHORT TERM...JC/MPS
LONG TERM...
AVIATION...MET
MARINE...MET
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1007 AM CDT SUN JUL 14 2013
.DISCUSSION...
ISSUED 1007 AM CDT SUN JUL 14 2013
NO CHANGES ANTICIPATED TO THE CURRENT FORECAST. UPPER LOW THAT
BROUGHT WIDELY SCATTERED THUNDERSTORMS TO SOUTHERN ILLINOIS
YESTERDAY HAS NOW SHIFTED INTO EASTERN KANSAS. SOUTHEASTERLY FLOW
ON ITS BACKSIDE IS BRINGING INCREASING MOISTURE INTO THE REGION
THIS MORNING...AS EVIDENCED BY UPSTREAM 850MB DEWPOINTS OF 13C AT
BOTH KILN AND KOHX. DESPITE LACK OF GOOD UPPER-LEVEL
SUPPORT...INCREASING MOISTURE AND POSSIBLE WEAKNESS/TROUGH AXIS IN
PRESSURE FIELD MAY SUPPORT ISOLATED CONVECTION LATER THIS
AFTERNOON. 13Z HRRR SHOWS THIS OCCURRING ACROSS MAINLY THE E/SE
KILX CWA AFTER 21Z. WILL CONTINUE TO MENTION ISOLATED THUNDER IN
THE FORECAST ACCORDINGLY...ALTHOUGH THE MAJORITY OF THE AREA WILL
REMAIN WARM AND DRY TODAY.
BARNES
&&
.AVIATION...
ISSUED 605 AM CDT SUN JUL 14 2013
SOME MVFR VSBYS IN FOG FOR A COUPLE OF HOURS EARLY AND AGAIN LATE
IN THIS FORECAST PERIOD...OTHERWISE...VFR CONDITIONS ARE EXPECTED.
THE UPPER LEVEL DISTURBANCE THAT PRODUCED THE CONVECTION JUST SOUTH
OF OUR TAF SITES LATE YESTERDAY HAS SHIFTED OFF TO OUR SOUTHWEST
THIS MORNING. A MOIST SOUTHEAST FLOW WILL PREVAIL ACRS THE AREA
TODAY WHICH WILL RESULT IN THE DEVELOPMENT OF A CU FIELD LATER
THIS MORNING WITH BASES BETWEEN 4500-5000 FEET. IT STILL APPEARS
ANY CONVECTION THAT DEVELOPS LATER THIS AFTERNOON WILL BE TOO
ISOLATED IN COVERAGE TO MENTION IN TAFS. CONVECTION CHANCES WANE
JUST AFTER SUNSET WITH THE PSBLTY OF SOME PATCHY FOG FORMING
AGAIN AFTR 06Z. SFC WINDS TODAY WILL BE FROM AN EAST TO SOUTHEAST
DIRECTION AT AROUND 10 KTS...AND FROM 5 TO 10 KTS TONIGHT.
SMITH
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT SUN JUL 14 2013
SHORT TERM...TODAY THROUGH THURSDAY NIGHT
00Z MODELS ARE IN FAIR AGREEMENT THROUGH MID WEEK AS A HOT AND
HUMID WEEK IS AHEAD FOR CENTRAL AND SOUTHEAST IL. THIS DUE TO
STRONG 597 DM 500 MB HIGH PRESSURE RIDGE OFF THE SOUTHERN NEW
ENGLAND COAST INTO PA/NJ THAT RETROGRADES WESTWARD INTO THE OHIO
VALLEY AND SOUTHERN GREAT LAKES BY TUE AND STAYS NEAR IL AS IT
SLOWLY WEAKENS AND SHIFTS SOUTHWARD LATER THIS WEEK ALLOWING A
FRONTAL BOUNDARY TO SAG SOUTHWARD OVER THE REGION NEXT WEEKEND.
THIS BOUNDARY WILL BRING A BETTER CHANCE OF SHOWERS/THUNDERSTORMS
NEXT WEEKEND.
579 DM 500 MB LOW PRESSURE OVER SE MO MOVE QUICKLY WSW INTO
EASTERN OK BY SUNSET TODAY WHILE 597 DM 500 HIGH PRESSURE RIDGE
SHIFTS WESTWARD ACROSS PA AND INTO THE EASTERN GREAT LAKES REGION.
NOT MUCH LIFTING MECHISMS AROUND IL TODAY BUT INCREASING DEEPER
GULF MOISTURE CONTINUES TO STREAM NW INTO IL WITH PRECIPITABLE
WATER VALUES RISING TO 1.5 TO 2 INCHES THIS AFTERNOON AND HIGHEST
IN SE IL. AIRMASS GETS UNSTABLE THIS AFTERNOON WITH CAPES OF 1000
TO 2000 J/KG SE OF THE IL RIVER AND THIS SHOULD ALLOW ISOLATED
SHOWERS AND THUNDERSTORMS TO DEVELOP FROM MID AFTERNOON INTO EARLY
EVENING UNTIL SUNSET FROM I-72 SOUTH. SUNNY SKIES TO BECOME PARTLY
TO MOSTLY SUNNY IN AFTERNOON WITH HIGHS IN THE MID TO UPPER 80S.
DEWPOINTS IN THE LOW TO MID 60S TO RISE INTO THE UPPER 60S TO NEAR
70F BY AFTERNOON.
HAVE A SLIGHT CHANCE OF CONVECTION UNTIL MID EVENING FROM I-72
SOUTH THEN DRY REST OF TONIGHT WITH LOWS AROUND 70F. HAVE ISOLATED
CONVECTION DEVELOPING AGAIN DURING MONDAY AFTERNOON AND OVER IL
RIVER VALLEY TOO AS UNSTABLE AIRMASS SPREADS FURTHER NW. VERY WARM
AND HUMID WITH HIGHS IN THE UPPER 80S TO NEAR 90F MONDAY WITH
DEWPOINTS IN THE LOWER 70S. AFTERNOON HEAT INDICES IN MID TO UPPER
90S AND A FEW SPOTS IN SE IL BY WABASH RIVER NEARING 100F.
STRONG UPPER LEVEL RIDGE NEARS IL DURING MIDDLE OF THE WEEK
BRINGING HOT AND HUMID CONDITIONS WITH HIGHS IN THE LOWER 90S TUE
THROUGH FRI AND AFTERNOON HEAT INDICES OF 98 TO 105F. HAVE
ISOLATED CONVECTION POSSIBLE EACH AFTERNOON AND EARLY EVENING DURING
THE WORK WEEK AND COVERAGE SHOULD BE LIMITED WITH STRONG UPPER
LEVEL RIDGE NEARBY PROVIDING A CAP. BUT HAVE TROPICAL AIRMASS IN
PLACE WITH DEWPOINTS IN THE LOW TO MID 70S.
LONG TERM...FRIDAY THROUGH SUNDAY
MODELS HAVE TRENDED SLOWER WITH FRONTAL BOUNDARY PUSHING SOUTHWARD
THROUGH IL DURING THIS WEEKEND AS UPPER LEVEL RIDGE SHIFTS BACK
SOUTH AND WEAKENS. BEST CHANCES OF CONVECTION STILL APPEARS NORTH
OF CENTRAL IL FRIDAY AND THIS SHIFTS SOUTHWARD INTO CENTRAL IL SAT
AND BEST CHANCES SHIFT INTO SOUTHEAST IL BY SUNDAY. TEMPS TO
GRADUALLY COOL OFF CURING THE WEEKEND WITH HIGHS IN THE LOW TO MID
80S SUNDAY BUT STAYING RATHER HUMID YET WITH DEWPOINTS IN THE
UPPER 60S AND LOWER 70S.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
543 AM MDT SUN JUL 14 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 431 AM MDT SUN JUL 14 2013
MAIN FORECAST CONCERNS WILL PRECIPITATION COVERAGE AND AMOUNTS
THROUGH TONIGHT IT WHAT LOOKS TO BE A COMPLICATED FORECAST DURING
THIS TIME. SATELLITE CONTINUING TO SHOW AN AMPLIFIED AND COMPLICATED
UPPER FLOW PATTERN FROM THE CENTRAL PACIFIC INTO EASTERN NORTH
AMERICA. EASTERLY WAVE/UPPER LOW IS PROGRESSING TOWARD THE AREA.
WEAK FLOW AND VERY MOIST AIR MASS IN PLACE ACROSS THE AREA AT THIS
TIME.
THERE WERE NO PROBLEMS AT JET LEVEL. THE GFS/UKMET WERE DOING A
LITTLE BETTER THAN THE CANADIAN AND SREF AT MID LEVELS. SREF AND
ECMWF WERE DOING BEST ON THE SYNOPTIC SCALE WIND/PRESSURE FIELD
OUTSIDE OF THE MASSIVE INFLUENCE OF ALL THE OUTFLOW BOUNDARIES. THE
GFS/UKMET/SREF DID THE BEST ON THE LOW LEVEL THERMAL FIELD ALTHOUGH
MODELS WERE CLOSE.
TODAY/TONIGHT...OVERNIGHT CONVECTION HAS BEEN SLOWLY WINDING DOWN
OVER THE AREA. NUMEROUS OUTFLOW BOUNDARIES ARE AROUND WITH A COUPLE
OF CONVECTIVE VORTICITY MAXES AROUND AS WELL. BAND OF SHOWERS AND
THUNDERSTORMS HAS DEVELOPED TO THE EAST OF THE AREA. INDIVIDUAL
CELLS ARE MOVING TOWARD THE SOUTH WITH THE AREA MOVING SLOWLY TOWARD
THE WEST. THIS LOOKS TO BE IN RESPONSE A TIGHTENING MID LEVEL
BAROCLINIC ZONE BETWEEN INCOMING UPPER LOW FROM THE EAST AND THE
UPPER RIDGE OVER US.
ONE CONVECTIVE VORTICITY MAX OR 700 MB CIRCULATION STARTS OUT THE
DAY ROUGHLY ALONG THE COLORADO AND KANSAS BORDER. THIS GETS PULLED
SOUTH AS INCOMING UPPER LOW GETS CLOSER. ALSO WHAT LOOKS TO BE
SEVERAL SHORTWAVE TROUGHS ROTATING AROUND PARENT UPPER LOW ARE
EVIDENT. WHAT MAKES ALL OF THIS INTERESTING IS THE PROGRESSION OF
FEATURES FROM EAST TO WEST TODAY. SURFACE CONVERGENCE SETS UP OVER
THE EASTERN PORTION OF THE AREA AND MOVES WEST WITH EAST TO
SOUTHEAST WINDS THEN SPREADING ACROSS THE AREA.
NAM12...HRRR AND RAP INDICATE A LULL IN PRECIPITATION ACTIVITY
THROUGH MID MORNING. CONSIDERING THE DECREASING TREND OF
PRECIPITATION THAT LOOKS REASONABLE. THEN HOW QUICKLY AND WHERE THE
MODELS PUT THE NEXT BATCH OF PRECIPITATION GETS A LITTLE MORE
UNCERTAIN. THE 06Z NAM AND GFS HAVE PULLED THE MAIN AXIS OF
DEVELOPING PRECIPITATION FURTHEST EAST WITH THE NAM THE FURTHEST
EAST OF NOT ONLY THE TWO BUT THE WHOLE MODEL SUITE. THE 00Z ECMWF
TRENDED IN THIS DIRECTION AS WELL. THE LATEST RAP AND HRRR WOULD
SUPPORT THE GUIDANCE WHICH HAS THE MAIN BAND OF PRECIPITATION
DEVELOPING ALONG AND A FEW COUNTIES TO THE EAST OF THE COLORADO
BORDER. CONSIDERING WHERE THE FRONT/SURFACE CONVERGENCE IS...THAT
LOCATION MAKES SENSE.
CURRENT GRIDS THAT WERE JUST ISSUED HAVE THE MAIN BAND ALONG AND TO
THE WEST. DO NOT FEEL CONFIDENT TO ADJUST THAT EVEN NOW. I DID PULL
THE LIKELYS FURTHER EAST AND INCREASED TO HIGHER LIKELYS AS WELL.
WILL BRIEF DAY SHIFT ON THIS TO MAKE ANY SLIGHT ADJUSTMENTS.
RAINFALL WILL PROGRESS TO THE WEST THROUGH THE NIGHT AND BE MOSTLY
DONE BY LATE EVENING. HOWEVER...IF HEAVIER RAIN STARTS FURTHER EAST
THEN THAT WILL HAVE TO BE CHANGED.
HAD EARLIER TOYED WITH THE IDEA OF A FLASH FLOOD WATCH DUE TO THE
HEAVIER RAIN LAST NIGHT. PWS ARE RATHER HIGH 1.5 TO NEARLY
2.0 INCHES. HOWEVER...HEAVIER RAINFALL AMOUNTS WERE SPOTTY AND NOT
WIDESPREAD...FFG IS STILL RATHER HIGH...STORM MOTIONS ARE SLOW BUT
NOT LESS THAN 10 MPH...AND SREF PROBABILITIES OF A HALF INCH TO ONE
INCH OF 6 HOUR RAINFALL ARE VERY LOW. STILL BELIEVE WILL GET
MODERATE TO HEAVY RAINFALL OVER THE WESTERN HALF PER THE PWS AND A
DEEP WARM LAYER IN THE SOUNDINGS.
LOWERED MAXES FOR THE DAY DUE TO EXPECTED CLOUD COVER...DEVELOPING
PRECIPITATION...AND EASTERLY WINDS/COLD AIR ADVECTION. HOWEVER...I
MAY NOT HAVE MADE THEM COOL ENOUGH. LATER TONIGHT THERE MAY BE A LOW
PROBABILITY OF FOG BUT DID NOT INCLUDE AT THIS TIME.
MONDAY/MONDAY NIGHT...DID NOT CHANGE THE GOING FORECAST MUCH
PRECIPITATION WISE. WITH THE POSITION OF THE UPPER LOW AND THE
UPPER RIDGE BUILDING IN FROM THE EAST...MAJORITY OF THE AREA WILL BE
DRY FOR THE ENTIRE PERIOD. THERE WILL BE A VERY LOW CHANCE IN THE
EXTREME SOUTH BUT THAT IS ABOUT IT. DETERMINISTIC AND GEFS
PROBABILITIES SUPPORT THIS. MADE ONLY SLIGHT ADJUSTMENTS TO THE
GOING MAX TEMPERATURE FORECAST WITH GUIDANCE IN DECENT AGREEMENT.
DID COOL OF THE FAR WEST AND SOUTHWEST.
TUESDAY/TUESDAY NIGHT...AREA REMAINS DRY AS MID/UPPER LEVEL RIDGE
BUILDS IN FROM THE EAST. SOUTHERLY SURFACE WINDS INCREASE AS WELL.
MODELS IN DECENT AGREEMENT WITH THE MAXES SO ONLY MADE SLIGHT
ADJUSTMENTS THERE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 431 AM MDT SUN JUL 14 2013
SECOND HALF OF THE WORK WEEK LOOKS DRY AND WARMER AS A WEAK BUT
BROAD UPPER LEVEL RIDGE SITS ACROSS THE EASTERN TWO THIRDS OF THE
CONUS. BREEZY SOUTHERLY WINDS ON WED AND THURS WILL KEEP TEMPS AT OR
ABOVE NORMAL /LOW TO MID 90S/. NO PRECIP IS EXPECTED AND RELATIVE
HUMIDITY WILL REMAIN WELL ABOVE FIRE WX CRITERIA.
TOWARDS THE WEEKEND THE STORY CHANGES AS THE RIDGE IN THE EAST
BREAKS DOWN AND A SMALL BUT RELATIVELY STRONG VORT MAX MOVES ACROSS
NORTHERN COLORADO AND INTO THE CENTRAL HIGH PLAINS...THOUGH GUIDANCE
IS NOT IN VERY GOOD AGREEMENT ON THE PLACEMENT OF THE SYNOPTIC
FORCING. STILL...FEEL THERE IS GOOD ENOUGH AGREEMENT ON THIS AS AN
ASSOCIATED COLD FRONT COULD HELP WITH STORM DEVELOPMENT. MOISTURE
WILL BE NO PROBLEM AS SOUTH/SOUTHWESTERLY WINDS ALOFT WILL HELP TO
ADVECT MOIST MONSOONAL AIR INTO THE REGION...AND IN FACT ON SATURDAY
NIGHT GFS HAS PWATS OF OVER 1.50 INCHES. TEMPS WILL BE WARMEST ON
FRIDAY IN THE MID TO UPPER 90S...DROPPING TO UPPER 80S/LOW 90S ON
SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 539 AM MDT SUN JUL 14 2013
TRICKY/COMPLICATED SET OF TAFS. RARE SCENARIO TODAY THAT CONVECTION
THAT DEVELOPS WILL MOVE INTO THE AREA FROM THE NORTH AND EAST.
THERE LOOKS TO BE A LULL IN THE PRECIPITATION UNTIL THE MID TO
LATE MORNING WHEN PRECIPITATION IS EXPECTED TO DEVELOP. EXPECT THE
THUNDERSTORMS TO HAVE THE MOST AFFECT ON KGLD. DURING THE
AFTERNOON HOURS...THUNDERSTORMS COULD BRING CONDITIONS DOWN TO
MVFR OR JUST ABOVE IT. AFTER THAT FOR KGLD CONDITIONS SHOULD
IMPROVE. AT KMCK CHOSE TO HANDLE WITH A VCTS AT 18Z AT THIS TIME.
IT IS POSSIBLE THAT THUNDERSTORMS DEVELOP JUST TO THE WEST. LATER
TAFS WILL HAVE TO REFINE THE DETAILS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
431 AM MDT SUN JUL 14 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 431 AM MDT SUN JUL 14 2013
MAIN FORECAST CONCERNS WILL PRECIPITATION COVERAGE AND AMOUNTS
THROUGH TONIGHT IT WHAT LOOKS TO BE A COMPLICATED FORECAST DURING
THIS TIME. SATELLITE CONTINUING TO SHOW AN AMPLIFIED AND COMPLICATED
UPPER FLOW PATTERN FROM THE CENTRAL PACIFIC INTO EASTERN NORTH
AMERICA. EASTERLY WAVE/UPPER LOW IS PROGRESSING TOWARD THE AREA.
WEAK FLOW AND VERY MOIST AIR MASS IN PLACE ACROSS THE AREA AT THIS
TIME.
THERE WERE NO PROBLEMS AT JET LEVEL. THE GFS/UKMET WERE DOING A
LITTLE BETTER THAN THE CANADIAN AND SREF AT MID LEVELS. SREF AND
ECMWF WERE DOING BEST ON THE SYNOPTIC SCALE WIND/PRESSURE FIELD
OUTSIDE OF THE MASSIVE INFLUENCE OF ALL THE OUTFLOW BOUNDARIES. THE
GFS/UKMET/SREF DID THE BEST ON THE LOW LEVEL THERMAL FIELD ALTHOUGH
MODELS WERE CLOSE.
TODAY/TONIGHT...OVERNIGHT CONVECTION HAS BEEN SLOWLY WINDING DOWN
OVER THE AREA. NUMEROUS OUTFLOW BOUNDARIES ARE AROUND WITH A COUPLE
OF CONVECTIVE VORTICITY MAXES AROUND AS WELL. BAND OF SHOWERS AND
THUNDERSTORMS HAS DEVELOPED TO THE EAST OF THE AREA. INDIVIDUAL
CELLS ARE MOVING TOWARD THE SOUTH WITH THE AREA MOVING SLOWLY TOWARD
THE WEST. THIS LOOKS TO BE IN RESPONSE A TIGHTENING MID LEVEL
BAROCLINIC ZONE BETWEEN INCOMING UPPER LOW FROM THE EAST AND THE
UPPER RIDGE OVER US.
ONE CONVECTIVE VORTICITY MAX OR 700 MB CIRCULATION STARTS OUT THE
DAY ROUGHLY ALONG THE COLORADO AND KANSAS BORDER. THIS GETS PULLED
SOUTH AS INCOMING UPPER LOW GETS CLOSER. ALSO WHAT LOOKS TO BE
SEVERAL SHORTWAVE TROUGHS ROTATING AROUND PARENT UPPER LOW ARE
EVIDENT. WHAT MAKES ALL OF THIS INTERESTING IS THE PROGRESSION OF
FEATURES FROM EAST TO WEST TODAY. SURFACE CONVERGENCE SETS UP OVER
THE EASTERN PORTION OF THE AREA AND MOVES WEST WITH EAST TO
SOUTHEAST WINDS THEN SPREADING ACROSS THE AREA.
NAM12...HRRR AND RAP INDICATE A LULL IN PRECIPITATION ACTIVITY
THROUGH MID MORNING. CONSIDERING THE DECREASING TREND OF
PRECIPITATION THAT LOOKS REASONABLE. THEN HOW QUICKLY AND WHERE THE
MODELS PUT THE NEXT BATCH OF PRECIPITATION GETS A LITTLE MORE
UNCERTAIN. THE 06Z NAM AND GFS HAVE PULLED THE MAIN AXIS OF
DEVELOPING PRECIPITATION FURTHEST EAST WITH THE NAM THE FURTHEST
EAST OF NOT ONLY THE TWO BUT THE WHOLE MODEL SUITE. THE 00Z ECMWF
TRENDED IN THIS DIRECTION AS WELL. THE LATEST RAP AND HRRR WOULD
SUPPORT THE GUIDANCE WHICH HAS THE MAIN BAND OF PRECIPITATION
DEVELOPING ALONG AND A FEW COUNTIES TO THE EAST OF THE COLORADO
BORDER. CONSIDERING WHERE THE FRONT/SURFACE CONVERGENCE IS...THAT
LOCATION MAKES SENSE.
CURRENT GRIDS THAT WERE JUST ISSUED HAVE THE MAIN BAND ALONG AND TO
THE WEST. DO NOT FEEL CONFIDENT TO ADJUST THAT EVEN NOW. I DID PULL
THE LIKELYS FURTHER EAST AND INCREASED TO HIGHER LIKELYS AS WELL.
WILL BRIEF DAY SHIFT ON THIS TO MAKE ANY SLIGHT ADJUSTMENTS.
RAINFALL WILL PROGRESS TO THE WEST THROUGH THE NIGHT AND BE MOSTLY
DONE BY LATE EVENING. HOWEVER...IF HEAVIER RAIN STARTS FURTHER EAST
THEN THAT WILL HAVE TO BE CHANGED.
HAD EARLIER TOYED WITH THE IDEA OF A FLASH FLOOD WATCH DUE TO THE
HEAVIER RAIN LAST NIGHT. PWS ARE RATHER HIGH 1.5 TO NEARLY
2.0 INCHES. HOWEVER...HEAVIER RAINFALL AMOUNTS WERE SPOTTY AND NOT
WIDESPREAD...FFG IS STILL RATHER HIGH...STORM MOTIONS ARE SLOW BUT
NOT LESS THAN 10 MPH...AND SREF PROBABILITIES OF A HALF INCH TO ONE
INCH OF 6 HOUR RAINFALL ARE VERY LOW. STILL BELIEVE WILL GET
MODERATE TO HEAVY RAINFALL OVER THE WESTERN HALF PER THE PWS AND A
DEEP WARM LAYER IN THE SOUNDINGS.
LOWERED MAXES FOR THE DAY DUE TO EXPECTED CLOUD COVER...DEVELOPING
PRECIPITATION...AND EASTERLY WINDS/COLD AIR ADVECTION. HOWEVER...I
MAY NOT HAVE MADE THEM COOL ENOUGH. LATER TONIGHT THERE MAY BE A LOW
PROBABILITY OF FOG BUT DID NOT INCLUDE AT THIS TIME.
MONDAY/MONDAY NIGHT...DID NOT CHANGE THE GOING FORECAST MUCH
PRECIPITATION WISE. WITH THE POSITION OF THE UPPER LOW AND THE
UPPER RIDGE BUILDING IN FROM THE EAST...MAJORITY OF THE AREA WILL BE
DRY FOR THE ENTIRE PERIOD. THERE WILL BE A VERY LOW CHANCE IN THE
EXTREME SOUTH BUT THAT IS ABOUT IT. DETERMINISTIC AND GEFS
PROBABILITIES SUPPORT THIS. MADE ONLY SLIGHT ADJUSTMENTS TO THE
GOING MAX TEMPERATURE FORECAST WITH GUIDANCE IN DECENT AGREEMENT.
DID COOL OF THE FAR WEST AND SOUTHWEST.
TUESDAY/TUESDAY NIGHT...AREA REMAINS DRY AS MID/UPPER LEVEL RIDGE
BUILDS IN FROM THE EAST. SOUTHERLY SURFACE WINDS INCREASE AS WELL.
MODELS IN DECENT AGREEMENT WITH THE MAXES SO ONLY MADE SLIGHT
ADJUSTMENTS THERE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 431 AM MDT SUN JUL 14 2013
SECOND HALF OF THE WORK WEEK LOOKS DRY AND WARMER AS A WEAK BUT
BROAD UPPER LEVEL RIDGE SITS ACROSS THE EASTERN TWO THIRDS OF THE
CONUS. BREEZY SOUTHERLY WINDS ON WED AND THURS WILL KEEP TEMPS AT OR
ABOVE NORMAL /LOW TO MID 90S/. NO PRECIP IS EXPECTED AND RELATIVE
HUMIDITY WILL REMAIN WELL ABOVE FIRE WX CRITERIA.
TOWARDS THE WEEKEND THE STORY CHANGES AS THE RIDGE IN THE EAST
BREAKS DOWN AND A SMALL BUT RELATIVELY STRONG VORT MAX MOVES ACROSS
NORTHERN COLORADO AND INTO THE CENTRAL HIGH PLAINS...THOUGH GUIDANCE
IS NOT IN VERY GOOD AGREEMENT ON THE PLACEMENT OF THE SYNOPTIC
FORCING. STILL...FEEL THERE IS GOOD ENOUGH AGREEMENT ON THIS AS AN
ASSOCIATED COLD FRONT COULD HELP WITH STORM DEVELOPMENT. MOISTURE
WILL BE NO PROBLEM AS SOUTH/SOUTHWESTERLY WINDS ALOFT WILL HELP TO
ADVECT MOIST MONSOONAL AIR INTO THE REGION...AND IN FACT ON SATURDAY
NIGHT GFS HAS PWATS OF OVER 1.50 INCHES. TEMPS WILL BE WARMEST ON
FRIDAY IN THE MID TO UPPER 90S...DROPPING TO UPPER 80S/LOW 90S ON
SATURDAY.
&&
.AVIATION....(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM MDT SAT JUL 13 2013
VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE
OVERNIGHT HOURS...BUT FLIGHT CATEGORIES WILL BE LOWERING THROUGH
THE DAY ON SUNDAY WITH PRECIPITATION OVERSPREADING THE AREA.
OVERNIGHT...THERE ARE NUMEROUS OUTFLOW BOUNDARIES ASSOCIATED WITH
THUNDERSTORMS IN THE REGION...WIND DIRECTIONS MAY BE HIGHLY
VARIABLE THROUGH THE OVERNIGHT...AND CANNOT COMPLETELY RULE OUT A
BRIEF SHOWER OR THUNDERSTORM...BUT RECENT TRENDS SUGGESTS THEY
WILL NOT IMPACT EITHER TERMINAL FOR THE NEXT FEW HOURS.
SUNDAY...UNUSUAL PATTERN WITH AN UPPER LOW MOVING INTO OKLAHOMA
FROM THE EAST THIS AFTERNOON. PRECIPITATION WILL BE WRAPPING
AROUND THE SYSTEM FROM THE NORTH WITH RAIN AND EMBEDDED
THUNDERSTORMS DEVELOPING AS EARLY AS SUNDAY MORNING AND CONTINUING
THROUGH MOST OF THE DAY. CIGS WILL BE LOWERING AS WELL AS POSSIBLE
VISIBILITY RESTRICTIONS DUE TO RAIN AT BOTH KGLD AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...024
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
631 AM EDT SUN JUL 14 2013
...Updated Aviation Discussion...
.SHORT TERM (Today through Monday)...
Issued at 300 AM EDT Sun Jul 14 2013
The short term period will continue the retrograding pattern with
the upper low now over southeastern Missouri moving west-southwest
to the southern Plains by tonight and Monday, as the upper high now
to our northeast expands westward into the Ohio Valley. In this
pattern, the best chance for convection will be today as a moisture
stream moves northwest between the upper low and high, with
suppressed chances on Monday.
In the near term, skies are clear to partly cloudy over central
Kentucky and southern Indiana, and this will hold through the
morning hours. Isolated showers early over parts of Larue and Hardin
counties have dissipated, and no more than an isolated shower or two
should still pop up elsewhere early this morning if at all. Patchy
fog could develop in a few river valleys by daybreak, otherwise
should not be much of a problem.
During the day today, the moisture stream in the short term models
shows precipitable water values of 1.5 to 2 inches with deep enough
moisture for scattered convective development this afternoon along
any mesoscale or cloud-clear type boundaries. It is difficult to pin
down at this time where cells might develop, although it appears
western parts of south-central Kentucky will have the best chance as
moisture streams up through the Tennessee Valley toward western
Kentucky. This would mean our northeastern counties might only see
isolated cells. This scenario is shown by the HRRR model, although
our in-house WRF develops scattered convection more over our
southeastern counties then propagates them northwest into north-
central Kentucky late this afternoon. Grids will reflect the HRRR,
which is supported by the NAM and GFS as well. In any storms, hail
should be less of a concern today than on Saturday given higher
temperatures aloft, although brief very heavy rain would be more
likely to occur along with CG lightning.
Any diurnal storms should die off this evening with a stabilizing
boundary layer. Skies should also become clear to partly cloudy
again. Patchy fog could develop late tonight in river valleys and
where any rain falls this afternoon.
