Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/11/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
210 PM MST SAT AUG 9 2014
.SYNOPSIS...
MOISTURE LEVELS ARE ON THE UPSWING AND WILL BE IMPROVING CHANCES FOR
MONSOON RAIN THIS WEEKEND AND THROUGH WEDNESDAY IN AFTERNOON AND
EARLY EVENING PERIOD. TEMPERATURES WILL REMAIN NEAR NORMAL LEVELS.
DRIER CONDITIONS EXPECTED BEGINNING THURSDAY.
&&
.DISCUSSION...
VISIBLE SATELLITE IMAGERY IS SHOWING SCATTERED TO BROKEN MID LEVEL
AC CLOUDS ADVECTING NORTHWARD ACROSS MUCH OF MARICOPA COUNTY AND
WESTERN PINAL COUNTY. DEW POINTS ARE BACK UP TO MODERATE MONSOON
LEVELS WITH MOST SURFACE STATIONS REPORTING IN THE LOW 60S...ABOUT A
20 DEG BUMP FROM FRIDAYS READINGS. ALREADY THIS AFTERNOON STARTING
TO SEE SOME BUILDUPS ALONG THE RIM AND WHITE MTNS WITH SOME
LIGHTNING STRIKES...ANOTHER SIGN THAT THE MONSOON IS BACK WITH US
FOR THE TIME BEING. WATER VAPOR STILL REFLECTING THE RATHER DRY
UPPER LEVEL AND WESTERLY FLOW...WHICH IS ALSO SHOWN ON THE MORNING
SOUNDING FROM PHOENIX.
HAVE NOTICED A FEW WEAK SHOWERS IN THE PHOENIX METRO AFTER REVIEWING
LOCAL WEBCAMS AND RADAR IMAGERY. MOST HAVE BEEN IN THE WEST VALLEY
OR NEAR SOUTH MOUNTAIN. WITH THAT INFORMATION AT HAND...AND THE
INCREASING AVAILABLE MOISTURE THE AFTERNOON POPS WERE BUMPED UP A
BIT...GIVING THE GREATER PHOENIX AREA SLIGHT CHANCES FOR THIS
AFTERNOON AND EVENING.
THE HRRR MESOSCALE MODEL IS CALLING FOR A MCV TO GENERATE JUST SOUTH
OF THE MEXICO BORDER NEAR NOGALES. INDEED...WE ARE ALREADY SEEING
SOME CONVECTIVE BLOWUPS ALONG THE BORDER THIS AFTERNOON. THE MODEL
ALSO INDICATES A VERY PRONOUNCED AND STRONG OUTFLOW BOUNDARY WHICH
IS PROGGED TO MOVE TOWARDS THE NORTH THROUGH PIMA COUNTY AND MAY
POSSIBLY SLIP INTO OUR AREA OF SOUTHWEST MARICOPA AND WESTERN PINAL
COUNTY AROUND 06Z TONIGHT. BASED ON THAT...I DID ADD A BIT OF
BLOWING DUST INTO THE FORECAST FOR THOSE AREAS LATE TONIGHT. WE WILL
HAVE TO SEE IF THAT COMES TO FRUITION.
THE MODELS ARE CONSISTENTLY INDICATING MODERATE MONSOON CONDITIONS
THROUGH AT LEAST TUESDAY WITH MOISTURE STAYING IN PLACE AND THAT
RIDGE REMAINING ANCHORED FROM UTAH THROUGH TEXAS AND THE GOM. THIS
SHOULD ALLOW SUFFICIENT FEEDING FOR THE SOUTHWEST MONSOON ACROSS
ARIZONA AND SOUTHEAST CALIFORNIA. BEGINNING WEDNESDAY...THE HIGH
BEGINS TO BUILD IN MORE OVER WEST TEXAS AND SOUTHERN NEW MEXICO AND
WILL START TO CUT OFF SOME OF THAT MOISTURE. BY FRIDAY THE RIDGE
WILL BE ZONAL...STRETCHING FROM BAJA CA ACROSS THE MEXICO BORDERS OF
AZ AND NM AND OVER TEXAS. IN THE MEANTIME THOUGH...LOOKS LIKE
MODERATE MONSOON ACTIVITY WILL BE IN PLACE FOR THE NEXT FOUR DAYS.
TEMPERATURES WILL REMAIN AT OR EVEN BELOW NORMALS...DEPENDING ON
EXISTENCE OF ANY DEBRIS CLOUDS FROM ERODING MONSOON STORMS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL
A BATCH OF SCT-BKN MID CLOUDS...BASES AOA 12 KFT MSL...WITH ISOLATED
SPRINKLES...WILL LINGER THROUGH AT LEAST 00Z. ISOLATED TO
SCATTERED TSTMS OVER NORTHERN AND SOUTHEAST ARIZONA WILL CONTINUE TO
DEVELOP THE REST OF THE AFTERNOON. ANTICIPATE AT LEAST ONE OUTFLOW
FROM DISTANT STORMS TO MOVE INTO THE PHOENIX AREA AFTER 02Z. TOO
EARLY TO TELL JUST HOW MANY OR HOW STRONG THEY WILL BE. IF SOUTHEAST
ARIZONA STAYS QUIET THEN THERE MAY NOT BE ANY STRONG OUTFLOWS
AFFECTING PHOENIX AREA TAFS TONIGHT. HOWEVER...IF SOUTHEAST ARIZONA
HAS LATE BLOOMING STORMS THAT GET INTO PINAL COUNTY AND SOUTHWEST
MARICOPA COUNTY THEN MORE LIKELY TO SEE SIGNIFICANT OUTFLOWS. IN
TURN THERE WOULD BE POTENTIAL FOR TSTM DEVELOPMENT AT THE TAF SITES.
STORMS OVER SOUTHERN YAVAPAI AND NORTHERN GILA COUNTY COULD ALSO
SEND AN OUTFLOW INTO PHOENIX AREA. HOWEVER...STEERING FLOW NOT
FAVORABLE FOR THEM TO ENCROACH ON VALLEY FLOOR. IN SHORT...NOT
LOOKING FOR AN ACTIVE NIGHT BUT THERE IS SUFFICIENT MOISTURE THAT
STORMS CANNOT BE RULED OUT. CONFIDENCE TOO LOW AT ANY GIVEN AIRFIELD
TO INSERT TSRA IN THE TAF.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL...AND
KBLH...
SOUTH AND SOUTHEAST WINDS WILL PREVAIL THROUGH SUNDAY...LOCALLY
WESTERLY OVER WESTERN IMPERIAL COUNTY. THUNDERSTORMS...IF ANY...ARE
EXPECTED TO REMAIN EAST OF THE LOWER COLORADO RIVER VALLEY. MAY SEE
SOME DEBRIS CLOUDS DEVELOP TOWARD MORNING BUT WESTERLY FLOW ALOFT
WILL TEND TO KEEP THEM AT BAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
THERE WILL BE AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE REGION TUESDAY AND WEDNESDAY. STORM CHANCES BEGIN TO
RETREAT EASTWARD THURSDAY WITH ONLY SLIGHT CHANCES LEFT OVER
SOUTH-CENTRAL ARIZONA FRIDAY AND SATURDAY. ANTICIPATE MINIMUM
HUMIDITIES OF 25-30 PERCENT ON THE LOWER DESERTS TUESDAY AND
WEDNESDAY...TRENDING CLOSER TO 20 PERCENT BY SATURDAY. OVERNIGHT
HUMIDITIES WILL REMAIN GOOD...LESS SO OVER SOUTHEAST CALIFORNIA LATE
NEXT WEEK. TEMPERATURES WILL REMAIN ROUGHLY NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...WATERS
AVIATION....AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
335 PM PDT SAT AUG 9 2014
.UPDATE...AIR QUALITY ISSUES SECTION UPDATED.
&&
.SYNOPSIS...
TEMPERATURES WILL REMAIN A LITTLE ABOVE NORMAL OVER THE WEEKEND
THEN LOWER SLIGHTLY INTO EARLY NEXT WEEK. THUNDERSTORMS WILL BE
POSSIBLE OVER THE ENTIRE AREA BEGINNING EARLY MONDAY MORNING AND
CONTINUING INTO EARLY TUESDAY MORNING. AFTER TUESDAY MORNING
THUNDERSTORM CHANCES SHIFT TO THE SIERRA CREST.
&&
.DISCUSSION...INTERESTING WEATHER PATTERN DEVELOPING OVER THE AREA
THIS AFTERNOON...AS UPPER RIDGE CONTINUES TO STRENGTHEN OVER THE
FOUR CORNERS REGION AND AN UPPER LOW MOVES WEST SOUTHWEST TOWARD
THE SF BAY. THIS DOES LITTLE TO IMPACT THE REGION THIS
AFTERNOON...EXCEPT TO KEEP DAYTIME HIGH TEMPERATURES ABOVE NORMAL
AS THE UPPER HIGH BUILDS WEST. TEMPERATURES SO FAR THIS AFTERNOON
ROSE INTO THE 90S THROUGH THE VALLEY AND DESERT LOCATIONS...NEARLY
IDENTICAL TO THOSE OBSERVED YESTERDAY AT THIS TIME. CURRENT
TEMPERATURE FORECAST LOOKS RIGHT ON TRACK...WITH THE VALLEY
TOPPING OUT RIGHT AT OR SLIGHTLY ABOVE THE CENTURY MARK.
OTHERWISE...AFTERNOON AND EVENING THUNDERSTORMS WILL ONCE AGAIN BE
POSSIBLE OVER THE SIERRA NEVADA CREST...WITH A FEW RADAR ECHOS
ALREADY DEVELOPING OVER FRESNO COUNTY. THE NAM SHOWS THAT FRESNO
COUNTY MAY EXPERIENCE THE MOST NUMEROUS THUNDERSTORMS...AS MU CAPE
VALES PEAK IN THE 600 TO 800 J/KG RANGE. THE HRRR INDICATES THAT
THUNDERSTORM ACTION SHOULD SUBSIDE AROUND 02Z.
BY SUNDAY...THE UPPER LOW IS FORECAST TO MEANDER RIGHT AROUND THE
SF BAY...WITH MID LEVEL MOISTURE STREAMING NORTHWEST INTO SOUTHERN
CA AS THE UPPER HIGH CONTINUES TO DOMINATE FOUR CORNERS. SUNDAY
WILL SEE SLIGHTLY COOLER TEMPERATURES...WITH THE VALLEY EXPECTED
TO STAY BELOW 100 AND THE KERN CO DESERT JUST TOUCHING THE CENTURY
MARK.
THE BIG CHANGE IN THE WEATHER WILL COME LATE SUNDAY NIGHT INTO
MONDAY MORNING...AS MID LEVEL MOISTURE CONTINUES TO TREK
NORTHWESTWARD INTO KERN AND TULARE COUNTIES. AT THE SAME
TIME...MID LEVEL INSTABILITY INCREASES EARLY MONDAY MORNING FOR
THE SAME AREA. WHILE 500-700 MB MU CAPE VALUES PEAK IN THE 100-200
J/KG RANGE FOR THE VALLEY AND KERN CO...THOSE ARE SUFFICIENT
VALUES TO SEE AT LEAST A FEW STRIKES OF LIGHTNING BEGINNING AS
EARLY AS MONDAY MORNING.
MID LEVEL MOISTURE AND INSTABILITY ARE FORECAST TO CONTINUE NORTH
INTO FRESNO...MADERA...AND MARIPOSA COUNTIES THROUGH MONDAY AS
THE UPPER LOW REMAINS NEARLY STAGNANT. BY EARLY TUESDAY
MORNING...THE LOW IS FORECAST TO MOVE ONSHORE NEAR THE SF BAY AND
MOVE QUICKLY NORTH NORTHEAST INTO NORTHERN CALIFORNIA AND SOUTHERN
OREGON...SHIFTING ALL ACTIVITY EAST OUT OF THE AREA.
AGAIN...WE WANT TO REITERATE THAT THERE IS JUST A SLIGHT CHANCE
FOR THUNDERSTORMS OVER MUCH OF THE VALLEY EARLY MONDAY MORNING
INTO TUESDAY MORNING. GIVEN THE UNCERTAINTY OF THE POSITION OF THE
UPPER LOW AND EXACT TIMING OF THE LOW MOVEMENT...FORECASTER
CONFIDENCE IS LOW FOR SEEING ANY THUNDERSTORM ACTIVITY.
HOWEVER...WITH MID LEVEL CAPE VALUES BETWEEN 100 AND 300 J/KG
BLANKETING MUCH OF THE VALLEY...IT IS HARD TO IGNORE...THUS THE
SLIGHT CHANCE OF THUNDERSTORMS.
BY LATE TUESDAY MORNING...ALL THUNDERSTORM ACTIVITY WILL BE
CONFINED TO THE SIERRA CREST. AFTER TUESDAY EVENING...ALL MENTION
OF THUNDERSTORMS WAS REMOVED FROM THE FORECAST WITH THE UPPER FLOW
SHIFTING TO THE SOUTHWEST AND MID LEVEL MOISTURE MOVING WELL TO
THE EAST.
ON A SIDE NOTE...AFTER THIS AFTERNOON...VALLEY TEMPERATURES ARE
NOT FORECAST TO REACH THE 100 DEGREE MARK THROUGH AT LEAST NEXT
SATURDAY. IN FACT...BY TUESDAY DAYTIME HIGH TEMPERATURES WILL BE
BELOW NORMAL AND CONTINUE THIS WAY INTO AT LEAST FRIDAY.
&&
.AVIATION...
A CHANCE OF THUNDERSTORMS ALONG THE SIERRA CREST AFTER 18Z TODAY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HRS.
&&
.AIR QUALITY ISSUES...
ON SUNDAY AUGUST 10 2014... UNHEALTHY FOR SENSITIVE GROUPS IN KERN
COUNTY.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS LOW.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 08-09 111:1981 85:1907 78:1990 55:1916
KFAT 08-10 110:1898 83:1997 78:1981 53:1900
KFAT 08-11 113:1898 85:1999 78:2012 54:1919
KBFL 08-09 112:1981 82:1999 86:1978 51:1916
KBFL 08-10 109:1929 83:1997 86:1978 56:1907
KBFL 08-11 111:1940 82:1999 83:1978 54:1932
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...BSO
PREV DISCUSSION...RILEY
SYNOPSIS...RILEY
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
214 PM PDT SAT AUG 9 2014
.SYNOPSIS...
TEMPERATURES WILL REMAIN A LITTLE ABOVE NORMAL OVER THE WEEKEND
THEN LOWER SLIGHTLY INTO EARLY NEXT WEEK. THUNDERSTORMS WILL BE
POSSIBLE OVER THE ENTIRE AREA BEGINNING EARLY MONDAY MORNING AND
CONTINUING INTO EARLY TUESDAY MORNING. AFTER TUESDAY MORNING
THUNDERSTORM CHANCES SHIFT TO THE SIERRA CREST.
&&
.DISCUSSION...INTERESTING WEATHER PATTERN DEVELOPING OVER THE AREA
THIS AFTERNOON...AS UPPER RIDGE CONTINUES TO STRENGTHEN OVER THE
FOUR CORNERS REGION AND AN UPPER LOW MOVES WEST SOUTHWEST TOWARD
THE SF BAY. THIS DOES LITTLE TO IMPACT THE REGION THIS
AFTERNOON...EXCEPT TO KEEP DAYTIME HIGH TEMPERATURES ABOVE NORMAL
AS THE UPPER HIGH BUILDS WEST. TEMPERATURES SO FAR THIS AFTERNOON
ROSE INTO THE 90S THROUGH THE VALLEY AND DESERT LOCATIONS...NEARLY
IDENTICAL TO THOSE OBSERVED YESTERDAY AT THIS TIME. CURRENT
TEMPERATURE FORECAST LOOKS RIGHT ON TRACK...WITH THE VALLEY
TOPPING OUT RIGHT AT OR SLIGHTLY ABOVE THE CENTURY MARK.
OTHERWISE...AFTERNOON AND EVENING THUNDERSTORMS WILL ONCE AGAIN BE
POSSIBLE OVER THE SIERRA NEVADA CREST...WITH A FEW RADAR ECHOS
ALREADY DEVELOPING OVER FRESNO COUNTY. THE NAM SHOWS THAT FRESNO
COUNTY MAY EXPERIENCE THE MOST NUMEROUS THUNDERSTORMS...AS MU CAPE
VALES PEAK IN THE 600 TO 800 J/KG RANGE. THE HRRR INDICATES THAT
THUNDERSTORM ACTION SHOULD SUBSIDE AROUND 02Z.