On Monday, as the upper high builds in and heights and
temperatures aloft rise a bit, and as low-level moisture becomes a
little less prevalent, convection will be more hard pressed to
develop in the afternoon. As a result, while an isolated cell or two
could occur, the chances appear too small to include in the
forecast. Will go with a dry forecast under a partly cloudy sky.
High temperatures today should reach the upper 80s in many areas,
locally held down where showers occur. On Monday, highs should be
around 90 or the lower 90s in most areas, with maximum afternoon
heat indices in the mid to perhaps upper 90s.
.LONG TERM (Monday night through Saturday)...
Issued at 300 AM EDT Sun Jul 14 2013
Most of the upcoming week will degenerate into a broken record of a
forecast, as an anomalously strong upper ridge parks itself over the
Ohio Valley. Main sources of uncertainty center on convective
potential, and whether it will be the heat or the humidity making it
feel like close to 100 degrees each afternoon.
The atmosphere will be quite juicy with PWATs slightly above climo,
providing moderate to strong instability. Limiting factors will be
mid-level warming associated with the ridge, as H7 temps will run
10-11C, and the lack of any synoptic forcing. Convection will be
limited to diurnal activity, with probabilities below mentionable
thresholds in the north for much of the week. Highest POPs will be
in the low-end chance category, and confined to areas south of the
Western Kentucky and Bluegrass Parkways.
Temps are a bit of a crapshoot, as the moist ground is likely to
limit our warming at least in the first part of the week. Max temp
forecast undercuts extended GFS MOS by a few degrees, but still
expect to reach at least the lower 90s. Could see our heating catch
up with guidance later in the week as the heat dries out the ground.
Dewpoints in the lower 70s will push heat indices close to 100, but
any warmer temps will likely be offset by deeper mixing and slightly
lower dewpoints, so confidence is higher in the heat index forecast
than the actual temp or dewpoint forecast. Mins solidly above climo
in the lower to mid 70s each night.
POPs will increase as we head into the weekend, with a solid chance
on Saturday as the ridge starts to break down and we come under more
influence of the westerlies.
&&
.AVIATION (12Z TAF Update)...
Issued at 625 AM EDT Sun Jul 14 2013
Visibilities at BWG and LEX early this morning so far have remained
VFR, and this should continue through daylight hours this morning.
Otherwise, stream of mid-level clouds are moving northwest over
western KY, with clear to partly cloudy skies elsewhere over central
KY. Forecast remains on track for sct-to-bkn clouds around 4 kft or
so to develop by late morning or afternoon, along with some mid
clouds. Scattered afternoon thunderstorms expected in vicinity of
BWG with isolated for SDF and LEX. Conditions will remain VFR except
briefly lower if any convective cells impact the TAF site. Any cells
should weaken/dissipate around 00z or slightly thereafter, with VFR
conditions continuing Sunday night.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......TWF
Long Term........RAS
Aviation.........TWF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
927 AM EDT SUN JUL 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH EARLY NEXT
WEEK WHILE A WEAK COLD FRONT IS EXPECTED TO CROSS THE AREA ON
MONDAY. A STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST
LATER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
925 AM UPDATE...SATELLITE IMAGERY IS SHOWING MID AND HIGH CLOUDS
SPILLING INTO PORTIONS OF THE FORECAST AREA THIS MORNING. HAVE
UPDATED THE SKY COVER FORECAST ACCORDINGLY. OTHERWISE, THE
PREVIOUS FORECAST IS ON TRACK AND NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...CONTINUED WARM AND DRY THIS TERM. A LARGE
RIDGE OF HIGH PRES WILL REMAIN IN CONTROL W/ANOTHER DAY OF VERY
WARM TEMPERATURES.
LATEST SATL IR IMAGERY SHOWED SOME MID AND HIGH CLOUDS ROLLING
OVER THE UPPER RIDGE INTO PORTIONS OF NORTHERN AND EASTERN MAINE.
THE 00Z UA SHOWED A 50KT JETLET IN THE UPPER LEVELS ACROSS QUEBEC
AIDING IN THE CLOUDS PUSHING TOWARD THE CROWN OF MAINE. SOME STRATUS
AND FOG DEVELOPING OVER SWRN MAINE NEAR THE WATERVILLE AREA AND
ANOTHER BATCH SITTING OFF THE MAINE COAST. SATL LOOP SHOWED THIS
STRATUS AND FOG SLOWLY EDGING NORTHWARD TOWARD THE THE DOWNEAST
AND COAST. DECIDED TO ADD SOME PATCHY FOR THE INTERIOR DONWEAST
AND THE COAST. STRATUS AND FOG WILL LIFT AND BURN AFTER SUNRISE
THIS MORNING. THE LATEST HRRR AND LAMP GUIDANCE DOING QUITE WELL
W/THE TEMPERATURE PROFILE ATTM PER THE 06Z OBS AND HAVE LEANED
THIS WAY FOR THE DAYTIME HIGHS TODAY WHICH SHOWS UPPER 80S TO
AROUND 90 AWAY FROM THE COAST. COASTAL AREAS WILL BE COOLER DUE TO
A SEA BREEZE BUT STILL LOW TO MID 80S BEFORE THE BREEZE SETS UP.
THERE IS THE POTENTIAL FOR SOME FOG AGAIN LATER TONIGHT ESPECIALLY
FOR THE DOWNEAST AND COASTAL AREAS. THE LATEST NAM AND GFS
SOUNDINGS PICK THIS UP WELL W/AN INVERSION SETTING UP AND MOISTURE
TRAPPED RIGHT AT THE BLYR. TEMPERATURES OVERNIGHT WILL BE A TAD
WARMER THAN SATURDAY NIGHT W/READINGS EXPECTED TO BE IN THE LOW TO
MID 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A STRONG UPPER LEVEL RIDGE WILL BUILD WESTWARD FROM THE MID
ATLANTIC REGION AND BE CENTERED NEAR THE OH/IN BORDER BY 00Z TUE.
THIS WILL KEEP A WESTERLY FLOW OF VERY WARM AIR ACROSS THE REGION
ON MONDAY. H85 TEMPS OF +17 TO +18 C WITH H925 TEMPS +23 TO +25 C.
EXPECT HIGH TEMPERATURES ON MONDAY TO RANGE FROM THE UPPER 80S TO
LOWER 90S ACROSS MUCH OF THE REGION AWAY FROM THE COAST. A WEAK
COLD FRONT WILL CROSS THE REGION DURING MONDAY AFTERNOON BUT WITH
LITTLE IN THE WAY OF MOISTURE NOT EXPECTING ANYTHING MORE THAN
SOME INCREASING CLOUDS WITH THE PASSAGE OF THE FRONT. EXPECT
MAINLY CLEAR SKIES MONDAY NIGHT WITH LOW TEMPERATURES MAINLY IN
THE 60S. TUESDAY WILL BE ANOTHER MAINLY DRY DAY BUT IT WILL BE A
TAD COOLER THAN MONDAY WITH HIGH TEMPERATURES GENERALLY IN THE LOW
TO MID 80S NORTH AND NEAR 90 DEGREES ACROSS CENTRAL AND INTERIOR
DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE STRONG UPPER RIDGE WILL CONTINUE TO BUILD WESTWARD AND BE CENTERED
NEAR IL BY 00Z THU. AS THE UPPER RIDGE BUILDS WEST THE UPPER FLOW
ACROSS OUR AREA WILL BECOME MORE ZONAL DURING WEDNESDAY ALLOWING A
COLD FRONT TO CROSS THE REGION LATER WEDNESDAY AND WEDNESDAY
EVENING. LOOKS LIKE THE STAGE COULD BE SET FOR STRONG TO POSSIBLY
SEVERE CONVECTION TO DEVELOP WEDNESDAY AFTERNOON. STILL WAY TOO EARLY
FOR ANY MENTION OF ENHANCED WORDING AT THIS TIME BUT THE THREAT WILL
NEED TO BE MONITORED.
THE FRONT WILL MOVE EAST OF THE COAST BY EARLY THURSDAY MORNING AS
COOLER AND DRIER AIR BUILD IN AS HIGH PRESSURE BUILDS EAST. A ZONAL
FLOW WILL KEEP THE CHANCE FOR SHOWERS IN THE FORECAST FOR MUCH OF
THE REMAINDER OF THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL
LEVELS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR THROUGH TONIGHT W/THE EXCEPTION FOR KBGR AND KBHB
AS SOME SHALLOW FOG COULD ALLOW FOR MVFR AND POSSIBLY IFR BRIEFLY
EARLY SUNDAY MORNING.
SHORT TERM: MAINLY VFR MONDAY AND TUESDAY. A COLD FRONT WILL CROSS
THE REGION LATER WEDNESDAY AND WEDNESDAY EVENING. CONFIDENCE IS
INCREASING FOR WIDESPREAD THUNDERSTORMS TO DEVELOP IN ADVANCE OF
THE FRONT WEDNESDAY AFTERNOON RESULTING ON PERIODS OF MVFR/IFR
CONDITIONS IN AND HEAVIER SHOWERS/THUNDERSTORMS. MAINLY VFR
RETURNS FOR THURSDAY.
&&
.MARINE...
NEAR TERM: A SWELL WILL CONTINUE THROUGH TONIGHT W/WAVE HEIGHTS OF
2 FT. WINDS WILL BE LIGHT AVERAGING SPEEDS OF LESS THAN 10 KTS.
SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAY ME
924 AM EDT SUN JUL 14 2013
.SYNOPSIS...
WARMER AND MORE HUMID HIGH PRESSURE BUILDS OVER THE REGION THROUGH
THE MIDDLE OF THE WEEK. IT SHOULD BE MAINLY RAIN FREE THROUGH
TUESDAY. BY MID-WEEK...WE WILL SEE SEVERAL ATTEMPTS BY A COLD
FRONT TO MOVE SOUTH INTO THE HIGH PRESSURE...AND EVEN THOUGH IT
WILL NOT REALLY BREAK THE WARM AND HUMID AIR...IT WILL PRODUCE THE
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
925 AM...I MADE SOME ADJUSTMENTS FOR SKY COVER AS LATEST GOES
IMAGERY INDICATING A LINGERING AREA OF MID CLOUDS ACROSS NORTHERN
NEW HAMPSHIRE INTO WESTERN MAINE. OTHERWISE...I ADJUSTED 1ST
PERIOD GRIDS BASED LARGELY TO REFLECT THE MESONET AND TO
INCORPORATE THE LATEST HRRR OUTPUT INTO SURFACE WIND GRIDS.
PREV DISC...
STRATUS OFFSHORE BEHAVING WELL...AND MAINLY STAYING THERE...BUT
OCCNLY CREEPING ONSHORE BRIEFLY. THIS FOG/CLOUD BANK WILL LKLY
REMAIN OFFSHORE THROUGH THE DAY...BUT SHOULD CREEP BACK FROM THE
COAST THIS MORNING. MEANWHILE OVER NH STRATUS THAT FORMED LAST
EVENING IS NOT HOLDING TOGETHER VERY WELL...AND LOOKS PATCHY FOR
THIS MORNING.
THE 500MB RIDGE BUILDS JUST TO OUR SW TODAY...WITH HEIGHTS
APPROACHING 6000 METERS. THE NAM/GFS CONTINUE TO WANT TO PRODUCE
SOME QPF IN SRN NH AND SW ME AROUND 18Z TODAY...BUT DO NOT SEE IT AS
ANY SORT OF WIDESPREAD EVENT. LOOKING AT THE MESOSCALE MODELS...THE
RAP/HRRR AND LOCAL WRF...IT LOOKS MORE LIKE SOME ISOLD CONVECTION
DEVELOPING. GIVEN THE SURGE OF LOW-LVL MOISTURE THIS MORNING...AND
PERHAPS SOME DIFFERENTIAL HEATING GENERATED FROM LINGERING CLUSTERS
OF STRATUS AND ALTOSTRATUS...THIS MAY BE THE CASE. HAVE CALLED IT
ISOLD SHRA/TSRA...ALTHOUGH WITH DECENT MID-LVL CAPPING IT WILL BE
HARD TO GENERATE ANY TALL CUMULUS AND STRONGER UPDRAFTS.
MAX TEMPS SHOULD CLIMB WELL INTO THE 80S INLAND...WITH A FEW 90S
IN THE HOT SPOTS. LINGERING MORNING CLOUDS COULD SHAVE A DEGREE OR
TWO OFF THE HIGHS IN SOME SPOTS IN SRN NH. AND SEA BREEZE WILL
DEVELOP ALONG THE COAST THIS AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/...
FOR TONIGHT...INLAND AREAS SHOULD CLEAR OF MOST CLOUDS...BUT WILL
HAVE TO WATCH FOR OFFSHORE FOG AND CLOUDS WORKING IN ALONG THE
COAST. WE SHOULD RETURN TO HUMID CONDITIONS...WITH TDS IN THE
60S...THIS WILL LIMIT LOWS TO LOW 60S IN THE N...AND MID TO UPPER
60S EVERYWHERE ELSE.
MONDAY LOOKS TO BE HOT AND HUMID ACROSS ALMOST ALL THE CWA. AS THE
500 MB RIDGE RETROGRADES WWD...WILL SEE MID-UPP LVL ANTICYCLONIC
FLOW DEVELOP...WHICH WILL PRODUCE ENOUGH SUBSIDENCE TO KEEP US HOT
AND RAIN FREE. HIGHS INLAND WILL BE IN THE UPPER 80S TO LOWER 90S
WITH TDS IN THE MID TO UPPER 60S. SHOULD SEE A LITTLE BETTER SW
FLOW AT MID-LVLS...WHICH SHOULD MIX DOWN TO THE SFC A BIT..AND
KEEP SEA BREEZE FROM MOVING AS FAR INLAND AS IT MOVES ONSHORE
LATER IN THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE TO SHOW A WEAKENING BACKDOOR FRONT PUSHING
SOUTHWARD DURING THE DAY TUESDAY AS THE RIDGE OF HIGH PRESSURE
SLIPS SOUTHWARD. THE FRONT THEN LIFTS EAST DURING THE DAY
WEDNESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH THIS
FEATURE...ALTHOUGH ONLY WIDELY SCATTERED SHOWERS/TSTMS POSSIBLE
WITH THIS FEATURE AS ATMOSPHERE ONLY BECOMES SLIGHTLY UNSTABLE.
OTHER WEAKENING FRONTS ARE FORECAST TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY...EACH BRINGING THE THREAT OF SHOWERS OR
THUNDERSTORMS. MODELS CONTINUE TO SHOW A WAVE MOVING ALONG THE
FRONTAL BOUNDARY LATE THURSDAY AND FRIDAY...INCREASING THE THREAT
OF SHOWER AND THUNDERSTORMS LATE IN THE WEEK.
MODELS HAVE BACKED OFF STRONG FRONTAL PASSAGE LATE IN
WEEK...INSTEAD BRINGING A SOMEWHAT WEAKER FRONT THROUGH EARLY
NEXT WEEK.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...MAINLY VFR THROUGH TODAY. FOG/STRATUS JUST NOT
GETTING ORGANIZED...ALTHOUGH IT IS OUT THERE EARLY THIS MORNING.
CANNOT RULE SOME PERIODS OF MVFR THROUGH ABOUT 13Z. FOG/CLOUD BANK
LIKELY TO LINGER OFFSHORE TODAY...AND COULD MOVE ONSHORE AROUND OR
SHORTLY AFTER SUNSET AT THE COASTAL TERMINALS THIS EVENING AND
INTO THE OVERNIGHT. VLY FOG ALSO A POSSIBILITY TONIGHT. ALL
TERMINALS SHOULD BE VFR DURING THE DAY ON MONDAY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED THROUGH THURSDAY WITH
IFR CONDITIONS POSSIBLE IN EARLY MORNING VALLEY FOG IN FAVORED
LOCATIONS. MVFR CONDITIONS ALSO POSSIBLE IN AFTERNOON SHOWERS AND
THUNDERSTORMS EACH DAY. ONLY WIDELY SCATTERED SHOWERS/TSTMS
EXPECTED TUESDAY...BECOMING MORE NUMEROUS BY THURSDAY.
&&
.MARINE...
SHORT TERM...WINDS WILL REMAIN LIGHT AND SEAS BELOW SMALL CRAFT
THRESHOLD. ONLY ISSUE WILL BE LOWERED VSBY AS FOG BANK LOOKS TO
SIT OFFSHORE TODAY...AND POSSIBLY MOVE ONSHORE THIS EVENING.
LONG TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA CRITERIA.
AREAS OF FOG MAY RESTRICT VISIBILITIES...ESPECIALLY IN THE
MORNINGS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
701 AM EDT SUN JUL 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH EARLY NEXT
WEEK WHILE A WEAK COLD FRONT IS EXPECTED TO CROSS THE AREA ON
MONDAY. A STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST
LATER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
655 AM UPDATE: ADJUSTED THE HRLY TEMPERATURES TO ACCOUNT FOR THE
CURRENT CONDITIONS. THE FOG HAS BURNED OFF FOR THE MOST PART
W/SOME PATCHY FOG STILL LINGERING RIGHT ALONG THE IMMEDIATE
COAST AND THIS WILL BURN OFF IN AN HOUR OR SO. REST OF THE FCST
LOOKS OK ATTM.
PREVIOUS DISCUSSION...
CONTINUED WARM AND DRY THIS TERM. A LARGE RIDGE OF HIGH PRES WILL
REMAIN IN CONTROL W/ANOTHER DAY OF VERY WARM TEMPERATURES.
LATEST SATL IR IMAGERY SHOWED SOME MID AND HIGH CLOUDS ROLLING
OVER THE UPPER RIDGE INTO PORTIONS OF NORTHERN AND EASTERN MAINE.
THE 00Z UA SHOWED A 50KT JETLET IN THE UPPER LEVELS ACROSS QUEBEC
AIDING IN THE CLOUDS PUSHING TOWARD THE CROWN OF MAINE. SOME STRATUS
AND FOG DEVELOPING OVER SWRN MAINE NEAR THE WATERVILLE AREA AND
ANOTHER BATCH SITTING OFF THE MAINE. SATL LOOP SHOWED THIS STRATUS
AND FOG SLOWLY EDGING NORTHWARD TOWARD THE THE DOWNEAST AND COAST.
DECIDED TO ADD SOME PATCHY FOR THE INTERIOR DONWEAST AND THE
COAST. STRATUS AND FOG WILL LIFT AND BURN AFTER SUNRISE THIS
MORNING. THE LATEST HRRR AND LAMP GUIDANCE DOING QUITE WELL W/THE
TEMPERATURE PROFILE ATTM PER THE 06Z OBS AND HAVE LEANED THIS WAY
FOR THE DAYTIME HIGHS TODAY WHICH SHOWS UPPER 80S TO AROUND 90
AWAY FROM THE COAST. COASTAL AREAS WILL BE COOLER DUE TO A SEA
BREEZE BUT STILL LOW TO MID 80S BEFORE THE BREEZE SETS UP.
THERE IS THE POTENTIAL FOR SOME FOG AGAIN LATER TONIGHT ESPECIALLY
FOR THE DOWNEAST AND COASTAL AREAS. THE LATEST NAM AND GFS
SOUNDINGS PICK THIS UP WELL W/AN INVERSION SETTING UP AND MOISTURE
TRAPPED RIGHT AT THE BLYR. TEMPERATURES OVERNIGHT WILL BE A TAD
WARMER THAN SATURDAY NIGHT W/READINGS EXPECTED TO BE IN THE LOW TO
MID 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A STRONG UPPER LEVEL RIDGE WILL BUILD WESTWARD FROM THE MID
ATLANTIC REGION AND BE CENTERED NEAR THE OH/IN BORDER BY 00Z TUE.
THIS WILL KEEP A WESTERLY FLOW OF VERY WARM AIR ACROSS THE REGION
ON MONDAY. H85 TEMPS OF +17 TO +18 C WITH H925 TEMPS +23 TO +25 C.
EXPECT HIGH TEMPERATURES ON MONDAY TO RANGE FROM THE UPPER 80S TO
LOWER 90S ACROSS MUCH OF THE REGION AWAY FROM THE COAST. A WEAK
COLD FRONT WILL CROSS THE REGION DURING MONDAY AFTERNOON BUT WITH
LITTLE IN THE WAY OF MOISTURE NOT EXPECTING ANYTHING MORE THAN
SOME INCREASING CLOUDS WITH THE PASSAGE OF THE FRONT. EXPECT
MAINLY CLEAR SKIES MONDAY NIGHT WITH LOW TEMPERATURES MAINLY IN
THE 60S. TUESDAY WILL BE ANOTHER MAINLY DRY DAY BUT IT WILL BE A
TAD COOLER THAN MONDAY WITH HIGH TEMPERATURES GENERALLY IN THE LOW
TO MID 80S NORTH AND NEAR 90 DEGREES ACROSS CENTRAL AND INTERIOR
DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE STRONG UPPER RIDGE WILL CONTINUE TO BUILD WESTWARD AND BE CENTERED
NEAR IL BY 00Z THU. AS THE UPPER RIDGE BUILDS WEST THE UPPER FLOW
ACROSS OUR AREA WILL BECOME MORE ZONAL DURING WEDNESDAY ALLOWING A
COLD FRONT TO CROSS THE REGION LATER WEDNESDAY AND WEDNESDAY
EVENING. LOOKS LIKE THE STAGE COULD BE SET FOR STRONG TO POSSIBLY
SEVERE CONVECTION TO DEVELOP WEDNESDAY AFTERNOON. STILL WAY TO EARLY
FOR ANY MENTION OF ENHANCED WORDING AT THIS TIME BUT THE THREAT WILL
NEED TO BE MONITORED.
THE FRONT WILL MOVE EAST OF THE COAST BY EARLY THURSDAY MORNING AS
COOLER AND DRIER AIR BUILD IN AS HIGH PRESSURE BUILDS EAST. A ZONAL
FLOW WILL KEEP THE CHANCE FOR SHOWERS IN THE FORECAST FOR MUCH OF
THE REMAINDER OF THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL
LEVELS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR THROUGH TONIGHT W/THE EXCEPTION FOR KBGR AND KBHB
AS SOME SHALLOW FOG COULD ALLOW FOR MVFR AND POSSIBLY IFR BRIEFLY
EARLY SUNDAY MORNING.
SHORT TERM: MAINLY VFR MONDAY AND TUESDAY. A COLD FRONT WILL CROSS
THE REGION LATER WEDNESDAY AND WEDNESDAY EVENING. CONFIDENCE IS
INCREASING FOR WIDESPREAD THUNDERSTORMS TO DEVELOP IN ADVANCE OF
THE FRONT WEDNESDAY AFTERNOON RESULTING ON PERIODS OF MVFR/IFR
CONDITIONS IN AND HEAVIER SHOWERS/THUNDERSTORMS. MAINLY VFR
RETURNS FOR THURSDAY.
&&
.MARINE...
NEAR TERM: A SWELL WILL CONTINUE THROUGH TONIGHT W/WAVE HEIGHTS OF
2 FT. WINDS WILL BE LIGHT AVERAGING SPEEDS OF LESS THAN 10 KTS.
SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 AM EDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EDT SUN JUL 14 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG
EXTENDING WWD FM THE NE CONUS THRU THE GREAT LKS ON THE SE FLANK OF
FASTER WSW FLOW ALF OVER CANADA. 00Z APX RAOB SHOWS A STABLE...BONE
DRY AIRMASS /PWAT 0.77 INCH/ CLOSER TOWARD THE CORE OF THIS UPR RDG.
SO THE SE HALF OF THE CWA IS MOCLR. FARTHER TO THE W...THERE IS A
BAND OF MAINLY MID CLDS STRETCHING FM THE NW HALF OF LK SUP SWWD
THRU MN AND INTO IOWA. IN FACT...THE 00Z MPX RAOB SHOWS A GOOD DEAL
OF MID LVL MSTR WITH PWAT 1.93 INCH...188 PCT OF NORMAL. BUT AN
ABSENCE OF ANY SGNFT DYNAMIC FORCING UNDER THE UPR RDG AXIS WITH THE
00Z GRB/MPX RAOBS INDICATING A CAPPING INVRN THAT WEAKENS A BIT
FARTHER TO THE W AWAY FM THE HIER HGTS HAS IS ALLOWING FOR ONLY SOME
ISOLD -SHRA OVER MAINLY WRN UPR MI AND NW WI WHERE THE RUC ANALYSIS
SHOWS A BIT HIER H7 DEWPTS NEAR 10C. ANOTHER FACTOR TENDING TO
RESTRICT THE SHRA COVERAGE/INTENSITY IS A FEED OF DRIER SFC-H85 AIR
FM THE S SHOWN ON THE 00Z QUAD CITIES IOWA RAOB. SPC MESOANALYSIS
INDICATES MUCAPE NOT MUCH HIER THAN 100-250 J/KG. FARTHER TO THE
NW...A FAIRLY POTENT SHRTWV JUST W OF LK WINNIPEG EMBEDDED IN THE
WSW FLOW ALF OVER CANADA IS CAUSING SOME SCT SHRA/TS UNDER AXIS OF
GREATER INSTABILITY OVER NDAKOTA/FAR NW MN. BUT VERY DRY AIRMASS
SHOWN ON THE 00Z INL RAOB IS LIMITING THE EWD PUSH OF THESE SHRA.
TODAY...AS THE UPR RDG AXIS EXPANDS TO THE W AND H7 HGTS RISE
ACCORDINGLY...MODELS IN GOOD AGREEMENT SHOWING SE EDGE OF HIER H7
DEWPTS RETREATING SLOWLY TO THE NW AS WELL. LOWER H85 DEWPTS
ARRIVING FM THE S WL ALSO TEND TO END ANY SHRA. SO WL FCST LINGERING
POPS OVER THE NW LAND CWA THIS MRNG TO PUSH OUT INTO LK SUP. WITH
ABUNDANT SUNSHINE OVER THE CENTRAL AND E ALONG WITH H85 TEMPS NEAR
17C...EXPECT HI TEMPS TO RISE WELL INTO THE 80S AGAIN AWAY FM THE
MODERATING INFLUENCE OF MAINLY LK MI IN LLVL SSW FLOW. BUT RATHER
WEAK PRES GRADIENT FCST THIS AFTN WL ALLOW FOR LK BREEZE FORMATION
OFF LK SUP AS WELL.
TONIGHT...MODELS IN GOOD AGREEMENT SHOWING AXIS OF HIER H7 MSTR
REMAINING OVER NW LK SUP OVERNGT ON THE NW FLANK OF NEARLY STNRY UPR
RDG CENTERED OVER THE LOWER GRT LKS. ANOTHER SHRTWV IS FCST TO RIDE
NEWD THRU MN LATE TNGT IN THE WSW FLOW ALF ARND THE RDG...BUT BULK
OF MODELS INDICATE ANY ASSOCIATED PCPN WL REMAIN OVER THE LK WITH
MID LVL CAPPING OVER THE LAND CWA CLOSER TO THE HIER HGTS DESPITE
ARRIVAL OF MORE HUMID LLVL AIR THAT WL ALLOW FOR SOME FOG FORMATION
AT LEAST OVER THE W HALF.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM EDT SUN JUL 14 2013
UPPER LEVEL HIGH CENTERED OVER MID ATLANTIC EXPANDS WESTWARD ACROSS
THE OHIO VALLEY AND MISSISSIPPI RIVER VALLEY INTO WEDNESDAY. LATER
WEDNESDAY THROUGH THURSDAY NORTHERN STREAM TROUGH/MID-LEVEL SPEED
MAX SMASHES THE RIDGE SOUTH OF UPPER GREAT LAKES. APPEARS THAT
NORTHERN STREAM TROUGH WILL BE STRONG ENOUGH TO PUSH SFC-H85 FRONT
ACROSS UPR MICHIGAN WED AFTN THROUGH THURSDAY. TROUBLE IS THAT FRONT
WILL NOT MOVE TOO FAR SOUTH AS IT BECOMES PARALLEL TO UPPER FLOW.
WITH FRONT CLOSE BY AND SINCE UPPER LAKES WILL BE ON NORTHERLY EDGE
OF HIGHER INSTABILITY GRADIENT AND ON SOUTHERN EDGE OF STRONGER
WINDS ALOFT...WILL HAVE CHANCE POPS WEDNESDAY THROUGH THURSDAY
NIGHT. AT THIS POINT...BEST CHANCES OF WIDESPREAD SHRA/TSRA WOULD BE
WEDNESDAY THEN AGAIN THURSDAY AFTN/EVENING. BY LATER FRIDAY AND INTO
NEXT WEEKEND...HEIGHTS FROM THE NORTH LOWER ENOUGH TO PUSH FRONT FAR
ENOUGH SOUTH TO SHOW A DRYING TREND.
HIGH PRESSURE BUILDING ALOFT ON MONDAY WHILE WEAK HIGH PRESSURE IS
OVER THE AREA AT THE SFC. COULD BE LOCALIZED LAKE BREEZES OFF LK
SUPERIOR NCNTRL AND ON KEWEENAW. PATTERN FAVORS MOST LAKE COOLING
OFF LK MICHIGAN THOUGH. WEAK CONVERGENCE ALONG LK BREEZES BUT
MLCAPES ARE MEAGER WITH SUBSIDENCE FROM BUILDING RIDGE ALOFT.
CU MAY BE ENHANCED OVR CNTRL CWA BUT WILL NOT INCLUDE ANY POPS
DUE TO MINIMAL INSTABILITY. SFC RIDGE AXIS MOVES EAST BY TUESDAY
WHILE SFC TROUGH CROSSES NORTHERN MANITOBA AND NORTHWEST ONTARIO.