BY SUNDAY...THE UPPER LOW IS FORECAST TO MEANDER RIGHT AROUND THE
SF BAY...WITH MID LEVEL MOISTURE STREAMING NORTHWEST INTO SOUTHERN
CA AS THE UPPER HIGH CONTINUES TO DOMINATE FOUR CORNERS. SUNDAY
WILL SEE SLIGHTLY COOLER TEMPERATURES...WITH THE VALLEY EXPECTED
TO STAY BELOW 100 AND THE KERN CO DESERT JUST TOUCHING THE CENTURY
MARK.
THE BIG CHANGE IN THE WEATHER WILL COME LATE SUNDAY NIGHT INTO
MONDAY MORNING...AS MID LEVEL MOISTURE CONTINUES TO TREK
NORTHWESTWARD INTO KERN AND TULARE COUNTIES. AT THE SAME
TIME...MID LEVEL INSTABILITY INCREASES EARLY MONDAY MORNING FOR
THE SAME AREA. WHILE 500-700 MB MU CAPE VALUES PEAK IN THE 100-200
J/KG RANGE FOR THE VALLEY AND KERN CO...THOSE ARE SUFFICIENT
VALUES TO SEE AT LEAST A FEW STRIKES OF LIGHTNING BEGINNING AS
EARLY AS MONDAY MORNING.
MID LEVEL MOISTURE AND INSTABILITY ARE FORECAST TO CONTINUE NORTH
INTO FRESNO...MADERA...AND MARIPOSA COUNTIES THROUGH MONDAY AS
THE UPPER LOW REMAINS NEARLY STAGNANT. BY EARLY TUESDAY
MORNING...THE LOW IS FORECAST TO MOVE ONSHORE NEAR THE SF BAY AND
MOVE QUICKLY NORTH NORTHEAST INTO NORTHERN CALIFORNIA AND SOUTHERN
OREGON...SHIFTING ALL ACTIVITY EAST OUT OF THE AREA.
AGAIN...WE WANT TO REITERATE THAT THERE IS JUST A SLIGHT CHANCE
FOR THUNDERSTORMS OVER MUCH OF THE VALLEY EARLY MONDAY MORNING
INTO TUESDAY MORNING. GIVEN THE UNCERTAINTY OF THE POSITION OF THE
UPPER LOW AND EXACT TIMING OF THE LOW MOVEMENT...FORECASTER
CONFIDENCE IS LOW FOR SEEING ANY THUNDERSTORM ACTIVITY.
HOWEVER...WITH MID LEVEL CAPE VALUES BETWEEN 100 AND 300 J/KG
BLANKETING MUCH OF THE VALLEY...IT IS HARD TO IGNORE...THUS THE
SLIGHT CHANCE OF THUNDERSTORMS.
BY LATE TUESDAY MORNING...ALL THUNDERSTORM ACTIVITY WILL BE
CONFINED TO THE SIERRA CREST. AFTER TUESDAY EVENING...ALL MENTION
OF THUNDERSTORMS WAS REMOVED FROM THE FORECAST WITH THE UPPER FLOW
SHIFTING TO THE SOUTHWEST AND MID LEVEL MOISTURE MOVING WELL TO
THE EAST.
ON A SIDE NOTE...AFTER THIS AFTERNOON...VALLEY TEMPERATURES ARE
NOT FORECAST TO REACH THE 100 DEGREE MARK THROUGH AT LEAST NEXT
SATURDAY. IN FACT...BY TUESDAY DAYTIME HIGH TEMPERATURES WILL BE
BELOW NORMAL AND CONTINUE THIS WAY INTO AT LEAST FRIDAY.
&&
.AVIATION...
A CHANCE OF THUNDERSTORMS ALONG THE SIERRA CREST AFTER 18Z TODAY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HRS.
&&
.AIR QUALITY ISSUES...
ON SATURDAY AUGUST 9 2014... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN AND MADERA COUNTIES AND SEQUOIA NATIONAL PARK AND
FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS LOW.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 08-09 111:1981 85:1907 78:1990 55:1916
KFAT 08-10 110:1898 83:1997 78:1981 53:1900
KFAT 08-11 113:1898 85:1999 78:2012 54:1919
KBFL 08-09 112:1981 82:1999 86:1978 51:1916
KBFL 08-10 109:1929 83:1997 86:1978 56:1907
KBFL 08-11 111:1940 82:1999 83:1978 54:1932
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...BSO
SYNOPSIS...RILEY
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
345 PM EDT SAT AUG 9 2014
.SYNOPSIS...
THE REGION WILL SEE ONE MORE DAY OF TRANQUIL WEATHER AS THE HIGH
SLOWLY STARTS TO MOVE OFF SHORE TOMORROW NIGHT. THEN, AN AREA OF LOW
PRESSURE IN THE OHIO VALLEY WILL MOVE NORTHEASTWARD INTO
SOUTHEASTERN CANADA AND BRING A COLD FRONT ACROSS THE AREA TUESDAY
NIGHT INTO EARLY WEDNESDAY. HIGH PRESSURE WILL BUILD BACK IN BEHIND
THE DEPARTING FRONT FOR THE LATTER PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A STATIONARY FRONTAL BOUNDARY IS LOCATED WELL SOUTH OF THE
REGION THIS AFTERNOON WITH HIGH PRESSURE IN CONTROL. THE MAIN
IMPACT HAS BEEN FOR PERIODIC INCREASE IN THE CLOUDS ACROSS THE
SOUTHEAST PORTION OF THE CWA WITH ANY SHOWERS WELL TO OUR SOUTHEAST.
DEWPOINTS WERE ADJUSTED IN THE SHORT TERM TO MATCH CURRENT OBS,
LIKELY SOME MIXING ACCOUNTING FOR THE SLIGHTLY LOWER DEWPOINTS. BOTH
THE HRRR AND RAP CONTINUE THIS TREND TONIGHT. WINDS WILL LIKELY
BECOME LIGHT AND VARIABLE TONIGHT MAKING FOR GOOD RADIATIONAL COOLING
CONDITIONS. THERE IS A LOW CHANCE OF PATCHY FOG FORMATION IN SOME
VALLEYS. PATCHY FOG WAS LEFT OUT OF THE GIRDS GIVEN THE WEAK SIGNAL
FROM THE LAMP AND NAM MOS GUIDANCE SETS ALONG WITH BROAD DEWPOINT
DEPRESSIONS SHOWING UP ON BUFKIT SOUNDINGS. STAYED CLOSE TO MET/MAV
GUIDANCE ON THE LOWS BUT ALSO TAKING INTO ACCOUNT LOCAL MESOSCALE
EFFECTS OF RADIATIONAL COOLING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE STATIONARY FRONTAL BOUNDARY CONTINUES TO BE WELL SOUTH OF
OUR REGION WITH HIGH PRESSURE LOCATED JUST OFFSHORE. CONTINUED DRY
FORECAST. STEEP LAPSE RATES MAY ONCE AGAIN CONTRIBUTE TO THE
DEVELOPMENT OF SCATTERED CUMULUS IN THE AFTERNOON. WINDS ARE LIKELY
TO SHIFT TO THE SOUTHEAST IN THE MORNING THEN THE SOUTH OR SOUTHWEST
IN THE AFTERNOON. MODELED 925 MB TEMPS INDICATE THAT IT MIGHT BE
HARD TO REACH THE HIGH TEMPERATURES ADVERTISED BY THE MET AND MAV
GUIDANCE SETS SO THE FORECAST UNDERCUTS THESE GUIDANCE SETS BY A COUPLE
OF DEGREES. DEWPOINT TEMPERATURES ARE ALSO FORECASTED LOWER THAN
MET/MAV IN THE AFTERNOON GIVEN THE POTENTIAL FOR MIXING. ANOTHER
NICE SUMMER DAY OVERALL!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BY MONDAY, THE SURFACE HIGH HAS SHIFTED OFF SHORE, WHILE THE UPPER
LEVEL SHORT WAVE RIDGE PROPAGATES OVER THE REGION. WITH THE
INCREASED THICKNESSES, AND SOUTHERLY FLOW, TEMPERATURES ON MONDAY
SHOULD BE NEAR OR JUST ABOVE NORMAL. WITH THE INCREASED SOUTHERLY
COMPONENT IN THE FLOW, ESPECIALLY TOWARDS THE END OF THE DAY,
COULD SEE SOME OF THE SHOWER AND THUNDERSTORM ACTIVITY SOUTHWEST
OF OUR REGION MOVE INTO DELMARVA AND SPREAD NORTH.
TUESDAY THROUGH WEDNESDAY...THIS IS THE PERIOD OF GREATEST INTEREST
AS THE UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT MOVE
THROUGH THE REGION. IN ADVANCE OF THIS TROUGH, THERE IS A THREAT FOR
HEAVY RAIN. THE QUESTION IS THOUGH THE TIMING OF THE TROUGH, AND
CONSEQUENTLY, THE HIGHEST RISK OF HEAVY RAIN. THE LATEST GFS AND
ECMWF ARE MUCH MORE PROGRESSIVE THAN THE CMC, NAM OR PREVIOUS RUN
OF THE ECMWF, BRINGING THE COLD FRONT THROUGH MUCH OF THE REGION BY
LATE TUESDAY NIGHT. FOR NOW THE FORECAST FAVORS THE LATEST ECMWF
AND GFS, AS THIS WOULD BE AN UNUSUAL SET UP FOR A BLOCKING
PATTERN, AND THE MORE PROGRESSIVE PATTERN IS MUCH MORE CONSISTENT
WITH THE BEHAVIOR OF RECENT TROUGHS. INSTABILITY WILL BE LIMITED
AS THE ON SHORE FLOW SHOULD DEVELOP WELL AHEAD OF ANY WIDESPREAD
PRECIPITATION, LEADING TO A COOL, STABLE, BOUNDARY LAYER. HOWEVER,
DEPENDING ON HOW FAR SOUTH THE TROUGH DIGS, BULK SHEAR VALUES
COULD BE 30 TO 40 KT. AT THIS POINT THOUGH, ANY SEVERE THREAT IS
VERY MINIMAL GIVEN ML CAPE VALUES GENERALLY BELOW 500 J/KG.
PRECIPITABLE WATER VALUES WILL BE WELL ABOVE NORMAL, ABOVE 2
INCHES POSSIBLY IN SOUTHERN NJ. HOWEVER, AGAIN DEPENDING ON HOW
FAR SOUTH THE TROUGH DIGS, STORM MOTIONS WILL LIKELY BE QUITE
FAST (GENERALLY ABOVE 20KT). THE COLD FRONT SHOULD ARRIVE EITHER
LATE TUESDAY NIGHT OR EARLY WEDNESDAY, USHERING IN MUCH DRIER AIR
AND AN ABRUPT SHIFT TO WESTERLY WINDS.
THURSDAY THROUGH SATURDAY...THE UPPER LEVEL TROUGH SHOULD LIFT NE
THROUGH THIS PERIOD, AND IN ITS WAKE, EXPECT NORTHWESTERLY FLOW
RESULTING IN TEMPERATURES WELL BELOW NORMAL. WITH THE DRIER AIR
AND A SURFACE HIGH IN PLACE, SHOULD NOT SEE ANY PRECIPITATION
THROUGH THESE PERIODS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
ANOTHER GREAT WEATHER FLYING DAY IS IN PROGRESS AROUND THE
REGION. VFR CONDITIONS EXPECTED THIS AFTERNOON AND TONIGHT. WINDS
WILL BE LIGHT WITH THE HIGH PRESSURE AREA NEARBY. WIND DIRECTIONS
WILL CONTINUE TO BE VARIABLE THROUGHOUT THE REMAINDER OF THE AFTERNOON
AND TONIGHT. HOWEVER, THERE WILL PROBABLY BE SOME SEA- BREEZE
ACTIVITY FOR KACY AND KMIV SHIFTING THE WIND TO SE FOR A TIME. AS OF
19Z THE SEA BREEZE HAS REACHED ACY.
TOMORROW WILL BE ANOTHER VFR DAY ACROSS THE REGION. SOME PATCHY
CUMULUS MAY DEVELOP IN THE AFTERNOON AROUND 5,000 FEET. WINDS MAY
START OFF VARIABLE BEFORE TURING TO THE SOUTHEAST THEN THE
SOUTH/SOUTHWEST AS THE DAY GOES ON. SOME EARLY MORNING (7-11Z)
PATCHY FOG OR VISIBILITY RESTRICTION CAN`T BE RULED OUT AT RDG,
MIV OR ACY. HOWEVER, CONFIDENCE IN IT OCCURRING IS LOW AND THE 18Z
TAFS REFLECT THAT.
OUTLOOK...
MONDAY...BEGINNING WITH VFR CONDITIONS. BY MID DAY, LOW LEVEL
STRATUS LEADING TO MVFR CEILINGS WILL BE POSSIBLE ALONG THE SHORE
BEFORE IT SPREADS WEST. THERE IS ALSO A SMALL RISK ISOLATED TSRA
COULD APPROACH KILG AND KRDG LATE IN THE DAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...EXPECT A CONSISTENT MVFR CEILING,
POSSIBLY LOWERING TO IFR AT TIMES THROUGH THE PERIOD. ALSO, EXPECT
TO SEE WIDESPREAD SHRA AND TSRA ESPECIALLY TUESDAY AFTERNOON AND
NIGHT. IFR VISIBILITIES WILL BE POSSIBLE WITH ANY SHRA AND TSRA.
EXPECT SOUTHEASTERLY WINDS, BREEZY AT TIMES.
WEDNESDAY...CONDITIONS GRADUALLY IMPROVING TO VFR. A FEW LINGERING
SHRA AND TSRA POSSIBLE. EXPECT AN ABRUPT SHIFT TO WESTERLY WINDS EARLY
IN THE DAY.
THURSDAY...GENERALLY VFR CONDITIONS. COULD HAVE BREEZY WESTERLY
AND NORTHWESTERLY WINDS FOR MUCH OF THE DAY TIME HOURS.
&&
.MARINE...
SEAS AND WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA ATTM. SEAS
HAVE BEEN AROUND TWO FEET ON THE OCEAN AND LIKELY WILL REMAIN AROUND
TWO FEET THROUGH TOMORROW. THINK WAVEWATCH MAY BE SLIGHTLY TO LOW
BUT STILL TWO FEET SEEMS REASONABLE. WINDS WILL EB VARIABLE THROUGH
TONIGHT AND MORE OUT OF THE SOUTH TOMORROW LESS THAN 10 KNOTS.
OUTLOOK...
MONDAY...WINDS AND SEAS BELOW SCA CONDITIONS EXPECTED. THERE IS A
SMALL RISK FOR FOG TO DEVELOP ESPECIALLY NEAR SHORE.
TUESDAY...SMALL CRAFT ADVISORY CONDITIONS LIKELY. WIND GUSTS
FREQUENTLY NEAR OR ABOVE 25 KT EXPECTED. IN ADDITION, WAVE HEIGHTS
SHOULD BUILD TO 6 TO 7 FT.
WEDNESDAY AND THURSDAY....WAVE HEIGHTS MAY BE SLOW TO FALL BELOW
5FT EARLY ON WEDNESDAY, BUT OTHERWISE CONDITIONS ARE EXPECTED TO
BE BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.TIDES/COASTAL FLOODING...
PROJECTED TIDAL DEPARTURES FOR THIS EVENING`S HIGH TIDE SHOULD FALL
SHORT OF MINOR TIDAL FLOODING THRESHOLDS. THE BETTER CHANCES FOR
MINOR FLOOD THRESHOLDS CONTINUE TO BE WITH THE SUNDAY THROUGH
TUESDAY EVENING HIGH TIDE CYCLES. WITH HIGHER ASTRONOMICAL TIDAL
LEVELS COMBINED WITH A STRONGER AND MORE PERSISTENT ONSHORE FLOW,
ALLOWING FOR A GREATER POSITIVE DEPARTURE, MINOR COASTAL FLOODING
BECOMES MORE POSSIBLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JOHNSON
NEAR TERM...GAINES
SHORT TERM...GAINES
LONG TERM...JOHNSON
AVIATION...GAINES/JOHNSON
MARINE...GAINES/JOHNSON
TIDES/COASTAL FLOODING...HEAVENER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
400 PM EDT SAT AUG 9 2014
.DISCUSSION...
CURRENT/TONIGHT...
DIURNAL CONVECTION GOT A SLIGHTLY EARLIER START THAN ON FRIDAY. BY
MID AFTN NMRS SHRAS/SCT TSRAS WERE PUSHING ACRS THE FL TURNPIKE WITH
WELL DEFINED OUTFLOW BDRYS RACING AHEAD OF THE CONVECTION TOWARD
THE COASTAL COUNTIES. EAST COAST SEA BREEZE WAS LARGELY PINNED NEAR
ALONG THE BARRIER ISLANDS AS ONLY A FEW CSTL SITES HAD REPORTED A
WNDSHFT FM SW TO SE.