GRADIENT SSW WIND SHOULD LIMIT LAKE SUPERIOR BREEZE. H85 TEMPS SURGE
TO +18C...SO EXPECT TEMPS INTO THE UPPER 80S AWAY FM LK MICHIGAN.
HIGHER DWPNT/INSTABILITY THAN MONDAY WITH MLCAPES OVER 1000
J/KG...BUT OVERALL THE LOW-LEVEL CONVERGENCE IS MINIMAL. COULD
SEE ISOLD-SCT SHRA/TSRA FORM OVER CNTRL CWA NEAREST LK MICHIGAN LAKE
BREEZE. WITH DEEP LAYER SHEAR OVER 30 KTS...CANNOT RULE OUT AN ISOLD
SVR STORM.
GENESIS REGION FOR MORE ORGANIZED SHRA/TSRA ON TUESDAY EVENING MAY
BE IN THE VCNTY OF UPPER LAKES INTO NORTHERN PLAINS CLOSER TO TAIL
END OF SFC TROUGH EXTENDING SOUTHWEST OF SFC LOW CROSSING NORTHERN
ONTARIO. MAX MOISTURE ADVECTION/LOW-LEVEL JET WOULD BE OVER NW
PORTION OF UPPER LAKES. MEAN STORM MOTION/FORWARD PROPAGATING
CORFIDI VECTORS AND 850-300MB THICKNESS SUGGEST THAT IF SHRA/TSRA
FORM IN THE EVENING THEY WOULD TRACK ACROSS UPR MICHIGAN TUE NIGHT.
WILL GO WITH LOW CHANCES ON TUESDAY NIGHT ACROSS WESTERN CWA. IDEA
MATCHES SPC SREF 3 HR PROBABILITY FOR TSRA. IF ORGANIZED CONVECTION
MATERIALIZES...WOULD AGAIN BE SOME RISK OF SVR MAINLY IN THE FORM OF
STRONG WIND GUSTS.
SFC FRONT AND DWPNTS POOLING TO NEAR 70 DEGREES IN AREA ON
WEDNESDAY. DEPENDING HOW OVERNIGHT CONVECTION GOES THERE MAY BE AN
INITIAL ROUND OF SHRA/TSRA OVER THE AREA ON WEDNESDAY MORNING WITH
ANOTHER INCREASE DURING THE AFTN. MLCAPES PUSHING 1500J/KG WITH DEEP
LAYER SHEAR 30-40 KTS INDICATES THIS COULD BE YET ANOTHER SVR
WEATHER DAY. SYNOPTIC PATTERN POINTS TO WIND/BOW ECHO TYPE OF
SITUATION. MUCH TOO EARLY TO GET CAUGHT UP IN THESE DETAILS YET
THOUGH. SOME INDICATIONS THAT FRONT MAY BE THROUGH NORTHERN TIER OF
CWA WITH MAIN FOCUS FOR AFTN CONVECTION OVER THE SCNTRL IN AREA OF
STRONGER SFC-H85 CONVERGENCE. CONSENSUS POPS HAVE THE HIGHER POPS
SCNTRL WITH LESSER POPS NEAR LK SUPERIOR. TEMPS COULD SHOW A PRETTY
SHARP RANGE ON WEDNESDAY...ESPECIALLY IF ONSHORE NORTH WINDS DEVELOP
IN THE NORTH CWA EARLIER IN THE DAY. MIXING TO H85 TEMPS STILL NEAR
+17C YIELDS HIGHS INTO THE UPPER 80S SCNTRL. 70S TO NEAR 80 DEGREES
WILL BE THE CASE NEAR LK SUPERIOR. OVERALL A LULL EXPECTED LATER
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. BY THURSDAY AFTN...SFC-H85
WINDS BACKING MORE SW AHEAD OF ANOTHER SHORTWAVE/H5 SPEED MAX
DIGGING INTO NORTHERN PLAINS. H85 WARM AIR ADVECTION ALONG WITH
MOISTURE TRANSPORT AND FACT THAT UPR MICHIGAN IS FCST TO BE ALONG
NORTH EDGE OF MUCAPE GRADIENT SUGGESTS ANOTHER ROUND OF SHRA/TSRA
OVER PARTS OF THE AREA THURSDAY AFTN/THURSDAY NIGHT. MAY EVEN SEE
ANOTHER CONVECTIVE WIND TYPE OF SITUATION.
CONSENSUS POPS SHOW THE DRYING TREND KICKING IN ON FRIDAY FM NORTH
TO SOUTH AS MAIN SFC COLD FRONT PLOWS INTO THE REGION. EXPECT DRY
WEATHER AND COOLER TEMPERATURES TO BE MAIN WEATHER STORY BY TIME
NEXT WEEKEND ARRIVES. ONSHORE GRADIENT NORTH WINDS LIKELY WILL KEEP
TEMPS IN THE 60S ALONG LK SUPERIOR FRIDAY AND SATURDAY. MAY ALSO SEE
INCREASED SWIM RISK AT THAT TIME AS WELL. IN THE MEANTIME...A WARM
AND HUMID SUMMERTIME REGIME WILL BE IN PLACE THROUGH MUCH OF THE
UPCOMING WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 741 AM EDT SUN JUL 14 2013
SOME LINGERING SCT -SHRS NEAR CMX/IWD THIS MRNG WL TEND TO DIMINISH
THIS MRNG UNDER RISING HGTS ASSOCIATED WITH BLDG RDG IN THE GREAT
LKS AND ARRIVAL OF DRIER AIR. EVEN IF ANY -SHRA IMPACT THESE
SITES...DRY LLVLS WL ENSURE VFR CONDITIONS. THEN VFR WX WL PREVAIL
THRU TNGT AT CMX/IWD AS THE RDG EXPANDS SLOWLY TO THE NW AND
DEFLECTS ANY ADDITIONAL SHRA/TS TO THE NW. SAW WL BE CLOSER THE RDG
AND DRIER AIR...SO EXPECT VFR CONDITIONS TO PREVAIL THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EDT SUN JUL 14 2013
WITH HIGH PRESSURE NUDGING INTO THE UPPER GREAT LAKES AND A WEAK LOW
PRESSURE TROUGH TO THE WEST...WINDS WILL GENERALLY REMAIN LESS THAN
15-20 KNOTS THROUGH THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
942 AM MDT SUN JUL 14 2013
.UPDATE...
ADJUSTED POPS A LITTLE TODAY FOR THE MORNING UPDATE. TWO AREAS OF
CONCERN ON RADAR THIS MORNING. FIRST WAS THE ISOLATED
THUNDERSTORMS OVER THE EASTERN PART OF THE AREA DUE TO 850-700
FRONT AND ELEVATED INSTABILITY. THIS FRONT GRADUALLY DISSOLVES
THIS AFTERNOON. A WARM FRONT WAS TAKING SHAPE SW OF THE REGION
THIS MORNING. THE WARM FRONT WAS COMBINING WITH LIFT FROM A
SHORTWAVE OVER N ID...SEEN ON WATER VAPOR IMAGERY...TO BRING A
FEW SHOWERS TO SW MT ON RADAR. THESE SHOWERS WERE MOVING NE TOWARD
THE FORECAST AREA. AS THE DAY PROGRESSES...STRONG ISENTROPIC LIFT
WILL DEVELOP ON THE NORTHWARD MOVING WARM FRONT OVER THE S CENTRAL
PART OF THE AREA. HAVE INCREASED POPS IN THIS REGION THIS
AFTERNOON AND EVENING. ADDED POPS TO THE SW THIS MORNING AS WELL.
THE E WILL HAVE LOW POPS DUE TO THIS MORNING/S 850-700 MB FRONT
AND THE APPROACHING WARM FRONT. A WEAKER WAVE WILL MOVE INTO THE
SW THIS AFTERNOON ADDING TO LIFT OVER THE AREA AS WELL.
PRECIPITABLE WATERS WILL REMAIN NEAR AN INCH OVER THE AREA WHICH
WILL ALLOW THUNDERSTORMS TO PRODUCE HEAVY RAINFALL ONCE AGAIN.
WRF HAD DECENT INSTABILITY OF 500-1000 J/KG OF CAPE OVER THE
CENTRAL ZONES...WHILE RAP HAD AROUND 500 J/KG W AND CENTRAL. THERE
WAS ALSO SOME DECENT SHEAR OVER THE AREA. SOME STORMS COULD BECOME
STRONG W AND CENTRAL LATE TODAY INTO THE EVENING. THE E WILL BE
CAPPED BUT LIFT SHOULD BE ABLE TO TAP THE ELEVATED INSTABILITY TO
SUPPORT THUNDER. TEMPERATURES IN THE 70S AND 80S WERE ON TRACK.
ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND MON...
SYNOPSIS...WEAK FORCING WILL HOLD STRONG THUNDERSTORM POTENTIAL DOWN
DESPITE UPSLOPE WINDS AND PLENTY OF MOISTURE IN PLACE THE NEXT
COUPLE OF DAYS. COLD FRONT PUSHED THROUGH THE AREA BY EARLY LAST
EVENING WITH ELEVATED 700MB FRONTOGENESIS BAND STILL GENERATING
SCATTERED SHOWER BANDS OVER EASTERN HALF OF THE FORECAST AREA.
SURFACE HIGH OVER SOUTHERN SASKATCHEWAN WILL SHIFT SOUTHEAST TODAY
TURNING LOW LEVEL WINDS EASTERLY. THIS WILL ADVECT IN HIGHER
DEWPOINT AIR AND PROVIDE LIFT INTO AREA FOOTHILLS/MOUNTAINS VIA
UPSLOPE GRADIENT.BY THIS EVENING WINDS WILL BEGIN TO TURN
SOUTHERLY OVER WESTERN AREAS AS LEE SIDE TROFING BEGINS TO
DEVELOP. THIS WILL ALLOW HOTTER AND DRIER AIR FROM THE GREAT BASIN
TO SPILL BACK INTO THE AREA FOR MONDAY. NOT MUCH IN THE WAY OF
FORCING ON MONDAY BUT HOT TEMPERATURES OVER THE HIGHER TERRAIN
SHOULD BE ENOUGH FOR ISOLATED TO SCATTERED HIGH BASED
THUNDERSTORMS...THOUGH VERY WARM 700MB TEMPERATURES WILL LIKELY
PREVENT STORMS FROM MAINTAINING OVER THE LOWER ELEVATIONS. ANOTHER
PACIFIC DISTURBANCE WILL SLIDE EASTWARD ALONG THE CANADIAN BORDER
MONDAY NIGHT. THIS WILL PUSH A COLD FRONT THROUGH THE AREA
OVERNIGHT PROVIDING FOCUS FOR ADDITIONAL SHOWER AND THUNDERSTORM
DEVELOPMENT INTO TUESDAY.
TODAY...700 MB FRONTOGENESIS BAND COMBINED WITH A VERY WEAK
DISTURBANCE SLIDING NORTHEAST OUT OF WYOMING WILL PROVIDE LIFT
OVER SOUTHEAST MONTANA THIS MORNING. MODELS PRETTY BULLISH ON
SCATTERED SHOWERS/THUNDESTORMS OVER THIS AREA THROUGH THE MORNING
HOURS AND HAVE KEPT 40 TO 50 POPS IN PLACE. DESPITE PRECIPITABLE
WATER VALUES IN THE 1.2 TO 1.4 INCH RANGE HAVE KEPT MENTION OF
HEAVY RAIN OUT OF THE FORECAST FOR NOW BASED ON LACK OF STRONGER
FORCING MECHANISM FOR DEEP CONVECTION...BUT LOCALLY HEAVY RAINFALL
IS NOT OUT OF THE QUESTION EAST OF A MILES CITY TO SHERIDAN LINE
TODAY. LATER THIS AFTERNOON EXPECT DIURNAL INSTABILITY TO COMBINE
WITH EASTERLY LOW LEVEL WINDS TO PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS OVER EAST/NORTH FACING SLOPES OF AREA MOUNTAINS.
STORMS WILL DRIFT NORTHEAST AND SHOULD PERSIST WELL INTO THE
EVENING WITH AN ASSIST FROM A WEAK UPPER WAVE EMBEDDED IN THE FLOW
ALOFT. ONCE HEATING DECLINES DURING THE MID TO LATE EVENING HOURS
WILL SEE CONVECTION DISSIPATE WITH JUST A FEW LINGERING CELLS
OVERNIGHT OVER EASTERN AREAS AS THE UPPER WAVE PUSHES THROUGH.
TEMPERATURES IN THE MID 80S SEEM REASONABLE FOR MOST AREAS TODAY
WITH EASTERLY LOW LEVEL WINDS LIMITING MIXING.
MONDAY...OVERNIGHT WILL SEE LOW TO MID LEVEL WARM ADVECTION KICK
IN AS SURFACE WINDS TURN SOUTHWESTERLY DUE TO LEE SIDE TROFING AND
MID LEVELS WARM IN ADVANCE OF NEXT PACIFIC TROF. THIS WARMING AND
DRYING WILL ALLOW TEMPERATURES TO REBOUND INTO THE MID 90S FOR
MOST LOCATIONS MONDAY AFTERNOON. WITH TEMPERATURES IN THE 90S AND
PLENTY OF LOW LEVEL MOISTURE IN PLACE EAST OF A ROUNDUP TO
BILLINGS LINE SHOULD SEE CAPE VALUES OVER 1000 J/KG DURING THE
AFTERNOON WITH DECENT SHEAR PROFILES. HOWEVER CAPPING INVERSION
AND LACK OF ANY FORCING WILL LIKELY KEEP A LID ON STORMS MONDAY
AFTERNOON IN THESE AREAS AND HAVE KEPT JUST A 20 PERCENT CHANCE IN
THE FORECAST IN CASE A FEW CELLS ARE ABLE TO BREAK THE CAP...AND
LEFT ANY MENTION OF STRONG STORMS OUT OF THE FORECAST FOR THESE
REASONS AS WELL. WEST OF THE ROUNDUP TO BILLINGS LINE MOISTURE
WILL BE MORE LIMITED AS SOUTHWESTERLY WINDS MIX LOW LEVEL MOISTURE
OUT IN THE AFTERNOON. THERE IS NOT MUCH IN THE WAY OF FORCING TO
GENERATE CONVECTION...HOWEVER WITH THE EXPECTED HOT TEMPERATURES
SHOULD BE ABLE TO GENERATE HIGH BASED CONVECTION OVER THE
MOUNTAINS. THIS CONVECTION WILL LIKELY PRODUCE MORE WIND GUSTS
THAN RAIN AND IT WILL HAVE A HARD TIME SUSTAINING OUT INTO THE
PLAINS DUE TO +14C AIR AT 700MB.
COLD FRONT LATE MONDAY NIGHT IS PROBABLY THE BEST CHANCE FOR
PRECIPITATION DURING THIS PERIOD. ONCE AGAIN THE BEST FORCING
WITH THIS SYSTEM WILL REMAIN WELL TO THE NORTH OF THE AREA SO
LIMITED SHOWERS AND THUNDERSTORM TO ISOLATED/SCATTERED COVERAGE.
HOWEVER MOISTURE ADVECTION INTO THE FRONT AND STRENGTH OF THE
FRONTAL PUSH SHOULD PROVIDE SOME AREAS WITH A CHANCE AT A TENTH
OR MORE OF PRECIPITATION OVERNIGHT. CHAMBERS
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
HEIGHTS WILL BEGIN TO REBOUND TUESDAY IN THE WAKE OF SHORTWAVE
ACROSS SOUTHERN CANADA...THE FEATURE CURRENTLY DROPPING THROUGH
BRITISH COLUMBIA. STRONGLY CONFLUENT FLOW OVER THE REGION SUPPORTS
LEE SIDE SFC RIDGING ON TUE...AND THE LATEST MODEL RUNS HAVE
TRENDED A BIT STRONGER WITH THIS RIDGE AND RESULTANT LOW LEVEL
COOLING IN SOUTHEAST MT...ESPECIALLY IN OUR WESTERN UPSLOPE AREAS.
HAVE DROPPED EXPECTED HIGH TEMPS IN OUR WEST BUT HAVE NOT GONE AS
LOW AS GUIDANCE PER THE 590ISH HEIGHTS BUILDING IN. ALSO...DESPITE
THE LOW LEVEL STABILIZING...ELEVATED INSTABILITY SHOULD REMAIN...
AND WITH WEAK ENERGY LIFTING OUT OF THE GREAT BASIN CANNOT
DISCOUNT SOME SHOWER OR WEAK TSTM ACTIVITY TUESDAY INTO TUESDAY
NIGHT. OVERALL AN INTERESTING WEATHER DAY.
UPPER RIDGE WILL DOMINATE THE REGION THROUGH THE END OF THE WEEK
BUT PERHAPS NOT AS STRONGLY AS PREVIOUSLY THOUGHT...ESPECIALLY AS
PACIFIC ENERGY MAY BEGIN TO SUPPRESS HEIGHTS FURTHER BY NEXT
WEEKEND. PRECIPITABLE WATERS WILL BE QUITE HIGH WED/THU/FRI...A
RESULT OF EASTERLY LOW LEVEL WINDS AND MONSOONAL FLOW FROM THE
GREAT BASIN. CONVECTION WILL FIRE OVER THE HIGH TERRAIN EACH OF
THESE DAYS AND HAVE RAISED POPS TO ABOVE CLIMATOLOGY BASED ON THE
MOISTURE THAT WILL BE PRESENT. A FEW STORMS MAY DRIFT OVER THE
PLAINS BUT THEY SHOULD BE LARGELY UNORGANIZED. THIS CONVECTION
WILL BE IN WEAK SHEAR ENVIRONMENTS AND BATTLE WARM MID LEVEL
TEMPS SO DO NOT SEE A SEVERE RISK...BUT COULD BE SOME HEAVY RAIN
GIVEN THE MOISTURE AND WHAT SHOULD BE SLOW MOVING STORMS. PACIFIC
FLOW MAY INCREASE BY NEXT WEEKEND AND ALLOW FOR A BIT DRIER AIR TO
ADVECT FROM THE WEST...SO WILL KEEP THE FORECAST MOSTLY DRY NEXT
SAT/SUN. TEMPS SHOULD REMAIN ABOVE NORMAL BUT NOT DRAMATICALLY
SO...WITH HIGHS GENERALLY IN THE UPPER 80S TO MID 90S. MODELS HAVE
ACTUALLY TRENDED A BIT COOLER...AGAIN PER THE RIDGE BEING NOT
QUITE AS STRONG...SO HAVE TWEAKED TEMPS DOWN SLIGHTLY FOR SOME
PERIODS.
JKL
&&
.AVIATION...
EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON WITH
LOCAL MVFR POSSIBLE IN HEAVY DOWNPOURS. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 084 061/094 065/084 061/090 066/092 065/093 065/094
3/T 22/T 22/T 22/T 22/T 22/T 21/B
LVM 084 052/090 053/085 054/091 055/092 056/093 052/095
4/T 43/T 33/T 33/T 33/T 32/T 22/T
HDN 084 061/096 062/087 059/092 061/093 063/093 061/095
4/T 22/T 22/T 22/T 22/T 22/T 21/B
MLS 082 065/095 068/089 063/093 068/093 066/093 067/094
3/T 22/T 22/T 22/T 22/T 22/T 21/B
4BQ 082 062/093 063/091 060/093 063/091 065/090 061/092
3/T 32/T 22/T 21/U 12/T 22/T 21/B
BHK 078 060/089 064/088 061/091 064/090 064/088 062/089
3/T 22/T 22/T 21/B 22/T 22/T 22/T
SHR 083 058/091 058/089 058/092 058/091 058/090 057/092
4/T 42/T 22/T 22/T 22/T 23/T 31/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
924 AM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 923 AM CDT SUN JUL 14 2013
UPDATED THROUGH THE AFTERNOON TO ADJUST FOR QUASI-STATIONARY BAND
OF CONVECTION. LEANED ON THE HRRR THROUGH 18Z AND SREF THROUGH 00Z
TO BLEND. HAVE UPPED THE QPF TO ACCOUNT FOR THE OBSERVED HEAVIER
RAINS IN PROGRESS. A PWS IN HOFFMAN/GRANT COUNTY/SHOWS 1.8 INCHES
MIDNIGHT THROUGH 9AM. BIAS FFMP/LEGACY AND DUAL POL QPE A TAD HOT
BUT HAVE GENERAL IDEA. WILL BLEND TEMPS DOWN IN CLOUDS AND RAIN
AREAS AS WELL.
UPDATE ISSUED AT 640 AM CDT SUN JUL 14 2013
HAVE CANCELED SVR TSTM WATCH FOR FAR SERN ND COUNTIES. INCREASING
CONVECTION OVER SERN SD AND DECREASING LLJET HAVE LIMITED THE LOW
LEVEL MOISTURE CONVERGENCE INTO NERN SD AND OUR SOUTHERN FA. SFC
BOUNDARY REMAINS STALLED ACROSS SERN ND INTO NWRN MN... ROUGHLY
ALG AN ABR-FAR-BDE LINE. SOUTH OF THIS BOUNDARY...DEEP CONVECTION
HAS INCREASED FROM ERN SD INTO CNTRL MN. THIS AREA SHUD REMAIN
ACTIVE THROUGHOUT THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 355 AM CDT SUN JUL 14 2013
A SURFACE BOUNDARY IS DRAPED ACROSS THE FA AND EXTENDS FROM A LOW
PRESSURE CENTER IN WRN NE... THROUGH ECNTRL ND INTO NORTHWEST ONT.
DEWPTS FROM THE UPPER 60S TO LOWER 70S CONTINUE TO PILE UP AHEAD
OF THE BOUNDARY... AND WITH A WEAK 850 LLJET EXTENDING UP FROM ERN
SD... SHUD MAINTAIN AN AREA OF +1000 MUCAPE INTO SERN ND AND
PORTIONS OF WCNTRL MN THROUGH THE MORNING.
A CONVECTIVE COMPLEX NOW PUSHING FM NCNTRL SD INTO NERN SD IS
EXPECTED TO DRIVE INTO THIS UNSTABLE AIRMASS AND PERHAPS PENETRATE
TO THE MN BORDER WITH STRONG TO SEVERE WIND POTENTIAL. THE COMPLEX
IS MOVING AWAY FROM ITS AREA OF BEST DEEP LAYER SHEER AND BUMPING
UP AGAINST A SOMEWHAT WARMER MID LEVEL WARM POCKET... SO LONGEVITY
IS IN QUESTION. EXPECT THIS EARLY CONVECTIVE COMPLEX TO WEAKEN
AND DISSIPATE THROUGH MID MORNING.
THAT ALL SAID... H7 TEMPS ARE EXPECTED TO COOL A BIT FURTHER INTO
THIS AFTERNOON OVER SERN ND AND NWRN MN WHILE LOW LEVEL MOISTURE
TRANSPORT KICKS UP A BIT. WITH THIS...AREAS ALONG AND AHEAD OF
THE SURFACE BOUNDARY SHUD DESTABILIZE SIGNIFICANTLY THROUGH EARLY
AFTERNOON AND DEEP CONVECTION INCREASE... FIRST ACROSS THE
SOUTHERN FA AND THEN EXPANDING A BIT NORTHWARD FROM LATE AFTERNOON
INTO THE EVENING.
THIS NOW QUASI STATIONARY BOUNDARY SHUD REMAIN A FOCUS FOR
CONVECTION INTO MONDAY MORNING... SHIFTING SLOWLY NORTHWARD AND
WEAKENING THROUGHOUT THE DAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 355 AM CDT CDT SUN JUL 14 2013
MONDAY NIGHT AND TUESDAY...SOUTHWESTERLY FLOW ALOFT CONTINUES WITH
ANOTHER SHORTWAVE MOVING THROUGH SOUTHERN CANADA. A SFC TROUGH
DEVELOPING OVER THE NORTHERN ROCKIES ON MONDAY WILL HELP PUSH WARM
MOIST AIR BACK INTO THE CWA. HOWEVER...700MB TEMPS WILL ALSO BE ON
THE RISE SO WILL KEEP POPS IN THE 20 TO 30 PERCENT RANGE AS
CAPPING SHOULD MINIMIZE COVERAGE. THE UPPER SHORTWAVE OVER CANADA
MOVES BY TUESDAY AND SHOULD HELP PUSH ANOTHER WEAK FRONTAL
BOUNDARY INTO THE NORTHERN CWA.
TUESDAY NIGHT THROUGH SATURDAY...LONG WAVE UPPER LEVEL RIDGE
EXTENDS FROM THE OH VALLEY TO THE DESERT SOUTHWEST. BETWEEN DAY 5
AND DAY 7 EAST END OF UPPER RIDGE BEGINS TO SHIFT WEST AND SOUTH
AS UPPER TROUGH ROTATES INTO EASTERN CANADA AND THE NEW ENGLAND
STATES. GFS AND ECMWF WERE IN REASONABLE AGREEMENT AT THE
BEGINNING OF THE PERIOD. THE GFS BECOMES FASTER BY THE END OF THE
PERIOD. WILL USE A BLEND OF THE ECMWF AND GFS THIS PERIOD.
WILL TRIM BACK POPS ON THU NIGHT IN NORTHWEST ZONES AND TAKE OUT
PRECIP ON FRI.
TEMPS INCREASED A DEGREE OR TWO FOR WED...FRI AND SAT AND DECREASE A
DEGREE FOR THU FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 640 AM CDT SUN JUL 14 2013
QUASI STATIONARY SFC BOUNDARY STRETCHES ALONG AN ABR-FAR-BDE LINE.
NORTH OF THIS LINE...EXPECT PATCHY MVFR CIGS AND INCREASING
NORTHERLY BLAYER FLOW THROUGH THE MORNING. ALONG AND SOUTH OF
THIS BOUNDARY...SCT SHOWERS AND AN ISOLATED TSTM THROUGH THE
MORNING. SHOWERS AND EMBEDDED TSTMS SHUD BECOME MORE WIDEPSPREAD
THROUGH THE AFTERNOON SOUTH OF THIS BOUNDARY AND BEGIN TO PUSH
SLOWLY NORTHWARD IN THE LATE AFTERNOON AND EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...GUST
LONG TERM...HOPPES
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 AM EDT SUN JUL 14 2013
.SYNOPSIS...
A LARGE HIGH PRESSURE SYSTEM AT THE SURFACE AND ALOFT OVER
PENNSYLVANIA WILL TRACK SLOWLY WESTWARD INTO THE OHIO VALLEY THIS
WEEK. A COLD FRONT WILL LIKELY PUSH SOUTHWARD THRU THE REGION BY
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK INVERTED SFC TROF AND ASSOC PLUME OF ANOMALOUS PWATS LIFTING
NORTHWARD INTO CENTRAL PA EARLY THIS AM. RADAR LOOP AT 09Z SHOWS
JUST A FEW LIGHT SHOWERS/SPRINKLES ALONG THIS BOUNDARY WEST OF
HARRISBURG. RAP OUTPUT SHOWS THIS BAND OF HIGHER PWATS LIFTING TO
THE N TIER COUNTIES BY LATE AM. HOWEVER...GIVEN CURRENT RADAR
COVERAGE AND LACK OF LG SCALE FORCING...WILL NOT EXPLICITLY
MENTION PRECIP IN THE FCST THIS MORNING.
PLENTY OF LOW LVL MOISTURE AND A LINGERING LIGHT SE FLOW IS
PROMOTING INCREASING LOW CLOUDS/FOG EARLY THIS AM...AS EVIDENCED
BY 11-3.9U SATL LOOP. HOWEVER...AS SFC HIGH PRES SLIDES SOUTHWARD
OFF THE E COAST...FLOW ACROSS PA WILL SHIFT FROM SE TO SOUTH...BRINGING
BRIGHTER AND WARMER CONDS BY AFTN. ENS MEAN 925 TEMPS SUPPORT HIGH
TEMPS BTWN 85-90F.
LINGERING INVERTED SFC TROUGH AND ASSOC BAND OF ANOMALOUS PWATS
WILL LIE ALONG THE NY/PA BORDER THIS AFTN. DIURNAL HEATING OF THIS
MOIST...UNSTABLE AIR MASS COULD PRODUCE ISOLATED AFTN TSRA ACROSS
THE N MTNS LATE IN THE DAY. WEAK SHEAR INDICATES ANY STORMS THAT
FORM WILL BE OF THE PULSE VARIETY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
ANY ISOLD...DIURNALLY-DRIVEN EVENING TSRA ACROSS THE NORTH SHOULD DIE
OUT ARND SUNSET. WARM AND MUGGY CONDS EXPECTED THE REST OF THE NIGHT
WITH TEMPS RANGING FROM THE M60S OVR THE ALLEGHENIES...TO ARND 70F
IN THE SUSQ VALLEY.
DESPITE PRESENCE OF ANOMALOUS 5H HIGH PRES OVR PA...DIURNAL
HEATING OF MOIST AIR MASS SHOULD BE SUFFICIENT TO BREAK CAP AT
ARND 650MB...PRODUCING A FEW TSRA MONDAY AFTN. LINGERING SFC TROF AND
ASSOC BAND OF ANOMALOUS PWATS IS FCST TO LIE ACROSS CENTRAL
PA...RESULTING IN THE SCT PM CONVECTION ACROSS CENTRAL PA. GEFS
MEAN 8H TEMPS ARND 19C SHOULD TRANSLATE TO HIGH TEMPS FROM THE
U80S ACROSS THE ALLEGHENY PLATEAU...TO THE M90S IN THE SUSQ
VALLEY. THE COMBINATION OF HEAT AND HUMIDITY SHOULD PUSH HEAT
INDICES TO NR 100F ACROSS THE SUSQ VALLEY. WILL LET LATER SHIFTS
DECIDE WHETHER TO PULL THE TRIGGER ON A HEAT ADVISORY WITH BENEFIT
OF LATER GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH CONFIDENCE HEAT WAVE FOR CENTRAL PA MUCH OF NEXT WEEK...AS
ALL MED RANGE GUIDANCE SHOWING ANOMALOUS MID LVL HIGH PRESSURE
CENTER PARKED OVR THE OHIO VALLEY/MIDWEST WITH ANOMALOUS 8H TEMPS
OF NR 20C ACROSS PA.