COLLISION BTWN THE OUTFLOW BDRYS AND THE EAST COAST SEA BREEZE WILL
OCCUR WELL BEFORE SUNSET AND SHOULD BURN OFF MOST OF THE AVAILABLE
ENERGY BY MID EVNG. LATEST OBS INDICATE LITTLE CHANGE IN THE OVERALL
WX PATTERN WITH SHALLOW MID LVL LAPSE RATES BTWN 5.5-6.5C/KM...
STEEPEST ALONG THE TREASURE COAST WHERE SOME DRIER MID LVL AIR HAS
WORKED ITS WAY UP FROM S FL. RUC ANALYSIS SHOWS A WEAK MID LVL VORT
AXIS HAS SET UP ALONG THE W FL COAST THAT IS EMBEDDED WITHIN 5-10KTS
OF S/SW FLOW. WHILE THIS IS PRODUCING SOME PVA ACRS E CENT FL...ITS
MAGNITUDE IS QUITE LOW AND WILL DO LITTLE TO ENHANCE OVERALL STORM
STRENGTH.
WILL GO WITH A PRE 1ST PD TO COVER ONGOING PRECIP...ENDING PRECIP BY
02Z. LIGHT WINDS AND CLEARING SKIES AFT MIDNIGHT WILL ALLOW MIN
TEMPS TO DROP TO WITHIN A FEW DEGS OF SFC DEWPOINTS...CURRENTLY IN
THE M/U70S.
UPCOMING WEEK...(PREV DISC)
SYNOPTIC PATTERN THAT SETS UP FOR MOST OF NEXT WEEK WILL SEE THE
DEEP LAYER ATLANTIC RIDGE SUPPRESSED BACK ACROSS SOUTH
FLORIDA/FLORIDA STRAITS AS THE BROAD EAST COAST TROUGH BECOMES
RE-ESTABLISHED. THIS PATTERN HAS BECOME THE DEFAULT SO FAR THIS
SUMMER.
WEAK LOW PRESSURE THAT DEVELOPS EARLY IN THE WEEK BRINGS A FRONTAL
BOUNDARY INTO NORTH FLORIDA WHERE IT HANGS UP FOR THE REMAINDER OF
THE WEEK AGAINST THE STOUT ATLANTIC RIDGE AXIS. PREVAILING
SOUTH-SOUTHWEST FLOW WILL LIKELY HANG UP THE EAST COAST SEA BREEZE
ALONG THE COAST MOST AFTERNOONS IF IT IS ABLE TO DEVELOP AT
ALL...AND THEN LIKELY ONLY SOUTH OF CAPE CANAVERAL.
BOTH GFS AND ECMWF ARE A LITTLE MORE ENTHUSIASTIC ABOUT KEEPING THE
FRONTAL MOISTURE FURTHER NORTH AND INSTEAD BRINGING THE DRY AIR
POCKET CURRENTLY OVER THE SOUTHERN BAHAMAS AROUND THE RIDGE INTO THE
PENINSULA. SO DESPITE WHAT OTHERWISE WOULD BE FAVORABLE FLOW...HAVE
KEPT POPS AROUND CLIMO AT 30-40 PERCENT AS THIS WOULD KEEP SOME
CONVECTION SUPPRESSED. HOWEVER IT WILL BE THE SMALL DAY TO DAY
FLUCTUATIONS IN THE RIDGE AXIS/STRENGTH OF THE OFFSHORE FLOW/LOW-MID
LEVEL MOISTURE THAT WILL ULTIMATELY DETERMINE THE STORM COVERAGE AND
THESE ARE HARD TO PIN DOWN IN THE LONG TERM.
&&
.AVIATION...
THRU 10/00Z...SFC WNDS E/SE 5-10KTS CSTL SITES...S/SW INTERIOR
SITES...SCT MVFR SHRAS/IFR TSRAS WITH OCNL SFC WND G25-30KTS...MVG
NE ARND 10KTS. BTWN 10/00Z-10/02Z...SFC WNDS BCMG S ARND 5KTS...SCT
MVFR SHRAS/ISOLD IFR TSRAS. AFT 10/02Z...VFR ALL SITES...S/SW SFC
WNDS BLO 5KTS.
&&
.MARINE...
TONIGHT...EAST COAST SEA BREEZE WILL COLLAPSE WITHIN AN HR OR TWO OF
SUNSET WITH WINDS SHIFTING BACK TO THE S/SW AOB 10KTS...SEAS AOB
2FT NEARSHORE AND 2-3FT OFFSHORE...DOMINANT PDS ARND 9SEC. OFFSHORE
MVG TSTMS THRU EARLY EVNG.
SUN-THU...PERSISTENT TROFFING PATTERN OVER THE NE CONUS WILL COMBINE
WITH A FRONTAL BOUNDARY DROPPING INTO N FL TO KEEP THE ATLC RIDGE
AXIS SUPPRESSED NEAR OR SOUTH OF LAKE OKEECHOBEE AND THE NRN BAHAMAS
FOR MUCH OF THE UPCOMING WEEK. A GENTLE TO MODERATE S/SW BREEZE WILL
PREVAIL ACRS THE LCL ATLC WITH SEAS AOB 2FT NEARSHORE AND 2-3FT
OFFSHORE. GRADIENT SHOULD BE STRONG ENOUGH TO PREVENT THE EAST COAST
SEA BREEZE FROM FORMING...OR AT LEAST LIMITING IT TO A FEW HRS OF
AFTN S/SE FLOW ALONG THE TREASURE COAST EACH AFTN. OFFSHORE MVG
AFTN/EVNG TSTMS WILL REMAIN THE PRIMARY BOATING THREAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 93 76 93 / 30 40 30 30
MCO 75 95 75 96 / 20 30 20 30
MLB 76 91 75 92 / 30 40 30 20
VRB 75 92 74 91 / 30 40 30 20
LEE 76 95 76 95 / 20 30 20 30
SFB 76 96 77 96 / 20 30 20 30
ORL 76 95 76 95 / 20 30 20 30
FPR 74 92 74 92 / 20 40 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
RADAR/IMPACT WX.......SHARP/LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
350 PM EDT SAT AUG 9 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN UNAMPLIFIED UPPER LEVEL
PATTERN ACROSS THE CONUS...WITH THE EXCEPTION OF THE LONGWAVE TROUGH
QUICKLY DEPARTING THE NORTHEASTERN STATES INTO THE CANADIAN
MARITIMES. NORTHERN STREAM FLOW IS LOCATED AT RATHER HIGH LATITUDES
TO THE NORTH OF THE CANADIAN BORDER...WHILE AT THE SAME TIME THE
SOUTHERN STREAM IS ALSO DISPLACED FAIRLY FAR TO THE NORTH ALIGNED
FROM THE SOUTHWESTERN STATES TO THE TN/OH VALLEY AND THEN OFF THE
MID-ATLANTIC COAST. CLOSER TO HOME WE FIND A BROAD BUT WEAK EXPANSE
OF MID/UPPER LEVEL RIDGING EXTENDING FROM THE GULF OF
MEXICO...ACROSS THE FL PENINSULA. WV IMAGERY AND HIGH LEVEL
400-250MB ANALYSIS SUGGEST A SUBTLE UPPER LOW FEATURE IMPINGING ON
THE RIDGE OVER THE BAHAMAS...HOWEVER NWP GUIDANCE KEEPS THIS
ENERGY/VORTICITY FROM HAVING MUCH IMPACT ON OUR LOCAL WEATHER THIS
WEEKEND AS IT STAYS ON A QUICK WESTWARD PATH OVER CUBA/FL STRAITS
AND THEN OFF INTO THE SOUTH-CENTRAL GULF OF MEXICO DURING EARLY NEXT
WEEK.
REGIONAL RADARS SHOW THE ACTIVE CONVECTIVE PATTERN THAT WAS OVER THE
COASTAL WATERS THIS MORNING HAS TRANSITIONS EASTWARD WITH SEA-BREEZE
DEVELOPMENT/DIURNAL HEATING...AND IS NOW MAINLY EAST OF THE I-75
CORRIDOR ACROSS THE INTERIOR PENINSULA. PORTIONS OF NORTHERN
HIGHLANDS AND POLK COUNTY LOOK TO GET QUITE WET THROUGH THE NEXT
COUPLE OF HOURS BASED ON LATEST RADAR TRENDS. THE BEACHES ARE NOW
FOR THE MOST PART DRY WITHIN THE DIVERGENCE AND SUBSIDENCE DOMINATED
FLOW BEHIND THE SEA-BREEZE. OUTSIDE OF A SLIGHT CHANCE OF AN
ISOLATED SHOWER COMING BACK TOWARD THE COAST WITH ANY OUTFLOW
BOUNDARIES THIS EVENING...THE BEACHES SHOULD REMAIN MOSTLY DRY FOR
THE REST OF THE DAY.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
TONIGHT...
EVENING STORMS FADE WITH SUNSET...SETTING UP A MOSTLY DRY
PERIOD OVER THE INTERIOR. SUBTROPICAL RIDGE AXIS SHIFTS JUST A TAD
FURTHER NORTH. GFS/NAM/SREF ALL SHOWING AN AXIS OF SURFACE
CONVERGENCE DEVELOPING FROM THE NATURE COAST SOUTHWEST TO THE WATERS
WEST OF TAMPA BAY. THIS BAND OF CONVERGENCE SHOULD IT MATERIALIZE
WOULD BE ENOUGH TO GET AN ACTIVE AREA OF SHALLOW CONVECTION GOING
OVER THE NORTHERN HALF OF THE FORECAST COASTAL WATERS...AND THE FLOW
WOULD TEND TO BRING THIS ACTIVITY TOWARD THE COAST LATE TONIGHT.
THEREFORE WILL FAVOR PINELLAS/COASTAL SARASOTA COUNTIES NORTHWARD
FOR PRE-DAWN/EARLY SUNDAY MORNING SCT STORMS MIGRATING TO THE COAST
IN THE POP GRIDS. CURRENTLY SHOWING 30-40% POPS FOR THIS FAVORED
AREA AFTER 09-12Z. LATEST 12Z GUIDANCE SUITE CERTAINLY CONTINUED TO
SHOW THIS CONVERGENCE ZONE...HOWEVER SUBTLE DIFFERENCES IN JUST
WHERE EACH MEMBER HAS THE BEST FOCUS FOR LIFT MAKE IT DIFFICULT TO
REALLY CLOSE IN ON A SPECIFIC AREA FOR HIGHER POPS. WILL KEEP THE
CHANCE POPS FOR NOW...AND LET THE OVERNIGHT SHIFT INCREASE/DECREASE
THINGS BASED ON SURFACE ANALYSIS/RADAR TRENDS AFTER MIDNIGHT.
OTHERWISE...LOOKING FOR A WARM AND HUMID AUGUST NIGHT WITH LOWS IN
THE LOWER/MID 70S INLAND AND UPPER 70S TO NEAR 80 AT THE BEACHES.
SUNDAY...
THE MORNING HOURS WILL CONTINUE THE ONSHORE MIGRATING SHOWER THREAT
FROM THE TAMPA BAY AREA NORTHWARD FOR AT LEAST A FEW DAYLIGHT HOURS.
ONCE THE TERRESTRIAL HEATING REACHES A POINT THAT WE BEGIN TO
DEVELOP LOCAL SEA-BREEZES...THE RESULTING DISRUPTION OF FLOW SHOULD
WEAKEN ANY CONVERGENCE BAND OVER THE COASTAL WATERS AND QUICKLY
DECREASE THE COVERAGE OF COASTAL STORMS INTO THE EARLY AFTERNOON.
SIMILAR TO WHAT IS OCCURRING TODAY...THE INLAND MOVEMENT OF THE
SEA-BREEZE SHOULD FOCUS THE BEST CONVECTIVE DEVELOPMENT BY THE
MIDDLE AFTERNOON/EARLY EVENING HOURS ALONG AND LIKELY FURTHER EAST
FROM THE I-75 CORRIDOR. GFS/ECMWF BOTH SHOW SOME INTRUSION OF DRIER
AIR MOVING INTO THE SOUTHERN PENINSULA BY SUNDAY AFTERNOON...BUT AS
IT LOOKS NOW...ANY SIGNIFICANT IMPACTS TO CONVECTIVE FAVORABILITY
WILL REMAIN TO THE SOUTH OF OUR FORECAST AREA FOR SUNDAY. BETTER
CHANCES FOR THE DRIER AIR ALOFT TO DECREASE OUR DIURNAL RAIN CHANCES
AS WE HEAD INTO THE EARLY PORTION OF THE UPCOMING WORK WEEK.
EXPECT TEMPERATURES TO CLIMB INTO THE LOWER 90S INLAND AND UPPER 80S
TO AROUND 90 AT THE BEACHES SUNDAY AFTERNOON. ENJOY THE REST OF YOUR
WEEKEND!
&&
.LONG TERM (SUNDAY NIGHT-SATURDAY)...
QUITE A STAGNANT PATTERN IS EXPECTED ACROSS WEST-CENTRAL AND
SOUTHWEST FLORIDA THROUGH THE LONG TERM PERIOD. THE HIGH PRESSURE
RIDGE AXIS WILL REMAIN ACROSS SOUTH FLORIDA AND THE FLORIDA
STRAIGHTS THROUGH THE PERIOD...KEEPING A GENERAL WEST-SOUTHWESTERLY
BOUNDARY LAYER FLOW IN PLACE ACROSS THE FORECAST AREA. AS A
RESULT...EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EACH
DAY WITH ACTIVITY STARTING ALONG THE COAST DURING THE MORNING INTO
THE EARLY AFTERNOON HOURS BEFORE TRANSITIONING INTO INTERIOR
LOCATIONS DURING THE AFTERNOON INTO THE EVENING HOURS. TEMPERATURES
THROUGH THE PERIOD ARE EXPECTED TO REMAIN NEAR TO SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION...
MOST NUMEROUS STORM COVERAGE HAS NOW PUSHED INLAND FROM MOST OF THE
TERMINALS. BEST CHANCE TO STILL SEE A BRIEF VIS/CIG RESTRICTION WITH
A THUNDERSTORM THROUGH LATE AFTERNOON WILL BE KLAL. OTHERWISE VFR
CONDITIONS SHOULD PREVAIL WITH JUST A SLIGHT CHANCE OF A BRIEF
SHOWER AT THE REST OF THE TERMINALS. VFR CONDITIONS SHOULD PREVAIL
FOR MUCH OF THE OVERNIGHT AS WELL. LATE AT NIGHT APPROACHING
DAWN...CHANCES FOR SHOWERS MIGRATING OFF THE GULF OF MEXICO TOWARD
KPIE...KTPA...AND KSRQ WILL INCREASE AND CONTINUE INTO SUNDAY
MORNING. HAVE ADDED VCSH/VCTS AFTER 09-12Z FOR THESE TERMINALS.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL BE ALIGNED ACROSS SOUTH-CENTRAL
FLORIDA THROUGH THE EARLY PORTION OF THE WEEK KEEPING WINDS AND SEAS
LOW. SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE OVERNIGHT AND
EARLY MORNING HOURS OVER THE GULF AND COASTAL REGIONS...ESPECIALLY
FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST. THIS ACTIVITY WILL
BE MOST NUMEROUS IN THE MORNING HOURS AND THEN PUSH INLAND FOR EACH
AFTERNOON.
&&
.FIRE WEATHER...
NO SIGNIFICANT DEVIATION FROM AUGUST CLIMATOLOGY IS EXPECTED THE
NEXT SEVERAL DAYS AS HIGH PRESSURE REMAINS ANCHORED ACROSS THE
STATE. BEST CHANCES FOR EARLY MORNING SHOWERS WILL BE NEAR THE
COAST...WITH MORE NUMEROUS SHOWERS AND STORMS DEVELOPING INLAND
DURING THE AFTERNOON AND EARLY EVENING HOURS. RELATIVE HUMIDITY
VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS...HOWEVER DISPERSION
INDICES WILL FLIRT WITH 75 SUNDAY ALONG AND TO THE NORTH OF THE I-4
CORRIDOR.