THE DEVELOPING..DEEP LAYER NWRLY FLOW WOULD ORDINARILY BE QUITE
FAVORABLE FOR CONVECTION /EVEN A FEW MCS TYPE SYSTEMS/ MOVING
QUICKLY SE FROM THE UPPER GLAKES REGION AND INTO OUR AREA.
HOWEVER...IT APPEARS THAT EVEN THOUGH WE HAVE TREMENDOUS LLVL
MOISTURE...HEAT /WITH TEMPS IN THE L-MID 90S THROUGHOUT THE
VALLEYS/...AND ASSOCIATED PERIODS OF HIGH ML CAPE OF 2000-3000
J/KG...A STRONG MID LEVEL CAP /WITH 700 MB TEMPS AVERAGING 10-11C/
WILL PREVENT MUCH MORE THAN ISOLATED AND GENERALLY OROGRAPHICALLY
INDUCED MID TO LATE AFTERNOON SHOWERS AND THUNDERSTORMS FOR TUESDAY
THROUGH THURSDAY. PRACTICALLY ALL OF THE /ISOLATED/ CONVECTION
WILL BE IN THE 19-00Z TIMEFRAME EACH AFTERNOON/EVENING.
WILL STILL HAVE TO KEEP A CLOSE EYE JUST TO OUR NORTH AND NE FOR
THE POSSIBILITY OF SOME WEAKNESSES IN THIS CAP FROM A FEW WEAK
SHORT WAVES THAT MAY DROP TO DROP SE FROM NEW YORK STATE AND NIP
AWAY AT THE WWD MOVING UPPER HIGH AND MID LEVEL CAP.
ENOUGH LLVL CONVERGENCE AND INCREASED LG SCALE...DEEP LAYER UVVEL
MAY DEVELOP FRIDAY AFTERNOON /ALONG THE NRN EDGE OF THE
AFOREMENTIONED MID LEVEL CAP/ TO DEVELOP ONE OR MORE CLUSTERS OF
STRONG TO POTENTIALLY SEVERE TSRA JUST AHEAD OF A SFC CFRONT THAT
WILL EXTEND FROM THE WRN GLAKES...TO NEAR THE NORTH SHORE OF LAKE
ONTARIO BY 00Z SATURDAY. NRN PARTS OF THE CWA STAND THE GREATEST
CHC AT SEEING A TSRA LATE FRIDAY.
ALTHOUGH THE CURRENT MDL 8H TEMPS DON/T SUPPORT RECORD HIGHS...PERHAPS
THE MOST IMPORTANT ASPECT TO THIS UPCOMING HEAT WAVE WILL BE IT/S
DURATION...LASTING MONDAY THRU AT LEAST FRIDAY. DAILY HEAT INDICES
SHOULD TOP OUR NR 100F EACH DAY ACROSS THE SUSQ VALLEY...ALONG
WITH NIGHTTIME LOWS IN THE L70S.
BY NEXT WEEKEND...GEFS AND EC ENSEMBLE OUTPUT INDICATE A SFC
CFRONT WILL SAG SOUTH /WITH UPPER HEIGHTS LOWERING ACROSS THE
GLAKES AND NE REGION...AS A SERIES OF FAST MOVING...AND QUITE
POTENT SHORTWAVES RIDE THROUGH THE RIGHT ENTRANCE REGION OF THE
LARGER SCALE 110 KT 300 MB JET /SITUATED FROM LAKE SUPERIOR TO SRN
QUEBEC/. THIS SETUP WILL AFFORD THE CHC FOR A FEW ROUND OF STRONG
TO POTENTIALLY SVR TSRA /AND ONE OR MORE MCS FEATURES/.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A LARGE HIGH PRESSURE SYSTEM AT THE SURFACE AND ALOFT WILL BUILD
WESTWARD FROM THE ATLANTIC OCEAN AND PARK ITSELF OVER THE OHIO
VALLEY...BRINGING A PERIOD OF EXCELLENT FLYING CONDITIONS.
STRATOCU DECK MAINLY OVER EASTERN HALF ALREADY SHOWING SIGNS OF
BREAKING UP AT 12Z...AND THIS TREND SHOULD CONTINUE OVER THE NEXT
1-2 HOURS BRINGING A WIDESPREAD VFR DAY FOR ALL. THIS WILL BE THE
BEGINNING OF A SEVERAL DAY PERIOD WITH OVERALL EXCELLENT FLYING
CONDITIONS...WITH ONLY LOCALIZED LIGHT MORNING FOG AND SMALL
CHANCES FOR AN AFTERNOON TSTM EACH DAY. TODAY THAT LOW TSTM CHANCE
WILL BE ACROSS THE NORTHERN TIER IN VICINITY OF A WEAKENING TROUGH
JUST TO OUR NORTH AND IN THE LAURELS WITH DIFFERENTIAL
HEATING...BUT CHANCES TOO LOW TO MENTION IN KBFD-KJST TAFS.
OUTLOOK...
MON-THU...MAINLY VFR. DAILY LOCAL RESTRICTIONS POSS IN LIGHT
MORNING FOG AND ISO AFT TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...DEVOIR/FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
613 AM CDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR TODAY IS ON TEMPERATURES AND CLOUD COVER AS
UPPER LEVEL RIDGING PUSHES IN FROM THE EAST.
CURRENTLY...SOME SCATTERED CONVECTION HAS DEVELOPED ALONG THE
DEFORMATION BAND OF A WEAK 500MB TROUGH THAT EXTENDS FROM
NORTHWEST WISCONSIN DOWN INTO WESTERN IOWA. EXTENSIVE MID TO UPPER
LEVEL CLOUD COVER COMES WITH THIS BAND AND HAS BEEN SLOW TO SHIFT
TO THE WEST THIS MORNING. THE 14.06Z RAP 700-400MB RH FIELDS SEEM
TO HAVE A GOOD HANDLE ON THIS CLOUD COVER AND DOES CONTINUE TO
SHIFT THIS CLOUD DECK AND CONVECTION TO THE WEST QUICKLY THIS
MORNING.
HIGH TEMPERATURES FOR TODAY ARE THE NEXT QUESTION AS MUCH OF THE
REGION SHOULD HAVE FULL SUN. 14.06Z RAP AND 14.00Z NAM/GFS
SOUNDINGS INDICATE THAT THE HIGHEST POSSIBLE MIXING WOULD COME
FROM AROUND 875-850MB. WHEN MIXING DOWN A PARCEL FROM THAT LEVEL
OR LOWER...IT SHOWS THAT HIGHS TODAY HAVE A MAX OUT IN THE MID TO
UPPER 80S. MAY SEE SOME FAIR WEATHER CU FORMING BUT THE LOW LEVEL
MOISTURE DOES NOT REALLY START RAMPING UP UNTIL MONDAY...SO THINK
THAT IT WILL BE FEW AND FAR BETWEEN FOR ANY OF THAT DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR THE UPCOMING WEEK IS WITH THE CHANCES FOR RAIN
ALONG WITH DAILY TEMPERATURES.
DESPITE A MAINLY SUBSIDENT ENVIRONMENT MONDAY THROUGH
WEDNESDAY...INCREASING LOW LEVEL MOISTURE WILL LEAD TO A MORE HUMID AIR
MASS THAT WILL HAVE THE POTENTIAL OF PRODUCING SOME VERY ISOLATED
SHOWERS AND THUNDERSTORMS. CONFIDENCE IS NOT VERY HIGH WITH
WHETHER THEY WILL EVEN DEVELOP BASED ON THE LACK OF A FORCING
MECHANISM...BUT GUIDANCE HAS BEEN CONSISTENT WITH SHOWING SOME
PRECIPITATION FORMING IN THE AFTERNOON DURING DIURNAL PEAK
HEATING. HAVE DECIDED TO HONOR THIS WITH SOME 20 PERCENT CHANCES
OF PRECIPITATION MONDAY/TUESDAY/WEDNESDAY AFTERNOON AS A RESULT.
ANY DEEP LAYER SHEAR IS NON-EXISTENT...SO THIS WILL BE
PULSEY/CELLULAR CONVECTION THAT IS BRIEF AND NON- SEVERE.
THE HIGHER CHANCES FOR PRECIPITATION WILL COME LATER IN THE WEEK
AS A COLD FRONT SAGS SOUTH FROM ALONG THE US/CANADIAN BORDER. THE
14.00Z GFS/ECMWF/GEM ALL ANGLE THIS FRONT FROM NEAR FARGO TO THE
EAST TOWARD NORTH CENTRAL WISCONSIN ON THURSDAY WITH CONVECTION
EXPECTED TO DEVELOP ALONG THIS REGION. THE FRONT IS THEN EXPECTED
TO GET A PUSH TO THE SOUTH FRIDAY INTO SATURDAY WITH THE GFS BEING
MUCH MORE WIDESPREAD ON ITS PRECIPITATION WHEN COMPARED TO THE
LATEST ECMWF RUN. HOWEVER...THE TIMING OF THIS FROPA STILL LOOKS
FAIRLY CONSISTENT BETWEEN THESE MODELS...SO HAVE SOME ABOVE
AVERAGE CONFIDENCE IN THE TIMING OF THE HIGHEST PROBABILITIES OF
PRECIPITATION BASED ON THIS FROPA.
LOW LEVEL TEMPERATURES APPEAR TO CLIMB GRADUALLY THROUGH THE WEEK
WITH 850MB TEMPERATURES JUMPING FROM AROUND +16C TODAY TO +20C BY
THURSDAY NIGHT AND 925MB TEMPERATURES GOING FROM +21C TODAY TO
+27C BY THURSDAY NIGHT. WITH MAINLY SUNNY SKIES...TEMPERATURES
SHOULD BE ABLE TO REACH 90F TUESDAY THROUGH THURSDAY AND PERHAPS
FRIDAY IF THE FRONT TAKES LONGER TO GET THROUGH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
613 AM CDT SUN JUL 14 2013
GENERALLY GOOD VFR CONDITIONS EXPECTED TODAY/TONIGHT AS SEASONABLY
DRY HIGH PRESSURE LOCATED OVER THE GREAT LAKES REMAINS IN CONTROL OF
THE AREA/S WEATHER. WITH PERSISTENT SOUTHERLY LOW LEVEL FLOW...LOWER
LEVEL MOISTURE WILL GRADUALLY INCREASE. DIURNAL WARMING IS EXPECTED
TO PRODUCE SCT 4K-5K FT CUMULUS FOR THE AFTERNOON INTO EARLY EVENING
HOURS...OTHERWISE ANY CLOUDS LOOKING TO BE ABOVE 10K FT THRU TONIGHT.
LIGHT WINDS AND MOSTLY CLEAR SKIES TONIGHT COUPLED WITH THE
INCREASING BOUNDARY LAYER MOISTURE RAISE CONCERNS FOR SOME BR IN THE
09-13Z TIME-FRAME. WITH THE CENTER OF THE HIGH WELL OFF TO THE EAST
OF THE AREA AND SOME PERSISTENT BUT LIGHT SOUTH-SOUTHEAST GRADIENT
WINDS TONIGHT...LEFT ANY MENTION OF MVFR BR OUT OF THE END OF THE
TAF PERIOD FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN JUL 14 2013
.SYNOPSIS...
A DEEP MONSOON AIRMASS WILL REMAIN OVER THE EASTERN PORTION OF THE
REGION THIS WEEK. THE THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL CONTINUE...MAINLY OVER THE CENTRAL AND EASTERN
ARIZONA MOUNTAINS. AFTERNOON TEMPERATURES NEAR OR SLIGHTLY ABOVE
NORMAL ARE EXPECTED THROUGH MONDAY AND THEN COOLING CONSIDERABLY BY
THE MIDDLE PART OF THE WEEK. MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTHERN ARIZONA STARTING
TUESDAY.
&&
.DISCUSSION...
12Z SOUNDING FROM PHOENIX INDICATED APPROXIMATELY 500 J/KG CAPE
ABOVE 700MB THIS MORNING...SURE ENOUGH THERE WERE A FEW ELEVATED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA EARLIER TODAY /MAINLY
ACROSS SW AZ AND SE CA/. MOST OF THIS ACTIVITY HAS SINCE DISSIPATED
WITH LITTLE PRECIP LEFT ON THE RADAR AS OF 16Z. LINGERING CLOUD
COVER FROM THESE STORMS SURE TOOK AWAY SEVERAL HOURS OF GOOD
RADIATIONAL COOLING...MOST DESERT LOCATIONS ONLY DROPPED INTO THE
UPPER 80S/LOWER 90S THIS MORNING. NEEDLESS TO SAY...IT WAS A WARM
START TO THE MORNING.
FORECAST FOR LATER TODAY REMAINS LARGELY UNCHANGED...AS ALL HI-RES
MODELS AND LATEST HRRR MODEL INDICATE STORMS SHOULD BE CONFINED TO
THE RIM AND POINTS EAST OF PHOENIX. CURRENT FORECAST ONLY CALLS FOR
AN ISOLATED SHOWER OR THUNDERSTORM ACROSS THE DESERTS AND THIS STILL
SEEMS APPROPRIATE GIVEN 12Z MODEL DATA. HIGHER POPS /AROUND 30
PERCENT/ WILL REMAIN IN PLACE EAST OF PHOENIX...NO REAL CHANGES
NECESSARY.
MADE MINOR ADJUSTMENTS TO MAX TEMPS BASED ON TRENDS THROUGH 16Z.
GIVEN THE WARM START...I ADDED 1-2 DEGREES TO THE HIGHS ACROSS MOST
OF THE FORECAST AREA. ALREADY PUSHING 98 AT KPHX...HIGHS 105-110
SEEM REASONABLE GIVEN THE WARM START AND SLIGHTLY LOWER DEWPOINTS
THAN THIS TIME SATURDAY.
&&
.PREVIOUS DISCUSSION...
EVEN SMALLER CHANCES FOR MONSOON STORMS ARE EXPECTED FOR MONDAY AS
THE FULL EXTENT OF THE QUASI DRY AIR IS FELT. ALL STORMS SHOULD BE
CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. ALTHOUGH
MONDAY WILL BE FAIRLY QUIET...THE RETROGRADING UPPER LOW FROM THE
OHIO RIVER VALLEY WILL BE NEARING THE DESERT SOUTHWEST. ALL
OPERATIONAL MODELS AND ENSEMBLES INDICATE IT WILL MOVE INTO NEW
MEXICO AND ARIZONA BY MONDAY NIGHT INTO TUESDAY. HARD TO IMAGINE AN
UPPER LOW RETROGRADING TO THAT DEGREE...BUT ITS BEEN ADVERTISED FOR
SEVERAL DAYS NOW AND WV IMAGERY CLEARLY DEPICTING THE SOUTHWESTERLY
MOVEMENT OF THE LOW.
THE UPPER LOW WILL USHER IN EVEN HIGHER MIXING RATIOS MONDAY INTO
TUESDAY. SOME OF OUR BIGGEST CONVECTIVE EVENTS CLIMATOLOGICALLY HAVE
BEEN EASTERLY WAVES COMING IN FROM THE FOUR CORNERS. CHANCE POPS FOR
MONDAY AND MONDAY NIGHT EAST OF PHOENIX STILL SEEMS REASONABLE WITH
CHANCE POPS TUESDAY ACROSS THE METRO PHOENIX AREA AND LIKELY POPS TO
THE EAST. THERE ARE STILL SOME MODEL DIFFERENCES IN THE TRACK AND
THE POSITIONING OF THE LOW AS IT NEARS AND MOVES THROUGH THE AREA SO
IT IS TOUGH TO SAY WHICH DAY WILL BE THE BUSIEST WEATHER DAY THIS
WEEK. TEMPERATURE FORECAST IS ALSO ON THE DIFFICULT SIDE WITH A
LARGE DISTRIBUTION OF TEMPERATURES AMONG GUIDANCE. HAVE TRENDED
COOLER FROM PHOENIX EASTWARD TUESDAY THROUGH THE END OF THE WEEK. IT
IS CONCEIVABLE WE COULD HAVE A DAY SOMEWHERE IN THE TUESDAY TO
FRIDAY TIME FRAME WHERE HIGHS DON/T MAKE IT ABOVE 90 IN SOME LOWER
DESERT LOCATIONS. THE QUESTION OF HOW LONG THE LOW WILL REMAIN OVER
THE AREA WILL DETERMINE RAIN CHANCES AND TEMPERATURES AFTER
WEDNESDAY. AT THIS POINT...IT IS TOO EARLY TO TELL HOW LONG THIS LOW
WILL END UP INFLUENCING OUR WEATHER IN THE COMING WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ONLY PERIODIC HIGH/MID CLOUDS ARE EXPECTED TO SPREAD OVER CNTRL
ARIZONA TERMINALS THROUGH MONDAY MORNING. SHRA/TSRA SHOULD REMAIN
WELL TO THE NORTH AND EAST OF THE PHOENIX AREA...WITH LITTLE CHANCE
OF ANY OUTFLOWS REACHING THE SITES. OTHERWISE...LARGELY LIGHT AND
VARIABLE WINDS SHOULD BECOME PREDOMINATELY W/SW BY LATE
MORNING...AND LIKELY PERSISTING AS SUCH WELL INTO THE EVENING HOURS.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
MID/HIGH CLOUDS WILL PERIODICALLY COVER SERN CALIFORNIA
TERMINALS...WITH NO STORM ACTIVITY OR IMPACTS EXPECTED. WINDS WILL
GENERALLY REMAIN BELOW 10 KT AND RETAIN A BASE SOUTHERLY COMPONENT
THROUGH MONDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH FRIDAY...
A SEASONABLY STRONG UPPER LOW WILL BE MOVE INTO THE REGION FROM THE
EAST...AND BECOME THE TRIGGER FOR AN ACTIVE PERIOD OF SHOWERS AND
THUNDERSTORMS. MOST LOCATIONS IN ARIZONA WILL EXPERIENCE A GOOD
CHANCE FOR WETTING RAINS...WITH SOMEWHAT LESSER CHANCES OVER
SOUTHEAST CALIFORNIA. MINIMUM HUMIDITIES WILL BE HIGHER THAN
NORMAL...IN THE 20-30 RANGE ACROSS THE LOWER DESERTS...AND 40
PERCENT OR HIGHER OVER THE HIGHER TERRAIN...WITH EXCELLENT OVERNIGHT
RECOVERY. WINDS WILL OBTAIN MORE OF A PERSISTENT EASTERLY DIRECTION
THROUGH MUCH OF THE PERIOD...WITH OCCASIONAL LOCALLY HIGHER GUSTS IN
ASSOCIATION WITH THUNDERSTORM OUTFLOW BOUNDARIES.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/KUHLMAN
AVIATION...MO
FIRE WEATHER...MO/PERCHA
AREA FORECAST DISCUSSION
NWS MIAMI FL
241 PM EDT SUN JUL 14 2013
.DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY, THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS.
BY THE MIDDLE OF THE WEEK THE AREA OF HIGH PRESSURE OVER NORTH
AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH FLORIDA
WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD ON THE
SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT CHANGES
IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR TRAVEL
AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC.
THE INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A
WEAKNESS IN THE HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY
OVER THE BAHAMA ISLANDS. THIS WILL BRING A BRIEF PERIOD OF
NORTHEASTERLY WINDS ON MONDAY MORNING. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
&&
.AVIATION...
THE PERIOD BEGINS WITH MAINLY LINGERING LIGHT RAIN OVER THE APF
TERMINAL AS MOST OF THE HEAVIER ACTIVITY HAS SHIFTED INLAND FROM
COLLIER TO GLADES COUNTY. THE LATEST HRRR MODEL REFLECTIVITY SHOW
THE BULK OF THE AFTERNOON ACTIVITY CONTINUING TO DEVELOP OVER THE
INTERIOR AND NORTHERN AREAS THROUGH THE REMAINDER OF THE AFTERNOON
HOURS. FOR NOW...WE WILL CONTINUE TO CARRY VCTS ALONG THE EAST COAST
AND UPDATE AS CONDITIONS EVOLVE. THIS ACTIVITY SHOULD WEAKEN AND
TREND DOWN THROUGH THE OVERNIGHT HOURS TONIGHT WITH LIGHT EASTERLY
FLOW RETURNING ACROSS THE AREA. LIGHT TO MODERATE EASTERLY FLOW ON
MONDAY SHOULD TRANSLATE TO THE AFTERNOON ACTIVITY SETTING UP INLAND
OF THE EAST COAST ACROSS THE INTERIOR AND GULF COAST THROUGH THE
AFTERNOON HOURS.
&&
.MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST TO
SOUTHEAST WIND IS ANTICIPATED THROUGH THE MIDDLE OF NEXT WEEK.
&&
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 76 88 / 40 20 10 30
FORT LAUDERDALE 75 88 79 89 / 40 30 20 30
MIAMI 74 89 78 89 / 40 30 20 30
NAPLES 71 88 73 92 / 40 50 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1244 PM CDT SUN JUL 14 2013
.DISCUSSION...
ISSUED 1007 AM CDT SUN JUL 14 2013
NO CHANGES ANTICIPATED TO THE CURRENT FORECAST. UPPER LOW THAT
BROUGHT WIDELY SCATTERED THUNDERSTORMS TO SOUTHERN ILLINOIS
YESTERDAY HAS NOW SHIFTED INTO EASTERN KANSAS. SOUTHEASTERLY FLOW
ON ITS BACKSIDE IS BRINGING INCREASING MOISTURE INTO THE REGION
THIS MORNING...AS EVIDENCED BY UPSTREAM 850MB DEWPOINTS OF 13C AT
BOTH KILN AND KOHX. DESPITE LACK OF GOOD UPPER-LEVEL
SUPPORT...INCREASING MOISTURE AND POSSIBLE WEAKNESS/TROUGH AXIS IN
PRESSURE FIELD MAY SUPPORT ISOLATED CONVECTION LATER THIS
AFTERNOON. 13Z HRRR SHOWS THIS OCCURRING ACROSS MAINLY THE E/SE
KILX CWA AFTER 21Z. WILL CONTINUE TO MENTION ISOLATED THUNDER IN
THE FORECAST ACCORDINGLY...ALTHOUGH THE MAJORITY OF THE AREA WILL
REMAIN WARM AND DRY TODAY.
&&
.AVIATION...
ISSUED 1244 PM CDT SUN JUL 14 2013
SCT DIURNAL CU WILL DEVELOP ACROSS THE AREA THIS AFTERNOON...THEN
WILL FADE AWAY BY SUNSET. WITH CLEAR SKIES AND LIGHT WINDS
EXPECTED OVERNIGHT...PATCHY FOG WILL BE A STRONG POSSIBILITY AS
SURFACE DEWPOINTS HOVER IN THE UPPER 60S. FORECAST SOUNDINGS AND
NUMERIC GUIDANCE BOTH SUPPORT MINOR VISBY RESTRICTIONS...SO HAVE
GONE WITH PREVAILING 4SM AFTER 06Z. ONCE EARLY MORNING FOG
DISSIPATES...NEGATIVE CU-RULE SUGGESTS SCT-BKN CU DEVELOPING FROM
LATE MONDAY MORNING THROUGH THE AFTERNOON. WINDS WILL REMAIN LIGHT
THROUGH THE ENTIRE PERIOD...GENERALLY FROM THE SE AT LESS THAN
10KT.
BARNES
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT SUN JUL 14 2013
SHORT TERM...TODAY THROUGH THURSDAY NIGHT
00Z MODELS ARE IN FAIR AGREEMENT THROUGH MID WEEK AS A HOT AND
HUMID WEEK IS AHEAD FOR CENTRAL AND SOUTHEAST IL. THIS DUE TO
STRONG 597 DM 500 MB HIGH PRESSURE RIDGE OFF THE SOUTHERN NEW
ENGLAND COAST INTO PA/NJ THAT RETROGRADES WESTWARD INTO THE OHIO
VALLEY AND SOUTHERN GREAT LAKES BY TUE AND STAYS NEAR IL AS IT
SLOWLY WEAKENS AND SHIFTS SOUTHWARD LATER THIS WEEK ALLOWING A
FRONTAL BOUNDARY TO SAG SOUTHWARD OVER THE REGION NEXT WEEKEND.
THIS BOUNDARY WILL BRING A BETTER CHANCE OF SHOWERS/THUNDERSTORMS
NEXT WEEKEND.
579 DM 500 MB LOW PRESSURE OVER SE MO MOVE QUICKLY WSW INTO
EASTERN OK BY SUNSET TODAY WHILE 597 DM 500 HIGH PRESSURE RIDGE
SHIFTS WESTWARD ACROSS PA AND INTO THE EASTERN GREAT LAKES REGION.
NOT MUCH LIFTING MECHISMS AROUND IL TODAY BUT INCREASING DEEPER
GULF MOISTURE CONTINUES TO STREAM NW INTO IL WITH PRECIPITABLE
WATER VALUES RISING TO 1.5 TO 2 INCHES THIS AFTERNOON AND HIGHEST
IN SE IL. AIRMASS GETS UNSTABLE THIS AFTERNOON WITH CAPES OF 1000
TO 2000 J/KG SE OF THE IL RIVER AND THIS SHOULD ALLOW ISOLATED
SHOWERS AND THUNDERSTORMS TO DEVELOP FROM MID AFTERNOON INTO EARLY
EVENING UNTIL SUNSET FROM I-72 SOUTH. SUNNY SKIES TO BECOME PARTLY
TO MOSTLY SUNNY IN AFTERNOON WITH HIGHS IN THE MID TO UPPER 80S.
DEWPOINTS IN THE LOW TO MID 60S TO RISE INTO THE UPPER 60S TO NEAR
70F BY AFTERNOON.
HAVE A SLIGHT CHANCE OF CONVECTION UNTIL MID EVENING FROM I-72
SOUTH THEN DRY REST OF TONIGHT WITH LOWS AROUND 70F. HAVE ISOLATED
CONVECTION DEVELOPING AGAIN DURING MONDAY AFTERNOON AND OVER IL
RIVER VALLEY TOO AS UNSTABLE AIRMASS SPREADS FURTHER NW. VERY WARM
AND HUMID WITH HIGHS IN THE UPPER 80S TO NEAR 90F MONDAY WITH
DEWPOINTS IN THE LOWER 70S. AFTERNOON HEAT INDICES IN MID TO UPPER
90S AND A FEW SPOTS IN SE IL BY WABASH RIVER NEARING 100F.
STRONG UPPER LEVEL RIDGE NEARS IL DURING MIDDLE OF THE WEEK
BRINGING HOT AND HUMID CONDITIONS WITH HIGHS IN THE LOWER 90S TUE
THROUGH FRI AND AFTERNOON HEAT INDICES OF 98 TO 105F. HAVE
ISOLATED CONVECTION POSSIBLE EACH AFTERNOON AND EARLY EVENING DURING
THE WORK WEEK AND COVERAGE SHOULD BE LIMITED WITH STRONG UPPER
LEVEL RIDGE NEARBY PROVIDING A CAP. BUT HAVE TROPICAL AIRMASS IN
PLACE WITH DEWPOINTS IN THE LOW TO MID 70S.
LONG TERM...FRIDAY THROUGH SUNDAY
MODELS HAVE TRENDED SLOWER WITH FRONTAL BOUNDARY PUSHING SOUTHWARD
THROUGH IL DURING THIS WEEKEND AS UPPER LEVEL RIDGE SHIFTS BACK
SOUTH AND WEAKENS. BEST CHANCES OF CONVECTION STILL APPEARS NORTH
OF CENTRAL IL FRIDAY AND THIS SHIFTS SOUTHWARD INTO CENTRAL IL SAT
AND BEST CHANCES SHIFT INTO SOUTHEAST IL BY SUNDAY. TEMPS TO
GRADUALLY COOL OFF CURING THE WEEKEND WITH HIGHS IN THE LOW TO MID
80S SUNDAY BUT STAYING RATHER HUMID YET WITH DEWPOINTS IN THE
UPPER 60S AND LOWER 70S.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
203 PM MDT SUN JUL 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 125 PM MDT SUN JUL 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 579DM CLOSED LOW CENTERED
OVER NORTHEAST OKLAHOMA WITH STRONG PV HEIGHT ANOMALY IN PLACE OVER
SOUTHEAST KS. A 599DM RIDGE IS IN PLACE OVER THE NORTHEAST US WITH
AXIS EXTENDING NORTH OF CLOSED LOW INTO THE UPPER MISSISSIPPI VALLEY.