FOG POTENTIAL...ISOLATED POCKETS OF SHALLOW PATCHY GROUND FOG
WILL BE POSSIBLE IN OPEN FIELDS EACH MORNING...BUT SIGNIFICANT
VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 92 79 90 / 20 30 10 20
FMY 75 93 77 93 / 20 40 10 40
GIF 76 94 76 92 / 40 50 20 40
SRQ 81 90 78 91 / 20 30 10 20
BKV 71 93 73 91 / 20 40 20 40
SPG 80 91 81 90 / 30 40 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
850 AM EDT SAT AUG 9 2014
.UPDATE (TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN ACROSS THE CONUS...WITH THE EXCEPTION OF THE LONGWAVE
TROUGH DEPARTING THE NORTHEASTERN STATES INTO THE CANADIAN
MARITIMES. NORTHERN STREAM FLOW IS LOCATED AT RATHER HIGH LATITUDES
TO THE NORTH OF THE CANADIAN BORDER...WHILE AT THE SAME TIME THE
SOUTHERN STREAM IS ALSO DISPLACED FAIRLY FAR TO THE NORTH ALIGNED
FROM THE SOUTHWESTERN STATES TO THE TN/OH VALLEY AND THEN OFF THE
MID-ATLANTIC COAST. CLOSER TO HOME WE FIND A BROAD BUT WEAK EXPANSE
OF MID/UPPER LEVEL RIDGING EXTENDING FROM THE GULF OF
MEXICO...ACROSS THE FL PENINSULA. WV IMAGERY AND HIGH LEVEL
400-250MB ANALYSIS SUGGEST A SUBTLE UPPER LOW FEATURE IMPINGING ON
THE RIDGE OVER THE BAHAMAS...HOWEVER NWP GUIDANCE KEEPS THIS
ENERGY/VORTICITY FROM HAVING MUCH IMPACT ON OUR LOCAL WEATHER AS IT
STAYS ON A QUICK WESTWARD PATH OVER CUBA/FL STRAITS AND THEN OFF
INTO THE SOUTH-CENTRAL GULF OF MEXICO DURING EARLY NEXT WEEK.
TAKING A FIRST GLANCE AT THE 09/12Z KTBW SOUNDING PROFILE WE SEE NO
FEATURES OF MUCH SIGNIFICANCE. PW VALUES ARE A BIT ABOVE
NORMAL...BUT CERTAINLY NOT ANYTHING UNUSUAL FOR THE LATER SUMMER
PERIOD. MID-LEVEL TEMPS ARE NEAR AVERAGE AND LAPSE RATES THROUGH
MUCH OF THE COLUMN ARE ON THE POOR SIDE. THE PROFILE IS CERTAINLY
NOT HOSTILE TOWARD DEEP CONVECTION...BUT NOT ONE THAT WOULD SUPPORT
MUCH IN THE WAY OF STRONG STORM EITHER. "RUN OF THE MILL" SUMMER
STORMS SHOULD BE THE NORM TODAY...WITH ONLY ISOLATED STRONGER
UPDRAFTS. LOCAL AND NATIONAL CONVECTION ALLOWING MODELS ALL AGREE
WITH THIS ASSESSMENT IN THEIR SIMULATIONS...MAXING OUT CONVECTIVE
UPDRAFT STRENGTHS BETWEEN 10-14 M/S.
REGIONAL RADARS SHOW AN ACTIVE CONVECTIVE PATTERN OVER THE COASTAL
WATERS THIS MORNING ASSOCIATED WITH ILL-DEFINED LAND BREEZE
CONVERGENCE. LOTS OF SHOWERS OUT THERE WITH A FEW STORMS PRODUCING
FREQUENT LIGHTNING FROM TIME TO TIME. MARINERS HEADING OUT THIS
MORNING SHOULD BE PREPARED FOR THE OCCASIONAL SHOWER AND BE ON THE
LOOKOUT FOR BRIEF WATERSPOUT SPIN-UPS. THESE STORMS ARE MEANDERING
JUST OFF THE COAST WITH THE OCCASIONAL CELL MAKING A MOVE TOWARD THE
BEACHES. THIS TREND SHOULD CONTINUE FOR THE NEXT FEW HOUR...WITH A
GRADUAL DECREASE IN COVERAGE OVER THE WATER AS THE SEA-BREEZE BEGINS
TO ESTABLISH ITSELF...AND THEN A GRADUAL INCREASE IN CONVECTIVE
COVERAGE OVER THE LAND.
AWAY FROM THE IMMEDIATE COAST...SEVERAL MORE HOURS OF DRY CONDITIONS
ARE EXPECTED AS TEMPERATURES WARM THROUGH THE 80S. THE SUBTROPICAL
RIDGE POSITION OVER THE SOUTHERN PENINSULA SUGGEST GENERALLY LIGHT
FLOW WITH A SYNOPTIC PUSH FROM THE SW. THIS PUSH WILL BE STRONGEST
ACROSS THE NATURE COAST...AWAY FROM THE RIDGE AXIS. THIS "PUSH" WILL
HELP THE FEEBLE SEA-BREEZE WITH SOME INLAND PENETRATION FOR THE
LATER AFTERNOON HOURS. THEREFORE...WOULD EXPECT EARLY/MID AFTERNOON
STORMS TO BE POSSIBLE JUST ABOUT ANYWHERE...WITH THE TREND FOR
HIGHER COVERAGE DURING THE SECOND HALF OF THE AFTERNOON SHIFTING TO
THE I-75 CORRIDOR AND FURTHER INLAND. EXPECT STORMS TO BE RATHER
ISOLATED TOWARD THE BEACHES WITH THE MORE DIVERGENT AND SUBSIDENCE
DOMINATED FLOW IN THE WAKE OF THE SEA-BREEZE FOR THE LATER PART OF
THE DAY.
TONIGHT...EVENING STORMS FADE WITH SUNSET...SETTING UP A MOSTLY DRY
PERIOD OVER THE INTERIOR. SUBTROPICAL RIDGE AXIS SHIFTS JUST A TAD
FURTHER NORTH. GFS/NAM/SREF ALL SHOWING AN AXIS OF SURFACE
CONVERGENCE DEVELOPING FROM THE NATURE COAST SOUTHWEST TO THE WATERS
WEST OF TAMPA BAY. THIS BAND OF CONVERGENCE SHOULD IT MATERIALIZE
WOULD BE ENOUGH TO GET AN ACTIVE AREA OF SHALLOW CONVECTION GOING
OVER THE NORTHERN HALF OF THE WATERS...AND THE FLOW WOULD TEND TO
BRING THIS ACTIVITY TOWARD THE COAST AFTER MIDNIGHT. THEREFORE WILL
FAVOR PINELLAS COUNTY NORTHWARD FOR PRE-DAWN/EARLY SUNDAY MORNING
SCT STORMS MIGRATING TO THE COAST IN THE POP GRIDS. CURRENTLY
SHOWING 30% POPS FOR THIS FAVORED AREA...BUT WILL TAKE A CLOSE LOOK
AT THIS CONVERGENT FEATURE IN THE 12Z NWP PACKAGE AND SEE IF HIGHER
RAIN CHANCES MAY BE MORE APPROPRIATE.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING. ACTIVE
OFFSHORE STORMS ARE VISIBLE TO THE WEST OF MANY OF THE
TERMINALS...BUT FOR THE NEXT SEVERAL HOURS SHOULD GENERALLY STAY
AWAY. ONLY EXCEPTIONS MAY BE KSRQ AND KPIE SHOULD AN ISOLATED STORM
MIGRATING ONSHORE MAY FIND ITSELF IN THE VICINITY OF THE TERMINAL.
THEREAFTER STORM COVERAGE WILL INCREASE BY EARLY AFTERNOON AND THEN
TEND TO PUSH INLAND TO I-75 AND EASTWARD BY THE SECOND HALF OF THE
AFTERNOON.
&&
.MARINE...
HIGH PRESSURE ACROSS FLORIDA AND THE GULF WATERS WILL KEEP LIGHT
WEST TO SOUTHWEST WINDS IN PLACE INTO NEXT WEEK WITH SEAS 2 FEET
OR LESS. SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE
OVERNIGHT AND EARLY MORNING HOURS OVER THE GULF AND COASTAL
REGIONS AND MOVE INLAND EACH AFTERNOON. THESE STORMS WILL PRODUCE
LOCALLY HIGHER WINDS AND SEAS WITH A POTENTIAL FOR ISOLATED
WATERSPOUTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 79 88 79 / 40 20 30 10
FMY 89 76 90 77 / 50 20 30 20
GIF 89 77 89 76 / 60 30 50 20
SRQ 89 78 89 78 / 30 20 30 10
BKV 90 74 89 73 / 40 20 40 20
SPG 88 81 88 81 / 30 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1154 PM EDT SUN AUG 10 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH TUESDAY RESULTING IN NUMEROUS SHOWERS AND THUNDERSTORMS.