WITH GOOD MOISTURE/INSTABILITY IN PLACE AND SEVERAL WEAK CONVERGENT
AREAS WE ARE ALREADY SEEING THUNDERSTORMS DEVELOPING ALONG SEVERAL
WEAK CONVERGENT AREAS IN OUR CWA. AS LARGE SCALE FORCING INCREASES
AND THE MAIN MOISTURE PLUME MOVES OVER OUR CWA I EXPECT THUNDERSTORM
COVERAGE TO INCREASE. WHAT COULD BE DESCRIBED AS A COLD FRONT WILL
MOVE INTO THE CWA FROM THE SOUTHEAST THIS AFTERNOON AHEAD OF COLD
POOL ASSOCIATED WITH STRONG UPPER LOW. THUNDERSTORMS WILL INCREASE
IN COVERAGE AS THIS BOUNDARY MOVES NORTHWEST WITH BEST FORCING
CURRENTLY ADVERTISED IN THE 21-00Z TIME FRAME ALONG THE KS/CO BORDER
WHERE MOST GUIDANCE IS SHOWING VERY HIGH QPF VALUES. LATEST GFS IS A
LITTLE FURTHER EAST...HOWEVER SHORT RANGE GUIDANCE (RUC/HRRR)
CONTINUE TO SUPPORT THE NAM SOLUTION FURTHER WEST ALONG COLORADO
STATE LINE.
A VERY MOIST AIR MASS IS IN PLACE OVER THE CWA WITH LATEST RAP
ANALYSIS INDICATING PWAT VALUES IN EXCESS OF 1.5 INCHES AND AS HIGH
AS 1.8 INCHES IN NORTHEAST PARTS OF THE CWA. WHILE NOT UNHEARD OF
THIS IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. SB/ML CAPE VALUES
HAVE INCREASED TO NEAR 2000 J/KG ACROSS THE NORTHEAST CWA AND THE
MAIN INSTABILITY AXIS SHOULD CONTINUE TO SPREAD SOUTH AND WEST THIS
AFTERNOON. SHEAR PROFILES ARE VERY WEAK...SO ANY SEVERE THREAT SHOULD
BE TIED TO WIND/HAIL ASSOCIATED WITH PULSE TYPE THUNDERSTORMS. STORM
MOTION WILL GENERALLY BE IN THE 5-15KT RANGE ACROSS THE AREA AND
THERE WILL BE THE POTENTIAL FOR BACK BUILDING AND SLOW PROPAGATION
ALONG THE BOUNDARY OVER OUR WESTERN CWA. WITH HIGH PRECIP RATES AND
SLOW MOVING (POSSIBLY TRAINING) THUNDERSTORM WE COULD SEE AN
ELEVATED THREAT FOR FLASH FLOODING. DESPITE OVERALL SHOWER AND
THUNDERSTORM COVERAGE LIKELY HIGH I AM NOT CONFIDENT THE FLASH FLOOD
THREAT WILL BE WIDESPREAD ENOUGH TO ISSUE A WATCH AT THIS TIME.
ACTIVITY SHOULD COME TO AN END QUICKLY FROM THE EAST TO THE WEST
THIS EVENING AS STRONG SUBSIDENCE BUILDS IN FROM THE NORTHEAST
ASSOCIATED WITH RIDGE BUILDING EAST BEHIND TROUGH. WITH LINGERING
CONVERGENCE ACROSS EASTERN COLORADO AND MOIST UPSLOPE WE COULD SEE A
FEW LINGERING SHOWERS/THUNDERSTORMS THROUGH 12Z WITH PATCHY FOG
POSSIBLY DEVELOPING IN THE 09Z-12Z TIME FRAME.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 158 PM MDT SUN JUL 14 2013
MONDAY MORNING MAY START OUT WITH SOME FOG OVER THE SOUTHERN AND
WESTERN PARTS OF THE AREA. ANY FOG THAT DEVELOPS SHOULD CLEAR OUT
BY MID MORNING. THE UPPER LEVEL LOW PRESSURE THAT BROUGHT RAINFALL
TO THE TRI-STATE AREA WILL CONTINUE TO MOVE SOUTH. LATE MONDAY
AFTERNOON INTO EARLY MONDAY EVENING THERE WILL BE A BAND OF MID
LEVEL LIFT THAT WILL MOVE ACROSS THE FAR SOUTHERN PART OF THE AREA.
THERE WILL BE AMBLE MOISTURE TO WORK...BUT THE LIMITING FACTOR WILL
BE THE STRENGTHEN OF THE LIFT AND THE SMALL AMOUNT OF INSTABILITY
AVAILABLE. AT THIS TIME THERE APPEARS TO BE ENOUGH LIFT AND
INSTABILITY THAT AN ISOLATED STORM CANNOT BE RULED OUT...SO WILL
KEEP THE SLIGHT CHANCES IN THE FORECAST BUT CONFINE THEM TO THE LATE
AFTERNOON AND EARLY EVENING.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA.
SOUNDINGS OVER EAST CENTRAL COLORADO SHOW SOME INSTABILITY TO WORK
WITH AND LITTLE CIHN DURING THE AFTERNOON...BUT WITH NO SURFACE
CONVERGENCE OR UPPER LEVEL LIFT TO TRIGGER STORMS WILL KEEP THE DAY
DRY.
WEDNESDAY THROUGH SUNDAY AN UPPER LEVEL RIDGE WILL MOVE OVER THE
PLAINS THEN BECOME ESTABLISHED OVER THE ROCKIES. TOWARD THE END OF
THE WEEK THE UPPER LEVEL FLOW WILL STRENGTHEN AND BECOME NORTHWEST.
MODELS HAVE FLATTENED OUT THE SHORT WAVE TROUGH THAT WOULD MOVE OVER
THE AREA DURING THE WEEKEND. THE STRENGTH OF THE COLD FRONT HAS
ALSO DECREASED...WITH MODELS WASHING IT OUT ON SATURDAY OVER THE
AREA. HOWEVER MODELS STILL HAVE A SURFACE TROUGH/WEAK COLD FRONT
OVER THE AREA FOR THE WEEKEND. WITH NORTHWEST UPPER LEVEL FLOW OVER
THE AREA THERE IS STILL A POSSIBILITY FOR STORMS TO
DEVELOP...ALTHOUGH NOT AS GOOD AS PREVIOUSLY THOUGHT.
HIGH TEMPERATURES FOR THE PERIOD WILL GRADUALLY WARM TO ABOVE NORMAL
BY THE END OF THE WEEK AS THE UPPER LEVEL RIDGE BUILDS OVER THE
AREA. WITH LITTLE CHANGE IN THE AIR MASS BY THE END OF THE
WEEK...HIGHS WILL LARGELY REMAIN UNCHANGED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1123 AM MDT SUN JUL 14 2013
AS UPPER LEVEL SYSTEM MOVE WEST AND FORCING INCREASING
THUNDERSTORMS WILL INCREASE IN COVERAGE WITH BEST CHANCES AT KGLD
TERMINAL. HEAVY RAIN COULD DECREASE VIS TO IFR/MVFR CATEGORIES AT
KGLD...HOWEVER AXIS OF HEAVIEST RAIN MAY BE FURTHER WEST AND
CONFIDENCE WASNT THERE TO LOWER CONDITIONS BELOW VFR AT EITHER
TERMINAL. THUNDERSTORM ACTIVITY SHOULD TRANSITION WESTWARD WITH
HIGH PRESSURE BUILDING INT FROM THE NORTHEAST THIS EVENING. WINDS
ARE GOING TO BE ERRATIC EARLY IN THE PERIOD WITH SURFACE TROUGH
STILL IN PLACE...THOUGH EVENTUALLY THEY SHOULD SHIFT TO THE
NORTHEAST AND THEN SOUTHEAST AROUND 12KT AS FRONT MOVES OVER BOTH
TERMINALS THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
126 PM MDT SUN JUL 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 125 PM MDT SUN JUL 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 579DM CLOSED LOW CENTERED
OVER NORTHEAST OKLAHOMA WITH STRONG PV HEIGHT ANOMALY IN PLACE OVER
SOUTHEAST KS. A 599DM RIDGE IS IN PLACE OVER THE NORTHEAST US WITH
AXIS EXTENDING NORTH OF CLOSED LOW INTO THE UPPER MISSISSIPPI VALLEY.
WITH GOOD MOISTURE/INSTABILITY IN PLACE AND SEVERAL WEAK CONVERGENT
AREAS WE ARE ALREADY SEEING THUNDERSTORMS DEVELOPING ALONG SEVERAL
WEAK CONVERGENT AREAS IN OUR CWA. AS LARGE SCALE FORCING INCREASES
AND THE MAIN MOISTURE PLUME MOVES OVER OUR CWA I EXPECT THUNDERSTORM
COVERAGE TO INCREASE. WHAT COULD BE DESCRIBED AS A COLD FRONT WILL
MOVE INTO THE CWA FROM THE SOUTHEAST THIS AFTERNOON AHEAD OF COLD
POOL ASSOCIATED WITH STRONG UPPER LOW. THUNDERSTORMS WILL INCREASE
IN COVERAGE AS THIS BOUNDARY MOVES NORTHWEST WITH BEST FORCING
CURRENTLY ADVERTISED IN THE 21-00Z TIME FRAME ALONG THE KS/CO BORDER
WHERE MOST GUIDANCE IS SHOWING VERY HIGH QPF VALUES. LATEST GFS IS A
LITTLE FURTHER EAST...HOWEVER SHORT RANGE GUIDANCE (RUC/HRRR)
CONTINUE TO SUPPORT THE NAM SOLUTION FURTHER WEST ALONG COLORADO
STATE LINE.
A VERY MOIST AIRMASS IS IN PLACE OVER THE CWA WITH LATEST RAP
ANALYSIS INDICATING PWAT VALUES IN EXCESS OF 1.5 INCHES AND AS HIGH
AS 1.8 INCHES IN NORTHEAST PARTS OF THE CWA. WHILE NOT UNHEARD OF
THIS IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. SB/ML CAPE VALUES
HAVE INCREASED TO NEAR 2000 J/KG ACROSS THE NORTHEAST CWA AND THE
MAIN INSTABILITY AXIS SHOULD CONTINUE TO SPREAD SOUTH AND WEST THIS
AFTERNOON. SHEAR PROFILES ARE VERY WEAK...SO ANY SEVERE THREAT SHOULD
BE TIED TO WIND/HAIL ASSOCIATED WITH PULSE TYPE THUNDERSTORMS. STORM
MOTION WILL GENERALLY BE IN THE 5-15KT RANGE ACROSS THE AREA AND
THERE WILL BE THE POTENTIAL FOR BACK BUILDING AND SLOW PROPAGATION
ALONG THE BOUNDARY OVER OUR WESTERN CWA. WITH HIGH PRECIP RATES AND
SLOW MOVING (POSSIBLY TRAINING) THUNDERSTORM WE COULD SEE AN
ELEVATED THREAT FOR FLASH FLOODING. DESPITE OVERALL SHOWER AND
THUNDERSTORM COVERAGE LIKELY HIGH I AM NOT CONFIDENT THE FLASH FLOOD
THREAT WILL BE WIDESPREAD ENOUGH TO ISSUE A WATCH AT THIS TIME.
ACTIVITY SHOULD COME TO AN END QUICKLY FROM THE EAST TO THE WEST
THIS EVENING AS STRONG SUBSIDENCE BUILDS IN FROM THE NORTHEAST
ASSOCIATED WITH RIDGE BUILDING EAST BEHIND TROUGH. WITH LINGERING
CONVERGENCE ACROSS EASTERN COLORADO AND MOIST UPSLOPE WE COULD SEE A
FEW LINGERING SHOWERS/THUNDERSTORMS THROUGH 12Z WITH PATCHY FOG
POSSIBLY DEVELOPING IN THE 09Z-12Z TIME FRAME.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 431 AM MDT SUN JUL 14 2013
SECOND HALF OF THE WORK WEEK LOOKS DRY AND WARMER AS A WEAK BUT
BROAD UPPER LEVEL RIDGE SITS ACROSS THE EASTERN TWO THIRDS OF THE
CONUS. BREEZY SOUTHERLY WINDS ON WED AND THURS WILL KEEP TEMPS AT OR
ABOVE NORMAL /LOW TO MID 90S/. NO PRECIP IS EXPECTED AND RELATIVE
HUMIDITY WILL REMAIN WELL ABOVE FIRE WX CRITERIA.
TOWARDS THE WEEKEND THE STORY CHANGES AS THE RIDGE IN THE EAST
BREAKS DOWN AND A SMALL BUT RELATIVELY STRONG VORT MAX MOVES ACROSS
NORTHERN COLORADO AND INTO THE CENTRAL HIGH PLAINS...THOUGH GUIDANCE
IS NOT IN VERY GOOD AGREEMENT ON THE PLACEMENT OF THE SYNOPTIC
FORCING. STILL...FEEL THERE IS GOOD ENOUGH AGREEMENT ON THIS AS AN
ASSOCIATED COLD FRONT COULD HELP WITH STORM DEVELOPMENT. MOISTURE
WILL BE NO PROBLEM AS SOUTH/SOUTHWESTERLY WINDS ALOFT WILL HELP TO
ADVECT MOIST MONSOONAL AIR INTO THE REGION...AND IN FACT ON SATURDAY
NIGHT GFS HAS PWATS OF OVER 1.50 INCHES. TEMPS WILL BE WARMEST ON
FRIDAY IN THE MID TO UPPER 90S...DROPPING TO UPPER 80S/LOW 90S ON
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1123 AM MDT SUN JUL 14 2013
AS UPPER LEVEL SYSTEM MOVE WEST AND FORCING INCREASING
THUNDERSTORMS WILL INCREASE IN COVERAGE WITH BEST CHANCES AT KGLD
TERMINAL. HEAVY RAIN COULD DECREASE VIS TO IFR/MVFR CATEGORIES AT
KGLD...HOWEVER AXIS OF HEAVIEST RAIN MAY BE FURTHER WEST AND
CONFIDENCE WASNT THERE TO LOWER CONDITIONS BELOW VFR AT EITHER
TERMINAL. THUNDERSTORM ACTIVITY SHOULD TRANSITION WESTWARD WITH
HIGH PRESSURE BUILDING INT FROM THE NORTHEAST THIS EVENING. WINDS
ARE GOING TO BE ERRATIC EARLY IN THE PERIOD WITH SURFACE TROUGH
STILL IN PLACE...THOUGH EVENTUALLY THEY SHOULD SHIFT TO THE
NORTHEAST AND THEN SOUTHEAST AROUND 12KT AS FRONT MOVES OVER BOTH
TERMINALS THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1123 AM MDT SUN JUL 14 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 431 AM MDT SUN JUL 14 2013
MAIN FORECAST CONCERNS WILL PRECIPITATION COVERAGE AND AMOUNTS
THROUGH TONIGHT IT WHAT LOOKS TO BE A COMPLICATED FORECAST DURING
THIS TIME. SATELLITE CONTINUING TO SHOW AN AMPLIFIED AND COMPLICATED
UPPER FLOW PATTERN FROM THE CENTRAL PACIFIC INTO EASTERN NORTH
AMERICA. EASTERLY WAVE/UPPER LOW IS PROGRESSING TOWARD THE AREA.
WEAK FLOW AND VERY MOIST AIR MASS IN PLACE ACROSS THE AREA AT THIS
TIME.
THERE WERE NO PROBLEMS AT JET LEVEL. THE GFS/UKMET WERE DOING A
LITTLE BETTER THAN THE CANADIAN AND SREF AT MID LEVELS. SREF AND
ECMWF WERE DOING BEST ON THE SYNOPTIC SCALE WIND/PRESSURE FIELD
OUTSIDE OF THE MASSIVE INFLUENCE OF ALL THE OUTFLOW BOUNDARIES. THE
GFS/UKMET/SREF DID THE BEST ON THE LOW LEVEL THERMAL FIELD ALTHOUGH
MODELS WERE CLOSE.
TODAY/TONIGHT...OVERNIGHT CONVECTION HAS BEEN SLOWLY WINDING DOWN
OVER THE AREA. NUMEROUS OUTFLOW BOUNDARIES ARE AROUND WITH A COUPLE
OF CONVECTIVE VORTICITY MAXES AROUND AS WELL. BAND OF SHOWERS AND
THUNDERSTORMS HAS DEVELOPED TO THE EAST OF THE AREA. INDIVIDUAL
CELLS ARE MOVING TOWARD THE SOUTH WITH THE AREA MOVING SLOWLY TOWARD
THE WEST. THIS LOOKS TO BE IN RESPONSE A TIGHTENING MID LEVEL
BAROCLINIC ZONE BETWEEN INCOMING UPPER LOW FROM THE EAST AND THE
UPPER RIDGE OVER US.
ONE CONVECTIVE VORTICITY MAX OR 700 MB CIRCULATION STARTS OUT THE
DAY ROUGHLY ALONG THE COLORADO AND KANSAS BORDER. THIS GETS PULLED
SOUTH AS INCOMING UPPER LOW GETS CLOSER. ALSO WHAT LOOKS TO BE
SEVERAL SHORTWAVE TROUGHS ROTATING AROUND PARENT UPPER LOW ARE
EVIDENT. WHAT MAKES ALL OF THIS INTERESTING IS THE PROGRESSION OF
FEATURES FROM EAST TO WEST TODAY. SURFACE CONVERGENCE SETS UP OVER
THE EASTERN PORTION OF THE AREA AND MOVES WEST WITH EAST TO
SOUTHEAST WINDS THEN SPREADING ACROSS THE AREA.
NAM12...HRRR AND RAP INDICATE A LULL IN PRECIPITATION ACTIVITY
THROUGH MID MORNING. CONSIDERING THE DECREASING TREND OF
PRECIPITATION THAT LOOKS REASONABLE. THEN HOW QUICKLY AND WHERE THE
MODELS PUT THE NEXT BATCH OF PRECIPITATION GETS A LITTLE MORE
UNCERTAIN. THE 06Z NAM AND GFS HAVE PULLED THE MAIN AXIS OF
DEVELOPING PRECIPITATION FURTHEST EAST WITH THE NAM THE FURTHEST
EAST OF NOT ONLY THE TWO BUT THE WHOLE MODEL SUITE. THE 00Z ECMWF
TRENDED IN THIS DIRECTION AS WELL. THE LATEST RAP AND HRRR WOULD
SUPPORT THE GUIDANCE WHICH HAS THE MAIN BAND OF PRECIPITATION
DEVELOPING ALONG AND A FEW COUNTIES TO THE EAST OF THE COLORADO
BORDER. CONSIDERING WHERE THE FRONT/SURFACE CONVERGENCE IS...THAT
LOCATION MAKES SENSE.
CURRENT GRIDS THAT WERE JUST ISSUED HAVE THE MAIN BAND ALONG AND TO
THE WEST. DO NOT FEEL CONFIDENT TO ADJUST THAT EVEN NOW. I DID PULL
THE LIKELYS FURTHER EAST AND INCREASED TO HIGHER LIKELYS AS WELL.
WILL BRIEF DAY SHIFT ON THIS TO MAKE ANY SLIGHT ADJUSTMENTS.
RAINFALL WILL PROGRESS TO THE WEST THROUGH THE NIGHT AND BE MOSTLY
DONE BY LATE EVENING. HOWEVER...IF HEAVIER RAIN STARTS FURTHER EAST
THEN THAT WILL HAVE TO BE CHANGED.
HAD EARLIER TOYED WITH THE IDEA OF A FLASH FLOOD WATCH DUE TO THE
HEAVIER RAIN LAST NIGHT. PWS ARE RATHER HIGH 1.5 TO NEARLY
2.0 INCHES. HOWEVER...HEAVIER RAINFALL AMOUNTS WERE SPOTTY AND NOT
WIDESPREAD...FFG IS STILL RATHER HIGH...STORM MOTIONS ARE SLOW BUT
NOT LESS THAN 10 MPH...AND SREF PROBABILITIES OF A HALF INCH TO ONE
INCH OF 6 HOUR RAINFALL ARE VERY LOW. STILL BELIEVE WILL GET
MODERATE TO HEAVY RAINFALL OVER THE WESTERN HALF PER THE PWS AND A
DEEP WARM LAYER IN THE SOUNDINGS.
LOWERED MAXES FOR THE DAY DUE TO EXPECTED CLOUD COVER...DEVELOPING
PRECIPITATION...AND EASTERLY WINDS/COLD AIR ADVECTION. HOWEVER...I
MAY NOT HAVE MADE THEM COOL ENOUGH. LATER TONIGHT THERE MAY BE A LOW
PROBABILITY OF FOG BUT DID NOT INCLUDE AT THIS TIME.
MONDAY/MONDAY NIGHT...DID NOT CHANGE THE GOING FORECAST MUCH
PRECIPITATION WISE. WITH THE POSITION OF THE UPPER LOW AND THE
UPPER RIDGE BUILDING IN FROM THE EAST...MAJORITY OF THE AREA WILL BE
DRY FOR THE ENTIRE PERIOD. THERE WILL BE A VERY LOW CHANCE IN THE
EXTREME SOUTH BUT THAT IS ABOUT IT. DETERMINISTIC AND GEFS
PROBABILITIES SUPPORT THIS. MADE ONLY SLIGHT ADJUSTMENTS TO THE
GOING MAX TEMPERATURE FORECAST WITH GUIDANCE IN DECENT AGREEMENT.
DID COOL OF THE FAR WEST AND SOUTHWEST.
TUESDAY/TUESDAY NIGHT...AREA REMAINS DRY AS MID/UPPER LEVEL RIDGE
BUILDS IN FROM THE EAST. SOUTHERLY SURFACE WINDS INCREASE AS WELL.
MODELS IN DECENT AGREEMENT WITH THE MAXES SO ONLY MADE SLIGHT
ADJUSTMENTS THERE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 431 AM MDT SUN JUL 14 2013
SECOND HALF OF THE WORK WEEK LOOKS DRY AND WARMER AS A WEAK BUT
BROAD UPPER LEVEL RIDGE SITS ACROSS THE EASTERN TWO THIRDS OF THE
CONUS. BREEZY SOUTHERLY WINDS ON WED AND THURS WILL KEEP TEMPS AT OR
ABOVE NORMAL /LOW TO MID 90S/. NO PRECIP IS EXPECTED AND RELATIVE
HUMIDITY WILL REMAIN WELL ABOVE FIRE WX CRITERIA.
TOWARDS THE WEEKEND THE STORY CHANGES AS THE RIDGE IN THE EAST
BREAKS DOWN AND A SMALL BUT RELATIVELY STRONG VORT MAX MOVES ACROSS
NORTHERN COLORADO AND INTO THE CENTRAL HIGH PLAINS...THOUGH GUIDANCE
IS NOT IN VERY GOOD AGREEMENT ON THE PLACEMENT OF THE SYNOPTIC
FORCING. STILL...FEEL THERE IS GOOD ENOUGH AGREEMENT ON THIS AS AN
ASSOCIATED COLD FRONT COULD HELP WITH STORM DEVELOPMENT. MOISTURE
WILL BE NO PROBLEM AS SOUTH/SOUTHWESTERLY WINDS ALOFT WILL HELP TO
ADVECT MOIST MONSOONAL AIR INTO THE REGION...AND IN FACT ON SATURDAY
NIGHT GFS HAS PWATS OF OVER 1.50 INCHES. TEMPS WILL BE WARMEST ON
FRIDAY IN THE MID TO UPPER 90S...DROPPING TO UPPER 80S/LOW 90S ON
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1123 AM MDT SUN JUL 14 2013
AS UPPER LEVEL SYSTEM MOVE WEST AND FORCING INCREASING
THUNDERSTORMS WILL INCREASE IN COVERAGE WITH BEST CHANCES AT KGLD
TERMINAL. HEAVY RAIN COULD DECREASE VIS TO IFR/MVFR CATEGORIES AT
KGLD...HOWEVER AXIS OF HEAVIEST RAIN MAY BE FURTHER WEST AND
CONFIDENCE WASNT THERE TO LOWER CONDITIONS BELOW VFR AT EITHER
TERMINAL. THUNDERSTORM ACTIVITY SHOULD TRANSITION WESTWARD WITH
HIGH PRESSURE BUILDING INT FROM THE NORTHEAST THIS EVENING. WINDS
ARE GOING TO BE ERRATIC EARLY IN THE PERIOD WITH SURFACE TROUGH
STILL IN PLACE...THOUGH EVENTUALLY THEY SHOULD SHIFT TO THE
NORTHEAST AND THEN SOUTHEAST AROUND 12KT AS FRONT MOVES OVER BOTH
TERMINALS THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
103 PM EDT SUN JUL 14 2013
...Updated Aviation Discussion...
.FORECAST UPDATE...
Issued at 1200 PM EDT Sun Jul 14 2013
Deep southeasterly flow is in place across the Ohio Valley between
strong upper ridge building in from the mid Atlantic and the
retrograding upper low now over SW Missouri. Forecast is on track
for this afternoon, however have made a few small tweaks. So far,
any shower activity has struggled across the CWA as the deep
southeasterly component is downsloping off the Appalachians. This
component is also combining with a tongue of drier air evident on
water vapor imagery to limit showers as they move into east
Kentucky.
Still looks like the best coverage of showers or storms
(scattered) this afternoon will be across our SW CWA where deeper
moisture will reside and where downslope component is less
impactful. Still cannot rule out an isolated storm anywhere in the
CWA as full diurnal heating takes place, but think chances are low.
Have updated timing of afternoon showers/storms, but have not
changed coverages. Updated products already out.
&&
.SHORT TERM (Today through Monday)...
Issued at 300 AM EDT Sun Jul 14 2013
The short term period will continue the retrograding pattern with
the upper low now over southeastern Missouri moving west-southwest
to the southern Plains by tonight and Monday, as the upper high now
to our northeast expands westward into the Ohio Valley. In this
pattern, the best chance for convection will be today as a moisture
stream moves northwest between the upper low and high, with
suppressed chances on Monday.
In the near term, skies are clear to partly cloudy over central
Kentucky and southern Indiana, and this will hold through the
morning hours. Isolated showers early over parts of Larue and Hardin
counties have dissipated, and no more than an isolated shower or two
should still pop up elsewhere early this morning if at all. Patchy
fog could develop in a few river valleys by daybreak, otherwise
should not be much of a problem.
During the day today, the moisture stream in the short term models
shows precipitable water values of 1.5 to 2 inches with deep enough
moisture for scattered convective development this afternoon along
any mesoscale or cloud-clear type boundaries. It is difficult to pin
down at this time where cells might develop, although it appears
western parts of south-central Kentucky will have the best chance as
moisture streams up through the Tennessee Valley toward western
Kentucky. This would mean our northeastern counties might only see
isolated cells. This scenario is shown by the HRRR model, although
our in-house WRF develops scattered convection more over our
southeastern counties then propagates them northwest into north-
central Kentucky late this afternoon. Grids will reflect the HRRR,
which is supported by the NAM and GFS as well. In any storms, hail
should be less of a concern today than on Saturday given higher
temperatures aloft, although brief very heavy rain would be more
likely to occur along with CG lightning.
Any diurnal storms should die off this evening with a stabilizing
boundary layer. Skies should also become clear to partly cloudy
again. Patchy fog could develop late tonight in river valleys and
where any rain falls this afternoon.
On Monday, as the upper high builds in and heights and
temperatures aloft rise a bit, and as low-level moisture becomes a
little less prevalent, convection will be more hard pressed to
develop in the afternoon. As a result, while an isolated cell or two
could occur, the chances appear too small to include in the
forecast. Will go with a dry forecast under a partly cloudy sky.
High temperatures today should reach the upper 80s in many areas,
locally held down where showers occur. On Monday, highs should be
around 90 or the lower 90s in most areas, with maximum afternoon
heat indices in the mid to perhaps upper 90s.
.LONG TERM (Monday night through Saturday)...
Issued at 300 AM EDT Sun Jul 14 2013
Most of the upcoming week will degenerate into a broken record of a
forecast, as an anomalously strong upper ridge parks itself over the
Ohio Valley. Main sources of uncertainty center on convective
potential, and whether it will be the heat or the humidity making it
feel like close to 100 degrees each afternoon.
The atmosphere will be quite juicy with PWATs slightly above climo,
providing moderate to strong instability. Limiting factors will be
mid-level warming associated with the ridge, as H7 temps will run
10-11C, and the lack of any synoptic forcing. Convection will be
limited to diurnal activity, with probabilities below mentionable
thresholds in the north for much of the week. Highest POPs will be
in the low-end chance category, and confined to areas south of the
Western Kentucky and Bluegrass Parkways.
Temps are a bit of a crapshoot, as the moist ground is likely to
limit our warming at least in the first part of the week. Max temp
forecast undercuts extended GFS MOS by a few degrees, but still
expect to reach at least the lower 90s. Could see our heating catch
up with guidance later in the week as the heat dries out the ground.
Dewpoints in the lower 70s will push heat indices close to 100, but
any warmer temps will likely be offset by deeper mixing and slightly
lower dewpoints, so confidence is higher in the heat index forecast
than the actual temp or dewpoint forecast. Mins solidly above climo
in the lower to mid 70s each night.
POPs will increase as we head into the weekend, with a solid chance
on Saturday as the ridge starts to break down and we come under more
influence of the westerlies.
&&
.AVIATION (18Z TAF Update)...
Issued at 102 PM EDT Sun Jul 14 2013
Diurnally driven Cu around 3-4 k feet have started popping across
the region. This will continue through the afternoon, with chances
for scattered showers and storms at BWG. Have kept VCTS/CB groups in
at BWG. Confidence is not high enough in one of these showers/storms
impacting the terminal to go with predominant coverage, although a
storm would easily drop visibilities briefly to IFR. Will monitor
through the PM. Further northeast at SDF/LEX an isolated shower or
storm cannot be ruled out, however think coverage will be too sparse
to even mention VCTS at this time.
Otherwise, diurnally driven convection will diminish around sunset
this evening, with VFR conditions and a light SE wind continuing.
Could see some brief MVFR vis restrictions toward dawn at BWG.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......TWF
Long Term........RAS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1200 PM EDT SUN JUL 14 2013
.FORECAST UPDATE...
Issued at 1200 PM EDT Sun Jul 14 2013
Deep southeasterly flow is in place across the Ohio Valley between
strong upper ridge building in from the mid Atlantic and the
retrograding upper low now over SW Missouri. Forecast is on track
for this afternoon, however have made a few small tweaks. So far,
any shower activity has struggled across the CWA as the deep
southeasterly component is downsloping off the Appalachians. This
component is also combining with a tongue of drier air evident on
water vapor imagery to limit showers as they move into east
Kentucky.
Still looks like the best coverage of showers or storms
(scattered) this afternoon will be across our SW CWA where deeper
moisture will reside and where downslope component is less
impactful. Still cannot rule out an isolated storm anywhere in the
CWA as full diurnal heating takes place, but think chances are low.
Have updated timing of afternoon showers/storms, but have not
changed coverages. Updated products already out.
&&
.SHORT TERM (Today through Monday)...
Issued at 300 AM EDT Sun Jul 14 2013
The short term period will continue the retrograding pattern with
the upper low now over southeastern Missouri moving west-southwest
to the southern Plains by tonight and Monday, as the upper high now
to our northeast expands westward into the Ohio Valley. In this
pattern, the best chance for convection will be today as a moisture
stream moves northwest between the upper low and high, with
suppressed chances on Monday.
In the near term, skies are clear to partly cloudy over central
Kentucky and southern Indiana, and this will hold through the
morning hours. Isolated showers early over parts of Larue and Hardin
counties have dissipated, and no more than an isolated shower or two
should still pop up elsewhere early this morning if at all. Patchy
fog could develop in a few river valleys by daybreak, otherwise
should not be much of a problem.
During the day today, the moisture stream in the short term models
shows precipitable water values of 1.5 to 2 inches with deep enough
moisture for scattered convective development this afternoon along
any mesoscale or cloud-clear type boundaries. It is difficult to pin
down at this time where cells might develop, although it appears
western parts of south-central Kentucky will have the best chance as
moisture streams up through the Tennessee Valley toward western
Kentucky. This would mean our northeastern counties might only see
isolated cells. This scenario is shown by the HRRR model, although
our in-house WRF develops scattered convection more over our
southeastern counties then propagates them northwest into north-
central Kentucky late this afternoon. Grids will reflect the HRRR,
which is supported by the NAM and GFS as well. In any storms, hail
should be less of a concern today than on Saturday given higher
temperatures aloft, although brief very heavy rain would be more
likely to occur along with CG lightning.
Any diurnal storms should die off this evening with a stabilizing
boundary layer. Skies should also become clear to partly cloudy
again. Patchy fog could develop late tonight in river valleys and
where any rain falls this afternoon.
On Monday, as the upper high builds in and heights and
temperatures aloft rise a bit, and as low-level moisture becomes a
little less prevalent, convection will be more hard pressed to
develop in the afternoon. As a result, while an isolated cell or two
could occur, the chances appear too small to include in the
forecast. Will go with a dry forecast under a partly cloudy sky.
High temperatures today should reach the upper 80s in many areas,
locally held down where showers occur. On Monday, highs should be
around 90 or the lower 90s in most areas, with maximum afternoon
heat indices in the mid to perhaps upper 90s.
.LONG TERM (Monday night through Saturday)...
Issued at 300 AM EDT Sun Jul 14 2013
Most of the upcoming week will degenerate into a broken record of a
forecast, as an anomalously strong upper ridge parks itself over the
Ohio Valley. Main sources of uncertainty center on convective
potential, and whether it will be the heat or the humidity making it
feel like close to 100 degrees each afternoon.
The atmosphere will be quite juicy with PWATs slightly above climo,
providing moderate to strong instability. Limiting factors will be
mid-level warming associated with the ridge, as H7 temps will run
10-11C, and the lack of any synoptic forcing. Convection will be
limited to diurnal activity, with probabilities below mentionable
thresholds in the north for much of the week. Highest POPs will be
in the low-end chance category, and confined to areas south of the
Western Kentucky and Bluegrass Parkways.
Temps are a bit of a crapshoot, as the moist ground is likely to
limit our warming at least in the first part of the week. Max temp
forecast undercuts extended GFS MOS by a few degrees, but still
expect to reach at least the lower 90s. Could see our heating catch
up with guidance later in the week as the heat dries out the ground.
Dewpoints in the lower 70s will push heat indices close to 100, but
any warmer temps will likely be offset by deeper mixing and slightly
lower dewpoints, so confidence is higher in the heat index forecast
than the actual temp or dewpoint forecast. Mins solidly above climo
in the lower to mid 70s each night.
POPs will increase as we head into the weekend, with a solid chance
on Saturday as the ridge starts to break down and we come under more
influence of the westerlies.
&&
.AVIATION (12Z TAF Update)...
Issued at 625 AM EDT Sun Jul 14 2013
Visibilities at BWG and LEX early this morning so far have remained
VFR, and this should continue through daylight hours this morning.
Otherwise, stream of mid-level clouds are moving northwest over
western KY, with clear to partly cloudy skies elsewhere over central
KY. Forecast remains on track for sct-to-bkn clouds around 4 kft or
so to develop by late morning or afternoon, along with some mid
clouds. Scattered afternoon thunderstorms expected in vicinity of
BWG with isolated for SDF and LEX. Conditions will remain VFR except
briefly lower if any convective cells impact the TAF site. Any cells
should weaken/dissipate around 00z or slightly thereafter, with VFR
conditions continuing Sunday night.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........BJS
Short Term.......TWF
Long Term........RAS
Aviation.........TWF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
110 PM EDT SUN JUL 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH EARLY NEXT
WEEK WHILE A WEAK COLD FRONT IS EXPECTED TO CROSS THE AREA ON
MONDAY. A STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST
LATER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
110 PM UPDATE...NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS
UPDATE. ONLY MADE SOME TWEAKS TO SKY COVER AND MAX TEMPS TO MATCH
CURRENT SATELLITE AND SURFACE OBS TRENDS.
PREVIOUS DISCUSSION...CONTINUED WARM AND DRY THIS TERM. A LARGE
RIDGE OF HIGH PRES WILL REMAIN IN CONTROL W/ANOTHER DAY OF VERY
WARM TEMPERATURES.
LATEST SATL IR IMAGERY SHOWED SOME MID AND HIGH CLOUDS ROLLING
OVER THE UPPER RIDGE INTO PORTIONS OF NORTHERN AND EASTERN MAINE.
THE 00Z UA SHOWED A 50KT JETLET IN THE UPPER LEVELS ACROSS QUEBEC
AIDING IN THE CLOUDS PUSHING TOWARD THE CROWN OF MAINE. SOME STRATUS
AND FOG DEVELOPING OVER SWRN MAINE NEAR THE WATERVILLE AREA AND
ANOTHER BATCH SITTING OFF THE MAINE COAST. SATL LOOP SHOWED THIS
STRATUS AND FOG SLOWLY EDGING NORTHWARD TOWARD THE THE DOWNEAST
AND COAST. DECIDED TO ADD SOME PATCHY FOR THE INTERIOR DONWEAST
AND THE COAST. STRATUS AND FOG WILL LIFT AND BURN AFTER SUNRISE
THIS MORNING. THE LATEST HRRR AND LAMP GUIDANCE DOING QUITE WELL
W/THE TEMPERATURE PROFILE ATTM PER THE 06Z OBS AND HAVE LEANED
THIS WAY FOR THE DAYTIME HIGHS TODAY WHICH SHOWS UPPER 80S TO
AROUND 90 AWAY FROM THE COAST. COASTAL AREAS WILL BE COOLER DUE TO
A SEA BREEZE BUT STILL LOW TO MID 80S BEFORE THE BREEZE SETS UP.
THERE IS THE POTENTIAL FOR SOME FOG AGAIN LATER TONIGHT ESPECIALLY
FOR THE DOWNEAST AND COASTAL AREAS. THE LATEST NAM AND GFS
SOUNDINGS PICK THIS UP WELL W/AN INVERSION SETTING UP AND MOISTURE
TRAPPED RIGHT AT THE BLYR. TEMPERATURES OVERNIGHT WILL BE A TAD
WARMER THAN SATURDAY NIGHT W/READINGS EXPECTED TO BE IN THE LOW TO
MID 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A STRONG UPPER LEVEL RIDGE WILL BUILD WESTWARD FROM THE MID
ATLANTIC REGION AND BE CENTERED NEAR THE OH/IN BORDER BY 00Z TUE.
THIS WILL KEEP A WESTERLY FLOW OF VERY WARM AIR ACROSS THE REGION
ON MONDAY. H85 TEMPS OF +17 TO +18 C WITH H925 TEMPS +23 TO +25 C.
EXPECT HIGH TEMPERATURES ON MONDAY TO RANGE FROM THE UPPER 80S TO
LOWER 90S ACROSS MUCH OF THE REGION AWAY FROM THE COAST. A WEAK
COLD FRONT WILL CROSS THE REGION DURING MONDAY AFTERNOON BUT WITH
LITTLE IN THE WAY OF MOISTURE NOT EXPECTING ANYTHING MORE THAN
SOME INCREASING CLOUDS WITH THE PASSAGE OF THE FRONT. EXPECT
MAINLY CLEAR SKIES MONDAY NIGHT WITH LOW TEMPERATURES MAINLY IN
THE 60S. TUESDAY WILL BE ANOTHER MAINLY DRY DAY BUT IT WILL BE A
TAD COOLER THAN MONDAY WITH HIGH TEMPERATURES GENERALLY IN THE LOW
TO MID 80S NORTH AND NEAR 90 DEGREES ACROSS CENTRAL AND INTERIOR
DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE STRONG UPPER RIDGE WILL CONTINUE TO BUILD WESTWARD AND BE CENTERED
NEAR IL BY 00Z THU. AS THE UPPER RIDGE BUILDS WEST THE UPPER FLOW
ACROSS OUR AREA WILL BECOME MORE ZONAL DURING WEDNESDAY ALLOWING A
COLD FRONT TO CROSS THE REGION LATER WEDNESDAY AND WEDNESDAY
EVENING. LOOKS LIKE THE STAGE COULD BE SET FOR STRONG TO POSSIBLY
SEVERE CONVECTION TO DEVELOP WEDNESDAY AFTERNOON. STILL WAY TOO EARLY
FOR ANY MENTION OF ENHANCED WORDING AT THIS TIME BUT THE THREAT WILL
NEED TO BE MONITORED.
THE FRONT WILL MOVE EAST OF THE COAST BY EARLY THURSDAY MORNING AS
COOLER AND DRIER AIR BUILD IN AS HIGH PRESSURE BUILDS EAST. A ZONAL
FLOW WILL KEEP THE CHANCE FOR SHOWERS IN THE FORECAST FOR MUCH OF
THE REMAINDER OF THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL
LEVELS.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR THROUGH TONIGHT W/THE EXCEPTION FOR KBGR AND KBHB
AS SOME SHALLOW FOG COULD ALLOW FOR MVFR AND POSSIBLY IFR BRIEFLY
EARLY SUNDAY MORNING.
SHORT TERM: MAINLY VFR MONDAY AND TUESDAY. A COLD FRONT WILL CROSS
THE REGION LATER WEDNESDAY AND WEDNESDAY EVENING. CONFIDENCE IS
INCREASING FOR WIDESPREAD THUNDERSTORMS TO DEVELOP IN ADVANCE OF
THE FRONT WEDNESDAY AFTERNOON RESULTING ON PERIODS OF MVFR/IFR
CONDITIONS IN AND HEAVIER SHOWERS/THUNDERSTORMS. MAINLY VFR
RETURNS FOR THURSDAY.
&&
.MARINE...
NEAR TERM: A SWELL WILL CONTINUE THROUGH TONIGHT W/WAVE HEIGHTS OF
2 FT. WINDS WILL BE LIGHT AVERAGING SPEEDS OF LESS THAN 10 KTS.
SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAY ME
1242 PM EDT SUN JUL 14 2013
.SYNOPSIS...
WARMER AND MORE HUMID HIGH PRESSURE BUILDS OVER THE REGION THROUGH
THE MIDDLE OF THE WEEK. IT SHOULD BE MAINLY RAIN FREE THROUGH
TUESDAY. BY MID-WEEK...WE WILL SEE SEVERAL ATTEMPTS BY A COLD
FRONT TO MOVE SOUTH INTO THE HIGH PRESSURE...AND EVEN THOUGH IT
WILL NOT REALLY BREAK THE WARM AND HUMID AIR...IT WILL PRODUCE THE
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
1240 PM...ONLY MINOR ADJUSTMENT TO 1ST PERIOD GRIDS TO REFLECT THE
PRESENT MESONET VALUES FOR THIS ESTF UPDATE.
PREV DISC...
925 AM...I MADE SOME ADJUSTMENTS FOR SKY COVER AS LATEST GOES
IMAGERY INDICATING A LINGERING AREA OF MID CLOUDS ACROSS NORTHERN
NEW HAMPSHIRE INTO WESTERN MAINE. OTHERWISE...I ADJUSTED 1ST
PERIOD GRIDS BASED LARGELY TO REFLECT THE MESONET AND TO
INCORPORATE THE LATEST HRRR OUTPUT INTO SURFACE WIND GRIDS.
PREV DISC...
STRATUS OFFSHORE BEHAVING WELL...AND MAINLY STAYING THERE...BUT
OCCNLY CREEPING ONSHORE BRIEFLY. THIS FOG/CLOUD BANK WILL LKLY
REMAIN OFFSHORE THROUGH THE DAY...BUT SHOULD CREEP BACK FROM THE
COAST THIS MORNING. MEANWHILE OVER NH STRATUS THAT FORMED LAST
EVENING IS NOT HOLDING TOGETHER VERY WELL...AND LOOKS PATCHY FOR
THIS MORNING.
THE 500MB RIDGE BUILDS JUST TO OUR SW TODAY...WITH HEIGHTS
APPROACHING 6000 METERS. THE NAM/GFS CONTINUE TO WANT TO PRODUCE
SOME QPF IN SRN NH AND SW ME AROUND 18Z TODAY...BUT DO NOT SEE IT AS
ANY SORT OF WIDESPREAD EVENT. LOOKING AT THE MESOSCALE MODELS...THE
RAP/HRRR AND LOCAL WRF...IT LOOKS MORE LIKE SOME ISOLD CONVECTION
DEVELOPING. GIVEN THE SURGE OF LOW-LVL MOISTURE THIS MORNING...AND
PERHAPS SOME DIFFERENTIAL HEATING GENERATED FROM LINGERING CLUSTERS
OF STRATUS AND ALTOSTRATUS...THIS MAY BE THE CASE. HAVE CALLED IT
ISOLD SHRA/TSRA...ALTHOUGH WITH DECENT MID-LVL CAPPING IT WILL BE
HARD TO GENERATE ANY TALL CUMULUS AND STRONGER UPDRAFTS.
MAX TEMPS SHOULD CLIMB WELL INTO THE 80S INLAND...WITH A FEW 90S
IN THE HOT SPOTS. LINGERING MORNING CLOUDS COULD SHAVE A DEGREE OR
TWO OFF THE HIGHS IN SOME SPOTS IN SRN NH. AND SEA BREEZE WILL
DEVELOP ALONG THE COAST THIS AFTERNOON.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/...
FOR TONIGHT...INLAND AREAS SHOULD CLEAR OF MOST CLOUDS...BUT WILL
HAVE TO WATCH FOR OFFSHORE FOG AND CLOUDS WORKING IN ALONG THE
COAST. WE SHOULD RETURN TO HUMID CONDITIONS...WITH TDS IN THE
60S...THIS WILL LIMIT LOWS TO LOW 60S IN THE N...AND MID TO UPPER
60S EVERYWHERE ELSE.
MONDAY LOOKS TO BE HOT AND HUMID ACROSS ALMOST ALL THE CWA. AS THE
500 MB RIDGE RETROGRADES WWD...WILL SEE MID-UPP LVL ANTICYCLONIC
FLOW DEVELOP...WHICH WILL PRODUCE ENOUGH SUBSIDENCE TO KEEP US HOT
AND RAIN FREE. HIGHS INLAND WILL BE IN THE UPPER 80S TO LOWER 90S
WITH TDS IN THE MID TO UPPER 60S. SHOULD SEE A LITTLE BETTER SW
FLOW AT MID-LVLS...WHICH SHOULD MIX DOWN TO THE SFC A BIT..AND
KEEP SEA BREEZE FROM MOVING AS FAR INLAND AS IT MOVES ONSHORE
LATER IN THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE TO SHOW A WEAKENING BACKDOOR FRONT PUSHING
SOUTHWARD DURING THE DAY TUESDAY AS THE RIDGE OF HIGH PRESSURE
SLIPS SOUTHWARD. THE FRONT THEN LIFTS EAST DURING THE DAY
WEDNESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH THIS
FEATURE...ALTHOUGH ONLY WIDELY SCATTERED SHOWERS/TSTMS POSSIBLE
WITH THIS FEATURE AS ATMOSPHERE ONLY BECOMES SLIGHTLY UNSTABLE.
OTHER WEAKENING FRONTS ARE FORECAST TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY...EACH BRINGING THE THREAT OF SHOWERS OR
THUNDERSTORMS. MODELS CONTINUE TO SHOW A WAVE MOVING ALONG THE
FRONTAL BOUNDARY LATE THURSDAY AND FRIDAY...INCREASING THE THREAT
OF SHOWER AND THUNDERSTORMS LATE IN THE WEEK.
MODELS HAVE BACKED OFF STRONG FRONTAL PASSAGE LATE IN
WEEK...INSTEAD BRINGING A SOMEWHAT WEAKER FRONT THROUGH EARLY
NEXT WEEK.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MAINLY VFR THROUGH TODAY. FOG/STRATUS JUST NOT
GETTING ORGANIZED...ALTHOUGH IT IS OUT THERE EARLY THIS MORNING.
CANNOT RULE SOME PERIODS OF MVFR THROUGH ABOUT 13Z. FOG/CLOUD BANK
LIKELY TO LINGER OFFSHORE TODAY...AND COULD MOVE ONSHORE AROUND OR
SHORTLY AFTER SUNSET AT THE COASTAL TERMINALS THIS EVENING AND
INTO THE OVERNIGHT. VLY FOG ALSO A POSSIBILITY TONIGHT. ALL
TERMINALS SHOULD BE VFR DURING THE DAY ON MONDAY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED THROUGH THURSDAY WITH
IFR CONDITIONS POSSIBLE IN EARLY MORNING VALLEY FOG IN FAVORED
LOCATIONS. MVFR CONDITIONS ALSO POSSIBLE IN AFTERNOON SHOWERS AND
THUNDERSTORMS EACH DAY. ONLY WIDELY SCATTERED SHOWERS/TSTMS
EXPECTED TUESDAY...BECOMING MORE NUMEROUS BY THURSDAY.
&&
.MARINE...
SHORT TERM...WINDS WILL REMAIN LIGHT AND SEAS BELOW SMALL CRAFT
THRESHOLD. ONLY ISSUE WILL BE LOWERED VSBY AS FOG BANK LOOKS TO
SIT OFFSHORE TODAY...AND POSSIBLY MOVE ONSHORE THIS EVENING.
LONG TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA CRITERIA.
AREAS OF FOG MAY RESTRICT VISIBILITIES...ESPECIALLY IN THE
MORNINGS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
124 PM EDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EDT SUN JUL 14 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG
EXTENDING WWD FM THE NE CONUS THRU THE GREAT LKS ON THE SE FLANK OF
FASTER WSW FLOW ALF OVER CANADA. 00Z APX RAOB SHOWS A STABLE...BONE
DRY AIRMASS /PWAT 0.77 INCH/ CLOSER TOWARD THE CORE OF THIS UPR RDG.
SO THE SE HALF OF THE CWA IS MOCLR. FARTHER TO THE W...THERE IS A
BAND OF MAINLY MID CLDS STRETCHING FM THE NW HALF OF LK SUP SWWD
THRU MN AND INTO IOWA. IN FACT...THE 00Z MPX RAOB SHOWS A GOOD DEAL
OF MID LVL MSTR WITH PWAT 1.93 INCH...188 PCT OF NORMAL. BUT AN
ABSENCE OF ANY SGNFT DYNAMIC FORCING UNDER THE UPR RDG AXIS WITH THE
00Z GRB/MPX RAOBS INDICATING A CAPPING INVRN THAT WEAKENS A BIT
FARTHER TO THE W AWAY FM THE HIER HGTS HAS IS ALLOWING FOR ONLY SOME
ISOLD -SHRA OVER MAINLY WRN UPR MI AND NW WI WHERE THE RUC ANALYSIS
SHOWS A BIT HIER H7 DEWPTS NEAR 10C. ANOTHER FACTOR TENDING TO
RESTRICT THE SHRA COVERAGE/INTENSITY IS A FEED OF DRIER SFC-H85 AIR
FM THE S SHOWN ON THE 00Z QUAD CITIES IOWA RAOB. SPC MESOANALYSIS
INDICATES MUCAPE NOT MUCH HIER THAN 100-250 J/KG. FARTHER TO THE
NW...A FAIRLY POTENT SHRTWV JUST W OF LK WINNIPEG EMBEDDED IN THE
WSW FLOW ALF OVER CANADA IS CAUSING SOME SCT SHRA/TS UNDER AXIS OF
GREATER INSTABILITY OVER NDAKOTA/FAR NW MN. BUT VERY DRY AIRMASS
SHOWN ON THE 00Z INL RAOB IS LIMITING THE EWD PUSH OF THESE SHRA.
TODAY...AS THE UPR RDG AXIS EXPANDS TO THE W AND H7 HGTS RISE
ACCORDINGLY...MODELS IN GOOD AGREEMENT SHOWING SE EDGE OF HIER H7
DEWPTS RETREATING SLOWLY TO THE NW AS WELL. LOWER H85 DEWPTS
ARRIVING FM THE S WL ALSO TEND TO END ANY SHRA. SO WL FCST LINGERING
POPS OVER THE NW LAND CWA THIS MRNG TO PUSH OUT INTO LK SUP. WITH
ABUNDANT SUNSHINE OVER THE CENTRAL AND E ALONG WITH H85 TEMPS NEAR
17C...EXPECT HI TEMPS TO RISE WELL INTO THE 80S AGAIN AWAY FM THE
MODERATING INFLUENCE OF MAINLY LK MI IN LLVL SSW FLOW. BUT RATHER
WEAK PRES GRADIENT FCST THIS AFTN WL ALLOW FOR LK BREEZE FORMATION
OFF LK SUP AS WELL.
TONIGHT...MODELS IN GOOD AGREEMENT SHOWING AXIS OF HIER H7 MSTR
REMAINING OVER NW LK SUP OVERNGT ON THE NW FLANK OF NEARLY STNRY UPR
RDG CENTERED OVER THE LOWER GRT LKS. ANOTHER SHRTWV IS FCST TO RIDE
NEWD THRU MN LATE TNGT IN THE WSW FLOW ALF ARND THE RDG...BUT BULK
OF MODELS INDICATE ANY ASSOCIATED PCPN WL REMAIN OVER THE LK WITH
MID LVL CAPPING OVER THE LAND CWA CLOSER TO THE HIER HGTS DESPITE
ARRIVAL OF MORE HUMID LLVL AIR THAT WL ALLOW FOR SOME FOG FORMATION
AT LEAST OVER THE W HALF.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM EDT SUN JUL 14 2013
UPPER LEVEL HIGH CENTERED OVER MID ATLANTIC EXPANDS WESTWARD ACROSS
THE OHIO VALLEY AND MISSISSIPPI RIVER VALLEY INTO WEDNESDAY. LATER
WEDNESDAY THROUGH THURSDAY NORTHERN STREAM TROUGH/MID-LEVEL SPEED
MAX SMASHES THE RIDGE SOUTH OF UPPER GREAT LAKES. APPEARS THAT
NORTHERN STREAM TROUGH WILL BE STRONG ENOUGH TO PUSH SFC-H85 FRONT
ACROSS UPR MICHIGAN WED AFTN THROUGH THURSDAY. TROUBLE IS THAT FRONT
WILL NOT MOVE TOO FAR SOUTH AS IT BECOMES PARALLEL TO UPPER FLOW.
WITH FRONT CLOSE BY AND SINCE UPPER LAKES WILL BE ON NORTHERLY EDGE
OF HIGHER INSTABILITY GRADIENT AND ON SOUTHERN EDGE OF STRONGER
WINDS ALOFT...WILL HAVE CHANCE POPS WEDNESDAY THROUGH THURSDAY
NIGHT. AT THIS POINT...BEST CHANCES OF WIDESPREAD SHRA/TSRA WOULD BE
WEDNESDAY THEN AGAIN THURSDAY AFTN/EVENING. BY LATER FRIDAY AND INTO
NEXT WEEKEND...HEIGHTS FROM THE NORTH LOWER ENOUGH TO PUSH FRONT FAR
ENOUGH SOUTH TO SHOW A DRYING TREND.
HIGH PRESSURE BUILDING ALOFT ON MONDAY WHILE WEAK HIGH PRESSURE IS
OVER THE AREA AT THE SFC. COULD BE LOCALIZED LAKE BREEZES OFF LK
SUPERIOR NCNTRL AND ON KEWEENAW. PATTERN FAVORS MOST LAKE COOLING
OFF LK MICHIGAN THOUGH. WEAK CONVERGENCE ALONG LK BREEZES BUT
MLCAPES ARE MEAGER WITH SUBSIDENCE FROM BUILDING RIDGE ALOFT.
CU MAY BE ENHANCED OVR CNTRL CWA BUT WILL NOT INCLUDE ANY POPS
DUE TO MINIMAL INSTABILITY. SFC RIDGE AXIS MOVES EAST BY TUESDAY
WHILE SFC TROUGH CROSSES NORTHERN MANITOBA AND NORTHWEST ONTARIO.
GRADIENT SSW WIND SHOULD LIMIT LAKE SUPERIOR BREEZE. H85 TEMPS SURGE
TO +18C...SO EXPECT TEMPS INTO THE UPPER 80S AWAY FM LK MICHIGAN.
HIGHER DWPNT/INSTABILITY THAN MONDAY WITH MLCAPES OVER 1000
J/KG...BUT OVERALL THE LOW-LEVEL CONVERGENCE IS MINIMAL. COULD
SEE ISOLD-SCT SHRA/TSRA FORM OVER CNTRL CWA NEAREST LK MICHIGAN LAKE
BREEZE. WITH DEEP LAYER SHEAR OVER 30 KTS...CANNOT RULE OUT AN ISOLD
SVR STORM.
GENESIS REGION FOR MORE ORGANIZED SHRA/TSRA ON TUESDAY EVENING MAY
BE IN THE VCNTY OF UPPER LAKES INTO NORTHERN PLAINS CLOSER TO TAIL
END OF SFC TROUGH EXTENDING SOUTHWEST OF SFC LOW CROSSING NORTHERN
ONTARIO. MAX MOISTURE ADVECTION/LOW-LEVEL JET WOULD BE OVER NW
PORTION OF UPPER LAKES. MEAN STORM MOTION/FORWARD PROPAGATING
CORFIDI VECTORS AND 850-300MB THICKNESS SUGGEST THAT IF SHRA/TSRA
FORM IN THE EVENING THEY WOULD TRACK ACROSS UPR MICHIGAN TUE NIGHT.
WILL GO WITH LOW CHANCES ON TUESDAY NIGHT ACROSS WESTERN CWA. IDEA
MATCHES SPC SREF 3 HR PROBABILITY FOR TSRA. IF ORGANIZED CONVECTION
MATERIALIZES...WOULD AGAIN BE SOME RISK OF SVR MAINLY IN THE FORM OF
STRONG WIND GUSTS.
SFC FRONT AND DWPNTS POOLING TO NEAR 70 DEGREES IN AREA ON
WEDNESDAY. DEPENDING HOW OVERNIGHT CONVECTION GOES THERE MAY BE AN
INITIAL ROUND OF SHRA/TSRA OVER THE AREA ON WEDNESDAY MORNING WITH
ANOTHER INCREASE DURING THE AFTN. MLCAPES PUSHING 1500J/KG WITH DEEP
LAYER SHEAR 30-40 KTS INDICATES THIS COULD BE YET ANOTHER SVR
WEATHER DAY. SYNOPTIC PATTERN POINTS TO WIND/BOW ECHO TYPE OF
SITUATION. MUCH TOO EARLY TO GET CAUGHT UP IN THESE DETAILS YET
THOUGH. SOME INDICATIONS THAT FRONT MAY BE THROUGH NORTHERN TIER OF
CWA WITH MAIN FOCUS FOR AFTN CONVECTION OVER THE SCNTRL IN AREA OF
STRONGER SFC-H85 CONVERGENCE. CONSENSUS POPS HAVE THE HIGHER POPS
SCNTRL WITH LESSER POPS NEAR LK SUPERIOR. TEMPS COULD SHOW A PRETTY
SHARP RANGE ON WEDNESDAY...ESPECIALLY IF ONSHORE NORTH WINDS DEVELOP
IN THE NORTH CWA EARLIER IN THE DAY. MIXING TO H85 TEMPS STILL NEAR
+17C YIELDS HIGHS INTO THE UPPER 80S SCNTRL. 70S TO NEAR 80 DEGREES
WILL BE THE CASE NEAR LK SUPERIOR. OVERALL A LULL EXPECTED LATER
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. BY THURSDAY AFTN...SFC-H85
WINDS BACKING MORE SW AHEAD OF ANOTHER SHORTWAVE/H5 SPEED MAX
DIGGING INTO NORTHERN PLAINS. H85 WARM AIR ADVECTION ALONG WITH
MOISTURE TRANSPORT AND FACT THAT UPR MICHIGAN IS FCST TO BE ALONG
NORTH EDGE OF MUCAPE GRADIENT SUGGESTS ANOTHER ROUND OF SHRA/TSRA
OVER PARTS OF THE AREA THURSDAY AFTN/THURSDAY NIGHT. MAY EVEN SEE
ANOTHER CONVECTIVE WIND TYPE OF SITUATION.
CONSENSUS POPS SHOW THE DRYING TREND KICKING IN ON FRIDAY FM NORTH
TO SOUTH AS MAIN SFC COLD FRONT PLOWS INTO THE REGION. EXPECT DRY
WEATHER AND COOLER TEMPERATURES TO BE MAIN WEATHER STORY BY TIME
NEXT WEEKEND ARRIVES. ONSHORE GRADIENT NORTH WINDS LIKELY WILL KEEP
TEMPS IN THE 60S ALONG LK SUPERIOR FRIDAY AND SATURDAY. MAY ALSO SEE
INCREASED SWIM RISK AT THAT TIME AS WELL. IN THE MEANTIME...A WARM
AND HUMID SUMMERTIME REGIME WILL BE IN PLACE THROUGH MUCH OF THE
UPCOMING WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 123 PM EDT SUN JUL 14 2013
DRIER AIR HAS OVERCOME KSAW THIS AFTERNOON...WHICH HAS KEPT SKIES
MOSTLY SUNNY THROUGH THE DAY. AS OF 17Z THIS AIR WAS SLOWLY CREEPING
NORTHWESTWARD TOWARDS KIWD/KCMX. CLOUDS AT KIWD ARE ALREADY BREAKING
UP...AND WILL CONTINUE TO DO SO THROUGH THE AFTERNOON. KCMX MAY BE A
LITTLE BIT SLOWER...AND MAY EVEN SEE A STRAY SHOWER OR TWO...BUT
CONDITIONS WILL NOT DROP BELOW VFR.
OTHERWISE...HIGH PRESSURE WILL KEEP CONDITIONS MOSTLY QUIET. WITH
VERY LIGHT WINDS...MOSTLY CLEAR SKIES...AND ANOTHER BATCH OF
MOISTURE SNEAKING IN FROM THE SOUTH OVERNIGHT...CANNOT RULE OUT SOME
PATCHY FOG DEVELOPING TONIGHT AT ALL THREE TAF SITES. FOR NOW HAVE
KEPT VISIBILITIES MVFR FOR A FIRST GUESS...AS FOG IS NOT EXPECTED TO
BE PROBLEMATIC.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EDT SUN JUL 14 2013
WITH HIGH PRESSURE NUDGING INTO THE UPPER GREAT LAKES AND A WEAK LOW
PRESSURE TROUGH TO THE WEST...WINDS WILL GENERALLY REMAIN LESS THAN
15-20 KNOTS THROUGH THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...MCD
MARINE...KC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
305 PM MDT SUN JUL 14 2013
.SHORT TERM...VALID FOR MON AND TUE...
ACTIVE WEATHER WILL CONTINUE TONIGHT THROUGH TUE NIGHT. A BAND OF
CONVECTION CONTINUED MOVING THROUGH SE MT THIS AFTERNOON PER RADAR
IMAGERY. THE BAND WAS BEING FUELED BY JET DIVERGENCE. OTHER
CONVECTION WAS MOVING INTO THE SW PART OF THE AREA AHEAD OF A
SHORTWAVE MOVING INTO W MT AND WEAK WAVES SW OF THE AREA. A WARM
FRONT WILL MOVE N THROUGH THE REGION TONIGHT ACCOMPANIED BY
ISENTROPIC LIFT. THE HRRR HAS BEEN GENERATING CONVECTION OVER THE
S CENTRAL PART OF THE AREA FOR THE LAST FEW RUNS DURING THE
EVENING. THE RAP SHOWED 1000 J/KG OF SURFACE CAPE IN THIS AREA AND
THE WRF HAD DECENT BULK SHEAR...SO STORMS IN THIS AREA COULD BE
STRONG. A LOW-LEVEL JET WILL HELP SUSTAIN CONVECTION IN THE E
THROUGH THE NIGHT. THUS WENT WITH CHANCE POPS S TAPERING TO SLIGHT
CHANCE N DURING THE EVENING...AND SLIGHT CHANCE E OVERNIGHT.
PRECIPITABLE WATERS AROUND AN INCH WILL SUPPORT HEAVY RAIN WITH
THE THUNDERSTORMS.
MON WILL BE A PREFRONTAL DAY. SHORTWAVES WILL CONTINUE MOVING
THROUGH THE SW FLOW ALOFT. INVERTED-V SOUNDINGS WERE FORECAST FOR
THE CENTRAL AND W ZONES. KMLS WAS CAPPED ON BUFKIT. CAPES AT KBHK
WERE 1000-1500 J/KG...BUT SOUNDINGS DID NOT SHOW MUCH IN THE WAY
OF LIFT. HAD CHANCE POPS SE IN THE MORNING NEAR SHORTWAVE ENERGY
THEN ISOLATED TO SCATTERED POPS IN THE AFTERNOON AND EVENING DUE
TO ADDITIONAL SHORTWAVES AND THE APPROACH OF THE FRONT. GOOD
MIXING WILL PROMOTE HIGH TEMPERATURES IN THE 90S IN MANY AREAS.
KEPT POPS THROUGH THE NIGHT DUE TO THE COLD FRONT.
THE FRONT WILL SETTLE OVER THE REGION ON TUE AND THE FLOW WILL
TURN E. HAD MAINLY ISOLATED POPS THROUGH THE DAY. STRONG THETA-E
RIDGE WILL HELP CONTINUE CHANCES FOR THUNDERSTORMS TUE NIGHT. TUE
WILL BE COOLER WITH READINGS IN THE 80S BUT A THERMAL RIDGE WILL
KEEP THE E WARMER WITH TEMPERATURES AROUND 90. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
THE THEME IN THE EXTENDED FORECAST REMAINS SUMMER TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS EACH DAY. BROAD SUMMER RIDGING
WILL FINALLY BE ESTABLISHED ACROSS MOST OF THE CONUS WITH THE
FORECAST AREA REMAINING ON THE NORTHERN EXTENT OF THE RIDGE WITH
THE JET STREAM NEARBY TO THE NORTH.
THIS SETUP WILL ALLOW INCREASING MID-LEVEL MOISTURE ACROSS THE
FORECAST AREA FROM THE MONSOONAL FLOW OUT OF THE SOUTH.
FURTHERMORE...LOW-LEVEL MOISTURE WILL BE ON THE INCREASE THANKS TO
GULF MOISTURE BEING TRANSPORTED UP THE GREAT PLAINS AND INTO THE
FORECAST AREA FROM THE EAST AND NORTHEAST. THIS WILL KEEP PW
VALUES RUNNING BETWEEN 1 AND 1.5 INCHES ACROSS THE FORECAST AREA
WEDNESDAY THROUGH FRIDAY. THESE WILL BE THE BEST DAYS IN THE
EXTENDED FORECAST FOR THUNDERSTORM ACTIVITY. DEEP LAYER SHEER
(0-6KM) SHOULD BE WEAK ON WEDNESDAY AS THE JET STREAM REMAINS
MOSTLY NORTH OF THE FORECAST AREA...THUS EXPECT STORMS TO BE HEAVY
RAINERS BUT THE SEVERE POTENTIAL SHOULD BE VERY LIMITED. DEEP
LAYER SHEER SHOULD INCREASE TO AROUND 40 KTS FOR THURSDAY AND
FRIDAY AS THE JET SAGS FARTHER SOUTH. THIS WILL BE COUPLED WITH
COOLER 700 MB TEMPERATURES. THUS EXPECT THUNDERSTORMS ON THURSDAY
AND FRIDAY COULD BE ON THE STRONG SIDE WITH SOME ISOLATED SEVERE
POTENTIAL.
STRONGER ZONAL TO NORTHWESTERLY FLOW ESTABLISHES OVER THE FORECAST
AREA BY THE WEEKEND. THIS HELPS TO KEEP MONSOONAL MOISTURE LOCKED
TO THE SOUTH OF THE FORECAST AREA WHILE THE LOW-LEVEL MOISTURE
BECOMES SHIFTED TO THE EAST. THIS SHOULD MINIMIZED OUR CHANCES OF
PRECIPITATION THIS WEEKEND.
TEMPERATURES WILL REMAIN JUST ABOVE SEASONAL NORMALS IN THE UPPER
80S AND LOW 90S THROUGH THE EXTENDED FORECAST.
CHURCH
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE STRONGEST SOUTH OF
KBIL THIS AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS ARE
POSSIBLE WITH THE STRONGEST CELLS ALONG WITH GUSTY WINDS. EXPECT
CLEARING CONDITIONS AFTER MIDNIGHT. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 061/095 064/083 062/090 066/092 065/093 065/094 065/094
32/T 22/T 32/T 32/T 33/T 31/B 11/B
LVM 052/091 054/085 056/091 055/092 056/093 052/095 052/095
43/T 33/T 33/T 33/T 33/T 32/T 21/B
HDN 061/096 062/087 058/092 061/093 063/093 061/095 061/096
42/T 22/T 32/T 32/T 32/T 21/B 11/B
MLS 065/095 067/089 064/093 068/093 066/093 067/094 066/094
22/T 22/T 22/T 22/T 22/T 21/B 11/U
4BQ 062/093 062/092 061/093 063/091 065/090 061/092 060/093
43/T 22/T 21/U 12/T 22/T 21/B 11/U
BHK 060/087 062/088 059/091 064/090 064/088 062/089 061/090
43/T 22/T 21/B 22/T 22/T 22/T 21/U
SHR 058/091 058/089 058/092 058/091 058/090 057/092 057/094
42/T 22/T 22/T 22/T 33/T 31/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
306 PM CDT SUN JUL 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 306 PM CDT SUN JUL 14 2013
FRONTAL BOUNDARY CONTINUES TO WOBBLE AROUND BUT NOT MOVE
MUCH...CONTINUING FROM JUST SOUTHWEST OF KFAR TO AROUND KBDE. THINK
THERE SHOULD BE SOME LIFTING NORTHWARD OF THE FRONT LATER THIS
AFTERNOON AND INTO TONIGHT...WITH KFAR AND KBJI SHOWING SOME
SCATTERED SHRA AND TS...ALONG WITH MVFR CEILINGS AT TIMES UNDER
DEEPER MOISTURE. NORTH OF THE FRONT...KDVL...KGFK AND KTVF HAVE ALL
GONE TO VFR CIGS...AND THIS TREND SHOULD CONTINUE THROUGH THE REST
OF THE TAF PERIOD. REMOVED PRECIP MENTION AS THINK THAT ANY
ACTIVITY WILL BE IN THE GENERAL VICINITY OF THE FRONT AND THAT
SHOULD BE WELL SOUTH OF THOSE TAF SITES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1252 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 1252 PM CDT SUN JUL 14 2013
THIS EARLY AFTERNOON UPDATE REVOLVES AROUND THE SLOW MOVING
CONVECTIVE AREA OVER THE SOUTHEAST PORTION OF THE CWFA. WE ISSUED
AN FLS FOR THE 1.5 TO 2.5 INCHES OF RAIN IN GRANT AND OTTER-TAIL
COUNTIES. 88D ESTIMATES SUGGEST ISOLATED 3 TO 4 INCH AMOUNTS...
YET REGION IS DRY ENOUGH AND RATES SLOW ENOUGH THAT FLASH FLOODING
NOT LIKELY. THE 88D ESTIMATES SUGGEST RAINFALL RATES OF UP TO 0.50
INCH/HOUR MOVING THROUGH THE FLS AREA. HRRR SUGGESTS AN ADDITIONAL
1 TO 2 INCHES ARE POSSIBLE IN THAT AREA OVER THE NEXT 15 HOURS.
WILL MONITOR FOR POSSIBLE UPGRADE IF STRONGER CONVECTION DEVELOPS.
PWATS ARE EXTREMELY HIGH FOR OUR AREA...GTR 2 INCHES...DECREASING
FORCING WITH DRIER AIR INTRUDING FROM THE NORTH AND CONFLUENT FLOW
ALOFT SHOULD HOLD WIDESPREAD EXCESSIVE AMOUNTS DOWN.
UPDATE ISSUED AT 923 AM CDT SUN JUL 14 2013
UPDATED THROUGH THE AFTERNOON TO ADJUST FOR QUASI-STATIONARY BAND
OF CONVECTION. LEANED ON THE HRRR THROUGH 18Z AND SREF THROUGH 00Z
TO BLEND. HAVE UPPED THE QPF TO ACCOUNT FOR THE OBSERVED HEAVIER
RAINS IN PROGRESS. A PWS IN HOFFMAN/GRANT COUNTY/SHOWS 1.8 INCHES
MIDNIGHT THROUGH 9AM. BIAS FFMP/LEGACY AND DUAL POL QPE A TAD HOT
BUT HAVE GENERAL IDEA. WILL BLEND TEMPS DOWN IN CLOUDS AND RAIN
AREAS AS WELL.
UPDATE ISSUED AT 640 AM CDT SUN JUL 14 2013
HAVE CANCELED SVR TSTM WATCH FOR FAR SERN ND COUNTIES. INCREASING
CONVECTION OVER SERN SD AND DECREASING LLJET HAVE LIMITED THE LOW
LEVEL MOISTURE CONVERGENCE INTO NERN SD AND OUR SOUTHERN FA. SFC
BOUNDARY REMAINS STALLED ACROSS SERN ND INTO NWRN MN... ROUGHLY
ALG AN ABR-FAR-BDE LINE. SOUTH OF THIS BOUNDARY...DEEP CONVECTION
HAS INCREASED FROM ERN SD INTO CNTRL MN. THIS AREA SHUD REMAIN
ACTIVE THROUGHOUT THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 355 AM CDT SUN JUL 14 2013
A SURFACE BOUNDARY IS DRAPED ACROSS THE FA AND EXTENDS FROM A LOW
PRESSURE CENTER IN WRN NE... THROUGH ECNTRL ND INTO NORTHWEST ONT.
DEWPTS FROM THE UPPER 60S TO LOWER 70S CONTINUE TO PILE UP AHEAD
OF THE BOUNDARY... AND WITH A WEAK 850 LLJET EXTENDING UP FROM ERN
SD... SHUD MAINTAIN AN AREA OF +1000 MUCAPE INTO SERN ND AND
PORTIONS OF WCNTRL MN THROUGH THE MORNING.
A CONVECTIVE COMPLEX NOW PUSHING FM NCNTRL SD INTO NERN SD IS
EXPECTED TO DRIVE INTO THIS UNSTABLE AIRMASS AND PERHAPS PENETRATE
TO THE MN BORDER WITH STRONG TO SEVERE WIND POTENTIAL. THE COMPLEX
IS MOVING AWAY FROM ITS AREA OF BEST DEEP LAYER SHEER AND BUMPING
UP AGAINST A SOMEWHAT WARMER MID LEVEL WARM POCKET... SO LONGEVITY
IS IN QUESTION. EXPECT THIS EARLY CONVECTIVE COMPLEX TO WEAKEN
AND DISSIPATE THROUGH MID MORNING.
THAT ALL SAID... H7 TEMPS ARE EXPECTED TO COOL A BIT FURTHER INTO
THIS AFTERNOON OVER SERN ND AND NWRN MN WHILE LOW LEVEL MOISTURE
TRANSPORT KICKS UP A BIT. WITH THIS...AREAS ALONG AND AHEAD OF
THE SURFACE BOUNDARY SHUD DESTABILIZE SIGNIFICANTLY THROUGH EARLY
AFTERNOON AND DEEP CONVECTION INCREASE... FIRST ACROSS THE
SOUTHERN FA AND THEN EXPANDING A BIT NORTHWARD FROM LATE AFTERNOON
INTO THE EVENING.
THIS NOW QUASI STATIONARY BOUNDARY SHUD REMAIN A FOCUS FOR
CONVECTION INTO MONDAY MORNING... SHIFTING SLOWLY NORTHWARD AND
WEAKENING THROUGHOUT THE DAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 355 AM CDT CDT SUN JUL 14 2013
MONDAY NIGHT AND TUESDAY...SOUTHWESTERLY FLOW ALOFT CONTINUES WITH
ANOTHER SHORTWAVE MOVING THROUGH SOUTHERN CANADA. A SFC TROUGH
DEVELOPING OVER THE NORTHERN ROCKIES ON MONDAY WILL HELP PUSH WARM
MOIST AIR BACK INTO THE CWA. HOWEVER...700MB TEMPS WILL ALSO BE ON
THE RISE SO WILL KEEP POPS IN THE 20 TO 30 PERCENT RANGE AS
CAPPING SHOULD MINIMIZE COVERAGE. THE UPPER SHORTWAVE OVER CANADA
MOVES BY TUESDAY AND SHOULD HELP PUSH ANOTHER WEAK FRONTAL
BOUNDARY INTO THE NORTHERN CWA.
TUESDAY NIGHT THROUGH SATURDAY...LONG WAVE UPPER LEVEL RIDGE
EXTENDS FROM THE OH VALLEY TO THE DESERT SOUTHWEST. BETWEEN DAY 5
AND DAY 7 EAST END OF UPPER RIDGE BEGINS TO SHIFT WEST AND SOUTH
AS UPPER TROUGH ROTATES INTO EASTERN CANADA AND THE NEW ENGLAND
STATES. GFS AND ECMWF WERE IN REASONABLE AGREEMENT AT THE
BEGINNING OF THE PERIOD. THE GFS BECOMES FASTER BY THE END OF THE
PERIOD. WILL USE A BLEND OF THE ECMWF AND GFS THIS PERIOD.
WILL TRIM BACK POPS ON THU NIGHT IN NORTHWEST ZONES AND TAKE OUT
PRECIP ON FRI.
TEMPS INCREASED A DEGREE OR TWO FOR WED...FRI AND SAT AND DECREASE A
DEGREE FOR THU FROM YESTERDAYS RUN.
&&
.AVIATION...
FRONTAL BOUNDARY CONTINUES TO WOBBLE AROUND BUT NOT MOVE
MUCH...CONTINUING FROM JUST SOUTHWEST OF KFAR TO AROUND KBDE. THINK
THERE SHOULD BE SOME LIFTING NORTHWARD OF THE FRONT LATER THIS
AFTERNOON AND INTO TONIGHT...WITH KFAR AND KBJI SHOWING SOME
SCATTERED SHRA AND TS...ALONG WITH MVFR CEILINGS AT TIMES UNDER
DEEPER MOISTURE. NORTH OF THE FRONT...KDVL...KGFK AND KTVF HAVE ALL
GONE TO VFR CIGS...AND THIS TREND SHOULD CONTINUE THROUGH THE REST
OF THE TAF PERIOD. REMOVED PRECIP MENTION AS THINK THAT ANY
ACTIVITY WILL BE IN THE GENERAL VICINITY OF THE FRONT AND THAT
SHOULD BE WELL SOUTH OF THOSE TAF SITES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...EWENS
LONG TERM...HOPPES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS AMARILLO TX
310 PM CDT SUN JUL 14 2013
.SHORT TERM...
COLD FRONT NOW THROUGH ALL OF THE PANHANDLES AS OF 3 PM CDT. IN ITS
WAKE...DECREASING TEMPERATURES AND SCATTERED SHOWERS ACROSS.
FOR TONIGHT...SHOULD SEE COVERAGE OF SHOWERS INCREASE A BIT AND HIGH
RESOLUTION MODELS LIKE THE HRRR AND TTU WRF CONTINUE TO SHOW THIS
TREND. WITH VERY LIMITED INSTABILITY...EXPECT THE ACTIVITY TO
PRIMARILY BE LIGHT RAIN SHOWERS...THOUGH AN ISOLATED THUNDERSTORM IS
POSSIBLE.
TOMORROW THROUGH TUESDAY...EXPECT A LULL IN THE PRECIP STARTING SOMETIME
EARLY TOMORROW MORNING AND CONTINUING THROUGH MID DAY AS THE REGION
WILL BE ON THE DRIER NW SIDE OF THE LOW. AS THE LOW CONTINUES TO
SLIDE EAST TOMORROW NIGHT...EXPECT PRECIP TO SPREAD FROM EAST TO WEST
ONCE AGAIN...AS BETTER LIFT IS EXPECTED ON THE EASTERN SIDE OF THE
UPPER LEVEL LOW. STILL SOME QUESTION AS TO HOW FAR NORTH MOISTURE
WILL ADVECT AND IF CONVECTION FURTHER DOWN STATE WILL ROB SOME OF THE
MOISTURE ADVECTION FOR THE PANHANDLES. STILL THINK THE BEST CHANCE
WILL BE TOMORROW NIGHT...WITH CHANCES DECREASING AFTER THAT.
.LONG TERM...
WEDNESDAY THROUGH THURSDAY...COULD STILL SEE SOME LINGERING
CONVECTION EVEN THOUGH THE LOW WILL BE PROPAGATING OVER NORTHERN
MEXICO BY THIS POINT...THE RESULTING MID AND UPPER LEVEL
SOUTHEASTERLY FLOW SHOULD RESULT IN A MOIST FETCH FROM THE GULF.
FRIDAY THROUGH SUNDAY...CONSIDERABLE UNCERTAINTY IN THE UPPER LEVEL
PATTERN THROUGH THIS PERIOD. GFS SHOWS VERY WEAK FLOW OVER THE REGION
THROUGH THIS PERIOD...WITH THE HIGH BUILDING OVER THE WESTERN U.S.
WHILE THE ECMWF SHOWS THE HIGH BUILDING OVER THE ROCKIES THEN SLIDING
SE TOWARDS THE PANHANDLES. EITHER WAY...IT SHOULD BE A DRIER
PATTERN...WITH THE POSSIBLE EXCEPTION OF SOME MOUNTAIN CONVECTION
SLIDING INTO THE NW CORNER ON SATURDAY UNDER VERY WEAK NW FLOW.
JOHNSON
&&
.FIRE WEATHER...
MUCH COOLER WEATHER...RAIN CHANCES...AND RELATIVE HUMIDITY VALUES
WELL ABOVE 20 PERCENT WILL PRECLUDE ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS FOR THE NEXT SEVERAL DAYS.
JOHNSON
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 58 72 57 75 62 / 60 30 50 40 20
BEAVER OK 60 77 59 85 64 / 30 20 20 20 10
BOISE CITY OK 59 74 56 78 58 / 70 20 20 30 10
BORGER TX 63 77 61 78 64 / 60 30 40 40 20
BOYS RANCH TX 62 76 61 76 63 / 70 20 40 40 20
CANYON TX 60 73 58 73 62 / 70 30 50 50 30
CLARENDON TX 59 73 60 77 64 / 60 40 60 40 30
DALHART TX 58 75 57 76 60 / 70 30 30 30 20
GUYMON OK 61 77 59 82 62 / 50 20 20 30 10
HEREFORD TX 60 74 58 72 61 / 70 30 50 50 30
LIPSCOMB TX 60 78 61 82 64 / 40 30 30 30 10
PAMPA TX 58 72 59 77 62 / 50 30 50 40 20
SHAMROCK TX 60 77 61 82 65 / 50 50 50 40 20
WELLINGTON TX 62 78 63 84 67 / 60 50 60 40 30
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
07/16
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1211 PM CDT SUN JUL 14 2013
.AVIATION...
PLEASE SEE DISCUSSION JUST ISSUED BELOW FOR MESOSCALE AND SYNOPITC
SITUATION. AS FOR AVIATION CONCERNS...SCT SHWRS WILL BE ONGOING
THROUGH THIS EVENING AND LIKELY PAST MIDNIGHT ESPECIALLY FOR KAMA.
MOIST UPSLOPE WILL BRING LOW CLOUDS AND MVFR CONDITIONS TO THE TAF
SITES LATER TONIGHT AND PERSIST UNTIL 18Z MONDAY.
&&
.PREV DISCUSSION... /ISSUED 1200 PM CDT SUN JUL 14 2013/
UPDATE...
THE FRONT IS NOW PUSHING INTO THE WESTERN PANHANDLES...HAVING JUST
PASSED AMARILLO AND GUYMON. FOR LOCATIONS EAST OF THE FRONT...THEY
HAVE ALREADY REACHED THE HIGH FOR THE DAY...AS THERE IS GENERALLY A
10 DEGREE OR MORE TEMPERATURE DROP WITH THE FRONT. THUS HAVE UPDATED
TEMPERATURES AND WIND TO REFLECT THIS EARLIER ARRIVAL OF THE FRONT.
ALSO...COVERAGE OF SHOWERS ACROSS THE PANHANDLES HAS INCREASED...AND
BOTH THE HRRR AND THE TTU WRF SHOW THE TREND CONTINUING AS THE FRONT
MOVES FURTHER WEST. THUS...HAVE STARTED MENTION OF PRECIPITATION
ACROSS THE AREA NOW...CONTINUING THROUGH THE REST OF THE AFTERNOON.
JOHNSON
PREV DISCUSSION... /ISSUED 652 AM CDT SUN JUL 14 2013/
AVIATION...
FOR THE 12Z TAFS, WE HAVE A COMPLICATED FORECAST.
HAVE MODERATE TO HIGH CONFIDENCE KAMA AND KDHT WILL HAVE VCTS 23Z-02Z
AND 20Z-01Z, RESPECTIVELY. KGUY COULD BE IMPACTED BY VCTS 20Z-00Z,
BUT CONFIDENCE OF OCCURRENCE IS TOO LOW TO MENTION. IF ANY TERMINAL
IS DIRECTLY IMPACTED BY -TSRA, BRIEF WIND GUSTS UP TO 40 KT AND IFR
CONDITIONS WILL BE POSSIBLE. ALTHOUGH AN ISOLATED -TSRA CAN`T BE
RULED OUT 02Z-08Z, THINK -SHRA WILL BE THE MOST PREVALENT TYPE OF
PRECIPITATION AT ALL TERMINALS.
GUSTY EASTERLY WINDS UP TO 30 KT WILL DEVELOP BEHIND A COLD FRONT
WITH THE STRONGEST WINDS OCCURRING 1930Z-00Z.
VERY HIGH CONFIDENCE THAT ALL TERMINALS WILL EXPERIENCE AT LEAST MVFR
CONDITIONS AFTER 02Z. HAVE MODERATE TO HIGH CONFIDENCE THAT KAMA
WILL SEE IFR (POSSIBLY LIFR) CONDITIONS AFTER 07Z. KDHT AND KGUY
COULD ALSO SEE IFR CONDITIONS AFTER 06Z, BUT CONFIDENCE OF OCCURRENCE
IS A LITTLE TOO LOW TO MENTION AT THIS TIME.
JACKSON
PREV DISCUSSION... /ISSUED 435 AM CDT SUN JUL 14 2013/
DISCUSSION...
BIG CHANGES ARE IN STORE FOR TODAY AND THE START OF THE WORK WEEK AS
AN UNSEASONABLY WESTWARD TRAVELING CLOSED UPPER LEVEL LOW SIGNIFICANTLY
IMPACTS THE WEATHER ACROSS THE REGION.
THE ARRIVAL OF A BACKDOOR COLD FRONT AND SUBSEQUENT CLOUD COVER AND
CONVECTION WILL PLAY A HUGE ROLE IN HIGH TEMPERATURES TODAY MAKING
QUITE A TRICKY FORECAST ESPECIALLY FOR LOCATIONS IN THE CENTRAL AND
EASTERN PANHANDLES. LATEST SHORT RANGE MODELS SUGGEST THAT THE CLOSED
UPPER LOW WILL ARRIVE SLIGHTLY LATER THAN PREVIOUSLY THOUGHT WITH THE
EASTERLY WIND SHIFT NOT OCCURRING IN AMARILLO UNTIL LATE AFTERNOON.
WITH THAT SAID...INCREASED HIGH TEMPERATURES AND DECREASED CHANCES
FOR RAIN ACROSS MUCH OF THE AREA WITH EXCEPTION OF THE FAR EASTERN
PORTIONS OF THE PANHANDLES.
FIRST ROUND OF SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT AS THE
UPPER LOW TRACKS ACROSS THE AREA. HEAVIEST RAIN DOES APPEAR TO OCCUR
JUST SOUTH OF THE PANHANDLES...SO HIGHEST POPS WILL BE ALONG AND
SOUTH OF I-40 AS WELL AS THE FAR WESTERN PANHANDLES...AND THEN DECREASE
AS YOU GO NORTHEAST. SOMEWHAT OF A LULL LOOKS TO TAKE PLACE DURING
THE DAY ON MONDAY BEFORE ANOTHER IMPULSE WRAPS AROUND THE UPPER LOW
GIVING THE AREA ROUND TWO OF CONVECTION LATE MONDAY INTO MONDAY
NIGHT...AND LIKELY CONTINUING INTO EARLY TUESDAY. THIS TIME FRAME
LOOKS TO BE THE BEST CHANCES FOR THE HEAVIEST PRECIPITATION FOR THE
AREA BUT ONCE AGAIN THE HIGHEST POPS WILL BE ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA.
AS FAR AS TEMPERATURES ON MONDAY AND TUESDAY...HIGHS STILL LOOK ON
TRACK TO ONLY REACH THE 70S ON BOTH DAYS WITH A FEW 80 DEGREE
READINGS POSSIBLE IN THE DRIER OKLAHOMA PANHANDLE. STILL QUITE
CONFIDENT THAT AMARILLO WILL SHATTER THE LOW MAXIMUM TEMPERATURE
RECORD ON MONDAY (79 IN 1898) WITH THE CURRENT FORECAST OF 74
DEGREES. LOW TEMPERATURES WILL BE UNSEASONABLY COOL AS WELL WITH LOWS
IN THE 50S.
AS THE UPPER LOW MOVES SOUTHWEST AWAY FROM THE REGION...ITS IMPACTS
WILL NOT BE QUITE AS PROMINENT OVER THE AREA. REGARDLESS...THINK
THERE WILL BE ENOUGH MOISTURE ALONG WITH A FEW UPPER LEVEL IMPULSES
AROUND TO CONTINUE DEVELOPING CONVECTION OVER THE AREA TUESDAY
NIGHT THROUGH POSSIBLY THURSDAY...BUT RAINFALL CHANCES REALLY LOOK
MUCH LOWER AND CONFINED TO THE TEXAS PANHANDLE...AND MOSTLY THE
SOUTHERN PORTIONS. HIGH TEMPERATURES WILL REBOUND BACK INTO THE 80S
WEDNESDAY AND THURSDAY WITH THE 90S RETURNING TO THE OKLAHOMA
PANHANDLE.
MOSTLY DRY WEATHER RETURNS FRIDAY AND THE WEEKEND WITH EXCEPTION OF
THE EXTREME NORTHWEST PORTIONS OF THE PANHANDLES AS SOME DIURNAL
CONVECTION COULD DEVELOP OFF OF THE HIGHER TERRAN OVER SOUTHEAST
COLORADO AND NORTHEAST NEW MEXICO. BEST RAIN CHANCES APPEAR TO BE
SATURDAY AND ESPECIALLY SUNDAY ALTHOUGH THINK MOST AREAS WILL REMAIN
DRY. TEMPERATURES RETURN BACK TO SEASONAL NORMALS WITH HIGHS IN THE
90S AND LOWS N THE 60S.
KNS
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH AT LEAST TUESDAY AS MINIMUM AFTERNOON RELATIVE HUMIDITIES
WILL BE ABOVE 20 PERCENT...AND THE 20 FOOT WIND SPEEDS WILL REMAIN AT
OR BELOW 20 MPH. HOWEVER...AN ABRUPT SHIFT TO EASTERLY WINDS OF 20 TO
30 MPH WITH HIGHER GUSTS IS EXPECTED THIS AFTERNOON AS A BACKDOOR COLD
FRONT MOVES WEST ACROSS THE AREA. CHANCES FOR THUNDERSTORMS WILL
INCREASE LATE THIS AFTERNOON AND CONTINUE THROUGH WEDNESDAY ALLOWING
WETTING RAINS TO LIMIT ELEVATED AND CRITICAL FIRE WEATHER CONDITIONS.
KNS
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
07/16
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1200 PM CDT SUN JUL 14 2013
.UPDATE...
THE FRONT IS NOW PUSHING INTO THE WESTERN PANHANDLES...HAVING JUST
PASSED AMARILLO AND GUYMON. FOR LOCATIONS EAST OF THE FRONT...THEY
HAVE ALREADY REACHED THE HIGH FOR THE DAY...AS THERE IS GENERALLY A
10 DEGREE OR MORE TEMPERATURE DROP WITH THE FRONT. THUS HAVE UPDATED
TEMPERATURES AND WIND TO REFLECT THIS EARLIER ARRIVAL OF THE FRONT.
ALSO...COVERAGE OF SHOWERS ACROSS THE PANHANDLES HAS INCREASED...AND
BOTH THE HRRR AND THE TTU WRF SHOW THE TREND CONTINUING AS THE FRONT
MOVES FURTHER WEST. THUS...HAVE STARTED MENTION OF PRECIPITATION
ACROSS THE AREA NOW...CONTINUING THROUGH THE REST OF THE AFTERNOON.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT SUN JUL 14 2013/
AVIATION...
FOR THE 12Z TAFS, WE HAVE A COMPLICATED FORECAST.
HAVE MODERATE TO HIGH CONFIDENCE KAMA AND KDHT WILL HAVE VCTS 23Z-02Z
AND 20Z-01Z, RESPECTIVELY. KGUY COULD BE IMPACTED BY VCTS 20Z-00Z,
BUT CONFIDENCE OF OCCURRENCE IS TOO LOW TO MENTION. IF ANY TERMINAL
IS DIRECTLY IMPACTED BY -TSRA, BRIEF WIND GUSTS UP TO 40 KT AND IFR
CONDITIONS WILL BE POSSIBLE. ALTHOUGH AN ISOLATED -TSRA CAN`T BE
RULED OUT 02Z-08Z, THINK -SHRA WILL BE THE MOST PREVALENT TYPE OF
PRECIPITATION AT ALL TERMINALS.
GUSTY EASTERLY WINDS UP TO 30 KT WILL DEVELOP BEHIND A COLD FRONT
WITH THE STRONGEST WINDS OCCURRING 1930Z-00Z.
VERY HIGH CONFIDENCE THAT ALL TERMINALS WILL EXPERIENCE AT LEAST MVFR
CONDITIONS AFTER 02Z. HAVE MODERATE TO HIGH CONFIDENCE THAT KAMA
WILL SEE IFR (POSSIBLY LIFR) CONDITIONS AFTER 07Z. KDHT AND KGUY
COULD ALSO SEE IFR CONDITIONS AFTER 06Z, BUT CONFIDENCE OF OCCURRENCE
IS A LITTLE TOO LOW TO MENTION AT THIS TIME.
JACKSON
PREV DISCUSSION... /ISSUED 435 AM CDT SUN JUL 14 2013/
DISCUSSION...
BIG CHANGES ARE IN STORE FOR TODAY AND THE START OF THE WORK WEEK AS
AN UNSEASONABLY WESTWARD TRAVELING CLOSED UPPER LEVEL LOW SIGNIFICANTLY
IMPACTS THE WEATHER ACROSS THE REGION.
THE ARRIVAL OF A BACKDOOR COLD FRONT AND SUBSEQUENT CLOUD COVER AND
CONVECTION WILL PLAY A HUGE ROLE IN HIGH TEMPERATURES TODAY MAKING
QUITE A TRICKY FORECAST ESPECIALLY FOR LOCATIONS IN THE CENTRAL AND
EASTERN PANHANDLES. LATEST SHORT RANGE MODELS SUGGEST THAT THE CLOSED
UPPER LOW WILL ARRIVE SLIGHTLY LATER THAN PREVIOUSLY THOUGHT WITH THE
EASTERLY WIND SHIFT NOT OCCURRING IN AMARILLO UNTIL LATE AFTERNOON.
WITH THAT SAID...INCREASED HIGH TEMPERATURES AND DECREASED CHANCES
FOR RAIN ACROSS MUCH OF THE AREA WITH EXCEPTION OF THE FAR EASTERN
PORTIONS OF THE PANHANDLES.
FIRST ROUND OF SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT AS THE
UPPER LOW TRACKS ACROSS THE AREA. HEAVIEST RAIN DOES APPEAR TO OCCUR
JUST SOUTH OF THE PANHANDLES...SO HIGHEST POPS WILL BE ALONG AND
SOUTH OF I-40 AS WELL AS THE FAR WESTERN PANHANDLES...AND THEN DECREASE
AS YOU GO NORTHEAST. SOMEWHAT OF A LULL LOOKS TO TAKE PLACE DURING
THE DAY ON MONDAY BEFORE ANOTHER IMPULSE WRAPS AROUND THE UPPER LOW
GIVING THE AREA ROUND TWO OF CONVECTION LATE MONDAY INTO MONDAY
NIGHT...AND LIKELY CONTINUING INTO EARLY TUESDAY. THIS TIME FRAME
LOOKS TO BE THE BEST CHANCES FOR THE HEAVIEST PRECIPITATION FOR THE
AREA BUT ONCE AGAIN THE HIGHEST POPS WILL BE ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA.
AS FAR AS TEMPERATURES ON MONDAY AND TUESDAY...HIGHS STILL LOOK ON
TRACK TO ONLY REACH THE 70S ON BOTH DAYS WITH A FEW 80 DEGREE
READINGS POSSIBLE IN THE DRIER OKLAHOMA PANHANDLE. STILL QUITE
CONFIDENT THAT AMARILLO WILL SHATTER THE LOW MAXIMUM TEMPERATURE
RECORD ON MONDAY (79 IN 1898) WITH THE CURRENT FORECAST OF 74
DEGREES. LOW TEMPERATURES WILL BE UNSEASONABLY COOL AS WELL WITH LOWS
IN THE 50S.
AS THE UPPER LOW MOVES SOUTHWEST AWAY FROM THE REGION...ITS IMPACTS
WILL NOT BE QUITE AS PROMINENT OVER THE AREA. REGARDLESS...THINK
THERE WILL BE ENOUGH MOISTURE ALONG WITH A FEW UPPER LEVEL IMPULSES
AROUND TO CONTINUE DEVELOPING CONVECTION OVER THE AREA TUESDAY
NIGHT THROUGH POSSIBLY THURSDAY...BUT RAINFALL CHANCES REALLY LOOK
MUCH LOWER AND CONFINED TO THE TEXAS PANHANDLE...AND MOSTLY THE
SOUTHERN PORTIONS. HIGH TEMPERATURES WILL REBOUND BACK INTO THE 80S
WEDNESDAY AND THURSDAY WITH THE 90S RETURNING TO THE OKLAHOMA
PANHANDLE.
MOSTLY DRY WEATHER RETURNS FRIDAY AND THE WEEKEND WITH EXCEPTION OF
THE EXTREME NORTHWEST PORTIONS OF THE PANHANDLES AS SOME DIURNAL
CONVECTION COULD DEVELOP OFF OF THE HIGHER TERRAN OVER SOUTHEAST
COLORADO AND NORTHEAST NEW MEXICO. BEST RAIN CHANCES APPEAR TO BE
SATURDAY AND ESPECIALLY SUNDAY ALTHOUGH THINK MOST AREAS WILL REMAIN
DRY. TEMPERATURES RETURN BACK TO SEASONAL NORMALS WITH HIGHS IN THE
90S AND LOWS N THE 60S.
KNS
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH AT LEAST TUESDAY AS MINIMUM AFTERNOON RELATIVE HUMIDITIES
WILL BE ABOVE 20 PERCENT...AND THE 20 FOOT WIND SPEEDS WILL REMAIN AT
OR BELOW 20 MPH. HOWEVER...AN ABRUPT SHIFT TO EASTERLY WINDS OF 20 TO
30 MPH WITH HIGHER GUSTS IS EXPECTED THIS AFTERNOON AS A BACKDOOR COLD
FRONT MOVES WEST ACROSS THE AREA. CHANCES FOR THUNDERSTORMS WILL
INCREASE LATE THIS AFTERNOON AND CONTINUE THROUGH WEDNESDAY ALLOWING
WETTING RAINS TO LIMIT ELEVATED AND CRITICAL FIRE WEATHER CONDITIONS.
KNS
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
07/16
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
250 PM CDT SUN JUL 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
MAIN FORECAST CONCERN IS ON THUNDERSTORM POTENTIAL FOR MONDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHARP SHORTWAVE TROUGH OVER BRITISH COLUMBIA...AN UPPER LOW
OVER EASTERN OKLAHOMA...A SHORTWAVE TROUGH STRETCHING FROM NORTHERN
MN INTO EASTERN SOUTH DAKOTA...AND THE BERMUDA HIGH OVER THE EASTERN
GREAT LAKES. 500MB HEIGHTS ASSOCIATED WITH THE BERMUDA HIGH ARE
QUITE IMPRESSIVE...NEARING 600 DAM OR 2.5 STANDARD DEVIATIONS ABOVE
NORMAL. DESPITE THE SUBSTANTIAL 500MB HEIGHTS...850MB TEMPS ARE ONLY
IN THE 15-18C UNDERNEATH IT PER 12Z RAOBS OR NEAR 1 STANDARD
DEVIATION ABOVE NORMAL. THE WESTERN EXTENT OF THE SUBTROPICAL RIDGE
HAS BEEN PROVIDING SUBSIDENCE OVER THE FORECAST AREA...RESULTING IN
DRY CONDITIONS WITH JUST SOME DIURNAL CUMULUS CLOUDS. TO OUR
WEST...A STREAM OF PRECIPITABLE WATER VALUES OF 1.65 TO 2 INCHES
PER GOES DERIVED IMAGERY STRETCHED FROM CENTRAL OKLAHOMA TO
EASTERN SOUTH DAKOTA AND NORTHERN MN. THIS STREAM OF HIGH MOISTURE
IS CO-LOCATED WITH THAT SHORTWAVE TROUGH IN THE NORTHERN PLAINS
AND DEFORMATION ON THE WEST SIDE OF THE UPPER LOW. NUMEROUS
SHOWERS AND THUNDERSTORMS WERE PRESENT IN THE STREAM.
EXPECT THE RETROGRADING 500MB PATTERN TO CONTINUE THROUGH THE SHORT
TERM PERIOD...SUCH THAT BY 00Z TUESDAY MODELS FORECAST THE BERMUDA
HIGH TO BE SITUATED NEAR THE OHIO/INDIANA BORDER. THIS RETROGRESSION
MEANS 500MB HEIGHTS ARE GOING TO RISE OVER THE FORECAST AREA...
IMPLYING SUBSIDENCE. NOT ANTICIPATING ANY PRECIPITATION TONIGHT
BEING IN THE NOCTURNAL COOLING PERIOD AND RISING HEIGHTS ALOFT. ON
MONDAY...DESPITE BEING UNDER THE SUBSIDENCE OF THE RISING HEIGHTS
ALOFT...NEARLY EVERY MODEL DEPICTS ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT BETWEEN 18Z-00Z OVER THE FORECAST AREA.
THE REASONING FOR THE PRECIPITATION IS A COMBINATION OF FACTORS:
1. SOUTHEAST WINDS ADVECTING IN 70+ SURFACE DEWPOINTS...WHICH ARE
ACCOMPANYING THE BERMUDA HIGH AND ENHANCED BY EVAPOTRANSPORATION
FROM VEGETATION.
2. STREAM OF HIGHER PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES
COMING UP OUT OF GEORGIA AND ALABAMA CURRENTLY.
3. DAYTIME HEATING COMBINING WITH THE HIGHER DEWPOINTS TO BUILD UP
INSTABILITY. MIXING TO 850MB TEMPS OF 16-17C SHOULD YIELD HIGHS IN
THE MID TO UPPER 80S.
4. SOUNDINGS DEPICT NO CAPPING
LOOKING AT VARIOUS PRESSURE LEVELS FOR CONVERGENCE...IT IS VERY
DIFFICULT TO FIND ANY. THUS...IT APPEARS THE LACK OF CAPPING AND THE
HIGHER DEEPER MOISTURE ITSELF WILL RESULT IN POP UP SHOWERS AND
THUNDERSTORMS. 0-6KM SHEAR VALUES OF LESS THAN 20 KT MEANS THESE
STORMS ARE GOING TO BE PULSE AND NON-SEVERE...WITH OUTFLOWS
PRODUCING ADDITIONAL SHOWERS AND THUNDERSTORMS. MAIN CONCERN WITH
THIS PRECIPITATION IS BRIEF HEAVY RAIN GIVEN THE PRECIPITABLE WATER
VALUES AND DEEP WARM CLOUD DEPTHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
THE RETROGRESSION 500MB PATTERN CONTINUES FROM THE SHORT TERM PERIOD
RIGHT INTO NEXT WEEKEND. 14.12Z ECMWF/CANADIAN/GFS AND 14.00Z ECMWF
ENSEMBLE MEAN ALL SHOW THAT THE BERMUDA HIGH WILL SLOWLY MOVE
WESTWARD THROUGH THE WEEK...SUCH THAT BY LATE FRIDAY INTO THE
WEEKEND TROUGHING DOMINATES MUCH OF CANADA INTO THE WESTERN GREAT
LAKES REGION.
MONDAY NIGHT THROUGH WEDNESDAY...
CONVECTION THAT FORMED MONDAY AFTERNOON SHOULD DISSIPATE PRETTY
QUICK IN THE EVENING...LIKELY BY 03Z...AS THE LOSS OF DAYTIME
HEATING DIMINISHES THE INSTABILITY. THE REST OF THE NIGHT INTO
TUESDAY MORNING LOOKS DRY WITH THE MAIN FORCING FOR NOCTURNAL
CONVECTION WELL OFF TO THE NORTHWEST IN THE DAKOTAS. A SIMILAR SETUP
TO MONDAY AFTERNOON LOOKS TO OCCUR FOR TUESDAY AFTERNOON WITH
DEWPOINTS IN THE UPPER 60S TO LOW 70S...HIGHS A FEW DEGREES WARMER
GIVEN 850MB TEMPS PROGGED BETWEEN 18-19C...AND HIGHER CAPE VALUES
DUE TO THESE READINGS. HOWEVER...MODELS ARE MUCH LESS AGGRESSIVE
WITH QPF...AND THIS APPEARS TO STEM FROM PRECIPITABLE WATER VALUES
THAT ARE 0.25-0.5 INCH LOWER. GIVEN THAT THE 14.12Z NAM WHICH IS
USUALLY AGGRESSIVE IN THESE SCENARIOS AND HAPPENS TO BE DRY...AND
COLLABORATION WITH SURROUNDING OFFICES...WENT DRY FOR TUESDAY.
SHOWERS AND THUNDERSTORMS STILL LOOK POSSIBLE NORTH AND EAST OF THE
FORECAST AREA...ASSOCIATED WITH LAKE BREEZES RUNNING INTO THE
UNSTABLE AIR. A COMPLETE REPEAT OF THE WEATHER HAPPENS TUESDAY NIGHT
AND WEDNESDAY...AND HERE AGAIN MODELS ARE NOT THAT AGGRESSIVE WITH
QPF WEDNESDAY AFTERNOON STEMMING FROM SIMILAR PRECIPITABLE WATER
VALUES TO TUESDAY. REMOVED THE 20 PERCENT CHANCES FOR WEDNESDAY.
SAFE TO SAY THAT IF INDEED NO PRECIPITATION HAPPENS TUESDAY...
WEDNESDAY WILL END UP DRY TOO. HIGHS ON WEDNESDAY ARE LIKELY TO BE
SIMILAR TO TUESDAY WITH 850MB TEMPS HOVERING AROUND 19C...YIELDING
READINGS IN THE UPPER 80S TO LOWER 90S.
WITH TUESDAY AND WEDNESDAY AFTERNOON DEWPOINTS IN THE UPPER 60S TO
LOWER 70S AND HIGHS IN UPPER 80S TO LOWER 90S...HEAT INDICES ARE
LIKELY TO CLIMB INTO THE 95-100 RANGE. THESE ARE JUST UNDER HEAT
ADVISORY CRITERIA. SHOULD EITHER DEWPOINTS OR TEMPERATURES GET
HIGHER THAN FORECAST...HEAT ADVISORIES MAY BE REQUIRED.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE PROGGED SWITCH IN THE UPPER FLOW TO MORE NORTHWESTERLY ALLOWS
A COLD FRONT SITUATED OVER NORTHERN MN AND UPPER MI ON WEDNESDAY
TO SLOWLY DRIFT SOUTH. THE TIMING OF WHEN THIS BOUNDARY CROSSES
THE FORECAST AREA LOOKS TO BE MODULATED BY A SHORTWAVE DROPPING
THROUGH NORTH DAKOTA...WHICH COULD STALL OR EVEN SEND THE FRONT
BACK NORTHWARD THURSDAY NIGHT AS SUGGESTED BY THE 14.00Z/14.12Z
ECMWF. MOST MODELS AGREE ON A TIMING OF THE COLD FRONT CROSSING
THE AREA FRIDAY INTO FRIDAY EVENING...WITH PERHAPS THE FRONT
COMING INTO NORTHERN SECTIONS OF THE FORECAST AREA WEDNESDAY
NIGHT. GIVEN PLENTIFUL INSTABILITY IN PLACE AHEAD OF AND AROUND
THE BOUNDARY...AS WELL AS A PLUME OF HIGHER PRECIPITABLE WATER
VALUES ON THE ORDER OF 1.75-2 INCHES...DEFINITELY NEED CHANCES OF
SHOWERS AND THUNDERSTORMS. THERE ARE INDICATIONS OF POSSIBLE MCS
ACTIVITY TOO...ESPECIALLY THURSDAY AFTERNOON AND NIGHT NORTH OF
I-90 WHICH IS WHERE CHANCES OF PRECIPITATION ARE ON THE ORDER OF
50-60. ONE PORTION OF THE FORECAST WHERE CHANCES MAY BE ABLE TO BE
REMOVED IS FRIDAY NIGHT...SINCE THERE ARE SOME INDICATIONS OF THE
FRONT AND ASSOCIATED CONVECTION GETTING OUT OF THE AREA IN TIME.
HIGH PRESSURE BUILDS IN FOR SATURDAY AND SATURDAY NIGHT...BRINGING
DRIER CONDITIONS. UNCERTAINTY INCREASES FOR SUNDAY WITH
INDICATIONS OF SOME SHORTWAVE TROUGH DROPPING THROUGH IN THE
NORTHWEST FLOW. HAVE FOLLOWED A MODEL CONSENSUS OF 20-40 PERCENT
CHANCES FOR NOW.
SOME SEVERE WEATHER IS POSSIBLE THURSDAY THROUGH FRIDAY...WITH 0-6KM
SHEAR VALUES PROGGED OF 30-35 KT ALONG THE COLD FRONT. DAMAGING
WINDS AND HEAVY RAIN WOULD APPEAR TO BE THE MAIN HAZARDS. LOCATIONS
NORTH OF I-90 SEEM TO BE CENTERED ON HAVING THE MOST RAIN DURING
THIS PERIOD...WHICH IS AN AREA THAT NOT ONLY CAN HANDLE THE RAIN BUT
NEEDS IT.
TEMPERATURES THURSDAY THROUGH FRIDAY ARE QUITE TRICKY. 850MB TEMPS
UPWARDS OF 20C COULD EASILY SUPPORT HIGHS IN THE LOW TO EVEN PERHAPS
MID 90S...AND WITH DEWPOINTS UP IN THE LOW 70S WOULD YIELD HEAT
INDICES AGAIN IN THE 95-100 RANGE. HOWEVER...THERE IS CONVECTION TO
WORRY ABOUT...ESPECIALLY ON FRIDAY. THUS...HIGH TEMPERATURES ARE
ONLY FORECAST IN THE MID 80S TO LOW 90S AT THIS TIME. 850MB TEMPS
FALLING INTO THE 13-15C RANGE FOR SATURDAY AND ONLY CLIMBING ABOUT
1C HIGHER ON SUNDAY WILL RESULT IN COOLER TEMPERATURES...UPPER 70S
TO MID 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1230 PM CDT SUN JUL 14 2013
MORE LOW LEVEL MOISTURE HAS WORKED IN AS DRIER AREAS ARE SHUNTED OR
SQUEEZED OUT FOR THE TIME BEING. THIS HAS RESULTED IN WIDESPREAD
CUMULUS DEVELOPMENT THAT COULD ACTUALLY PRODUCE SOME VFR CEILINGS
FOR A TIME THIS AFTERNOON BEFORE THEY DISSIPATE EARLY THIS EVENING.
HIGHER DEW POINTS COULD ALSO LEAD TO MORE LIGHT FOG OVERNIGHT WITH
SOME AREAS REACHING MVFR CONDITIONS FOR A FEW HOURS BEFORE DAYBREAK
MONDAY. FOG COULD BE MORE DENSE IN SOUTHWEST AND CENTRAL WISCONSIN
IN FAVORED VALLEYS.
MORE DIURNAL CUMULUS EXPECTED MONDAY...AND PERHAPS EVEN ENOUGH
INSTABILITY FOR A FEW POP UP SHOWERS BUT WILL NOT INTRODUCE INTO
TAFS THAT FAR OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1230 PM CDT SUN JUL 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR TODAY IS ON TEMPERATURES AND CLOUD COVER AS
UPPER LEVEL RIDGING PUSHES IN FROM THE EAST.
CURRENTLY...SOME SCATTERED CONVECTION HAS DEVELOPED ALONG THE
DEFORMATION BAND OF A WEAK 500MB TROUGH THAT EXTENDS FROM
NORTHWEST WISCONSIN DOWN INTO WESTERN IOWA. EXTENSIVE MID TO UPPER
LEVEL CLOUD COVER COMES WITH THIS BAND AND HAS BEEN SLOW TO SHIFT
TO THE WEST THIS MORNING. THE 14.06Z RAP 700-400MB RH FIELDS SEEM
TO HAVE A GOOD HANDLE ON THIS CLOUD COVER AND DOES CONTINUE TO
SHIFT THIS CLOUD DECK AND CONVECTION TO THE WEST QUICKLY THIS
MORNING.
HIGH TEMPERATURES FOR TODAY ARE THE NEXT QUESTION AS MUCH OF THE
REGION SHOULD HAVE FULL SUN. 14.06Z RAP AND 14.00Z NAM/GFS
SOUNDINGS INDICATE THAT THE HIGHEST POSSIBLE MIXING WOULD COME
FROM AROUND 875-850MB. WHEN MIXING DOWN A PARCEL FROM THAT LEVEL
OR LOWER...IT SHOWS THAT HIGHS TODAY HAVE A MAX OUT IN THE MID TO
UPPER 80S. MAY SEE SOME FAIR WEATHER CU FORMING BUT THE LOW LEVEL
MOISTURE DOES NOT REALLY START RAMPING UP UNTIL MONDAY...SO THINK
THAT IT WILL BE FEW AND FAR BETWEEN FOR ANY OF THAT DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 322 AM CDT SUN JUL 14 2013
THE MAIN FOCUS FOR THE UPCOMING WEEK IS WITH THE CHANCES FOR RAIN
ALONG WITH DAILY TEMPERATURES.
DESPITE A MAINLY SUBSIDENT ENVIRONMENT MONDAY THROUGH
WEDNESDAY...INCREASING LOW LEVEL MOISTURE WILL LEAD TO A MORE HUMID
AIR MASS THAT WILL HAVE THE POTENTIAL OF PRODUCING SOME VERY ISOLATED
SHOWERS AND THUNDERSTORMS. CONFIDENCE IS NOT VERY HIGH WITH WHETHER
THEY WILL EVEN DEVELOP BASED ON THE LACK OF A FORCING
MECHANISM...BUT GUIDANCE HAS BEEN CONSISTENT WITH SHOWING SOME
PRECIPITATION FORMING IN THE AFTERNOON DURING DIURNAL PEAK HEATING.
HAVE DECIDED TO HONOR THIS WITH SOME 20 PERCENT CHANCES OF
PRECIPITATION MONDAY/TUESDAY/WEDNESDAY AFTERNOON AS A RESULT. ANY
DEEP LAYER SHEAR IS NON-EXISTENT...SO THIS WILL BE PULSEY/CELLULAR
CONVECTION THAT IS BRIEF AND NON- SEVERE.
THE HIGHER CHANCES FOR PRECIPITATION WILL COME LATER IN THE WEEK
AS A COLD FRONT SAGS SOUTH FROM ALONG THE US/CANADIAN BORDER. THE
14.00Z GFS/ECMWF/GEM ALL ANGLE THIS FRONT FROM NEAR FARGO TO THE
EAST TOWARD NORTH CENTRAL WISCONSIN ON THURSDAY WITH CONVECTION
EXPECTED TO DEVELOP ALONG THIS REGION. THE FRONT IS THEN EXPECTED
TO GET A PUSH TO THE SOUTH FRIDAY INTO SATURDAY WITH THE GFS BEING
MUCH MORE WIDESPREAD ON ITS PRECIPITATION WHEN COMPARED TO THE
LATEST ECMWF RUN. HOWEVER...THE TIMING OF THIS FROPA STILL LOOKS
FAIRLY CONSISTENT BETWEEN THESE MODELS...SO HAVE SOME ABOVE
AVERAGE CONFIDENCE IN THE TIMING OF THE HIGHEST PROBABILITIES OF
PRECIPITATION BASED ON THIS FROPA.
LOW LEVEL TEMPERATURES APPEAR TO CLIMB GRADUALLY THROUGH THE WEEK
WITH 850MB TEMPERATURES JUMPING FROM AROUND +16C TODAY TO +20C BY
THURSDAY NIGHT AND 925MB TEMPERATURES GOING FROM +21C TODAY TO
+27C BY THURSDAY NIGHT. WITH MAINLY SUNNY SKIES...TEMPERATURES
SHOULD BE ABLE TO REACH 90F TUESDAY THROUGH THURSDAY AND PERHAPS
FRIDAY IF THE FRONT TAKES LONGER TO GET THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1230 PM CDT SUN JUL 14 2013
MORE LOW LEVEL MOISTURE HAS WORKED IN AS DRIER AREAS ARE SHUNTED OR
SQUEEZED OUT FOR THE TIME BEING. THIS HAS RESULTED IN WIDESPREAD
CUMULUS DEVELOPMENT THAT COULD ACTUALLY PRODUCE SOME VFR CEILINGS
FOR A TIME THIS AFTERNOON BEFORE THEY DISSIPATE EARLY THIS EVENING.
HIGHER DEW POINTS COULD ALSO LEAD TO MORE LIGHT FOG OVERNIGHT WITH
SOME AREAS REACHING MVFR CONDITIONS FOR A FEW HOURS BEFORE DAYBREAK
MONDAY. FOG COULD BE MORE DENSE IN SOUTHWEST AND CENTRAL WISCONSIN
IN FAVORED VALLEYS.
MORE DIURNAL CUMULUS EXPECTED MONDAY...AND PERHAPS EVEN ENOUGH
INSTABILITY FOR A FEW POP UP SHOWERS BUT WILL NOT INTRODUCE INTO
TAFS THAT FAR OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....SHEA