DRIER AIR WILL WORK INTO THE REGION MID WEEK AND LOWER RAIN
CHANCES.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
CONVERGENCE ASSOCIATED WITH THE STALLED FRONT AND HIGH MOISTURE
WILL SUPPORT A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS
OVERNIGHT. HOWEVER...EXPECT LITTLE COVERAGE BASED ON RADAR TRENDS
AND NOCTURNAL COOLING. THE LATEST HRRR DISPLAYS JUST ISOLATED
COVERAGE.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH MONDAY NIGHT. THE MODELS SHOW PRECIPITABLE WATER OVER 2
INCHES. CONVERGENCE ASSOCIATED WITH THE FRONT AND HIGH MOISTURE
SHOULD SUPPORT SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN POSSIBLE
ONCE AGAIN. THE PATTERN SUPPORTS THE HIGHER GUIDANCE MONDAY
THROUGH MONDAY NIGHT. THE NAM AND GFS INDICATE THE H85 FLOW
BECOMING MORE WESTERLY MONDAY NIGHT. CONVERGENCE MAY DIMINISH AND
WITH NOCTURNAL COOLING THE NAM AND GFS MOS APPEAR REASONABLE WITH
POPS LOWERING TO AROUND 30 PERCENT. USED THE COOLER HIGH
TEMPERATURE GUIDANCE AND WARMER LOW TEMPERATURE GUIDANCE BECAUSE
OF CLOUDINESS THROUGH THE PERIOD...WHICH HAS BEEN THE TREND.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS INDICATE THAT A FRONT WILL BE MOVING THROUGH THE CWA ON
WEDNESDAY...THEN STALLING ACROSS THE SRN PORTION OF THE CWA OR
JUST TO THE SOUTH. THIS WILL ALLOW THE CWA TO DRY OUT SOMEWHAT AS
PW VALUES DROP BELOW 1.5 INCHES. THE GFS AND ECMWF DISPLAY THE
STALLED FROM OR TROUGH TO REMAIN IN THE VICINITY OF THE FORECAST
AREA THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW
DEEPER MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. LEANED
TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS FOR THE POP
FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR IFR/LIFR CONDITIONS OVERNIGHT INTO MONDAY
MORNING.
FRONTAL BOUNDARY STALLED IN THE CSRA WITH WEDGE CONDITIONS NORTH
OF THE BOUNDARY. WINDS NORTHEAST 5 KNOTS OR LESS OVERNIGHT.
WIDESPREAD MVFR CIGS. HIGH LOW-LEVEL MOISTURE AND NOCTURNAL
COOLING WILL RESULT IN IFR/LIFR CONDITIONS. MODELS INDICATE CIGS
LIFTING TO MVFR LATE MONDAY MORNING. LOW CONFIDENCE IN TIMING OF
CIGS LIFTING. AS LOW CLOUDS BEGIN TO BREAK UP MONDAY
AFTERNOON...DIURNAL CONVECTION WILL ONCE AGAIN DEVELOP.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING MVFR TO IFR
RESTRICTIONS IN LOW CLOUDS AND/OR FOG EXPECTED...ALONG WITH HIGH
CHANCES OF MAINLY DIURNAL THUNDERSTORMS THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
711 AM EDT SAT AUG 9 2014
...HEAVY RAINS AND SHALLOW COASTAL FLOODING LIKELY AGAIN THIS
AFTERNOON AND EVENING...
.SYNOPSIS...
A STATIONARY FRONT WILL LIFT NORTH OF THE REGION TODAY...BUT
REMAIN NEARBY INTO EARLY NEXT WEEK. A COLD FRONT WILL THEN CROSS
THE REGION BY LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVECTION IS STEADILY EXPANDING OVER THE ERN SC MIDLANDS INTO
CNTRL GA. ADJUSTED NEAR TERM POPS ACROSS THE WRN ZONES TO ACCOUNT
FOR THIS. THE REMAINDER OF THE FCST LOOKS ON TRACK.
09/10Z SFC OBSERVATIONS AND STREAMLINE ANALYSIS INDICATE THE WMFNT
IS MEANDERING N...BEING AIDED BY STEADY PRES FALLS OVR THE SC
MIDLANDS AND NC PIEDMONT. MODELS SHOW THE FNT LIFTING N OF THE
FCST AREA LTR TDA AND BECMG STNRY ONCE AGAIN OVR THE NRN MIDLANDS
AND PEE DEE. IT LOOKS TO BE ANOTHER CONVECTIVELY ACTIVE DAY WITH A
PLUME OF DEEP MOISTURE FEATURING PWATS WELL IN EXCESS OF 2 INCHES
INTERACTING WITH A NUMBER OF WAVES OF UPSTREAM MID-LVL VORTICITY
AND MOD SFC BASED INSTAB. A NUMBER OF THE HIGH RESOLUTION
MODELS...INCLUDING THE RAP AND NSSL 4KM-WRF...INDICATE SHWRS/TSTMS
WL INITIATE OVR THE CNTRL AND WRN PARTS OF THE FCST AREA BY LTE
MRNG ONCE CONVECTIVE TEMPS IN THE MID 80S ARE BREACHED...THEN
SPREAD E TO THE COAST THROUGH THE AFTN PSBLY IN THE FORM OF
SEVERAL LINES OF STRONG TSTMS. POPS WL BE INCRD TO 70 PCNT ACROSS
ALL ZONES WITH THE CORE OF THE HIGHEST GRIDDED POPS SHIFTING FROM
W-E TO THE COAST DURING THE MID-LTE AFTN HRS. HIGHS WL BE TEMPERED
SOMEWHAT BY EXTENSIVE CLOUD COVER...BUT SHOULD STILL REACH THE UPR
80S N TO LWR 90S BEFORE THE ONSET OF TSTMS.
THERE WL BE A RISK FOR HVY RNFL AGAIN TDA...ESP DURING THE AFTN
HRS. FCST SOUNDINGS DEPICT FAIRLY WK FLOW IN THE 925-700 HPA LYR
WITH WND FIELDS FAVORING CONVECTIVE TRAINING/BACK-BUILDING...ESP
ALONG/NEAR MESOSCALE BNDRYS. 09/00Z FLASH FLOOD GUIDANCE IS RATHER
LOW IN A NUMBER OF LOCALES WHERE HVY RAIN FELL YDA SO THERE WL BE
A RISK FOR AT LEAST ISOLD FLASH FLOODING. THE RISK WL BE ELEVATED
AT THE COAST LTE THIS AFTN AS ALREADY ELEVATED TIDES WL BE HEADING
INTO THE ERLY EVNG HIGH TIDE CYCLE. WE STRONGLY CONSIDERED THE
ISSUANCE OF FLASH FLOOD WATCH FOR ALL THE COASTAL ZONES FROM LTE
AFTN INTO THE MID-EVNG HRS...BUT CONFIDENCE IS NOT HIGH ENOUGH
THIS FAR OUT THAT THE CORE OF THE HEAVIEST RAINS WILL FALL WITHIN
A FEW HRS EITHER SIDE OF HIGH TIDE. IF THE LATEST RUN OF THE 4KM-
NSSL WRF PLAYS OUT...THERE COULD VERY WELL BE FLASH FLOODING IN
BOTH THE SAVANNAH AND CHARLESTON AREAS LTE THIS AFTN. THIS WL BE
MONITORED THROUGHOUT THE DAY. IN ADDITION TO HVY RNFL.. THERE WL
BE A RISK FOR ISOLD STRONG/SVR TSTMS. 0-6KM BULK SHEAR IS FCST TO
REMAIN LESS THAN 15 KT SO THE RISK FOR ORGANIZED SVR TSTMS IS
LOW...ALTHOUGH A FEW LOOSELY ORGANIZED MULTI-CELLULAR CONVECTIVE
CLUSTERS COULD OCCUR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...CONVECTION WL SLOWLY WIND DOWN WITH THE LOSS OF
INSOLATION. LINGERING BNDRYS...HIGH PWATS AND SOME SFC BASED
INSTAB WL KEEP A RISK FOR SHWRS/TSTMS GOING THROUGH THE NGT. THERE
WL STILL BE A RISK FOR FLASH FLOODING...ESP AT THE COAST DURING
THE ERLY EVNG HIGH TIDE CYCLE. LOWS WL RANGE FROM THE LWR-MID 70S
INLAND MID-UPR 70S AT THE COAST.
SUNDAY...THE WEAK FRONT WILL MEANDER NORTH AS THE DAY PROGRESSES.
AT THE SAME TIME...SHORTWAVE ACTIVITY MOVING ACROSS THE CAROLINAS
TOWARD THE COASTLINE WILL PROVIDE THE NECESSARY ENERGY TO DEVELOP
A WEAK WAVE OF LOW PRESSURE ALONG THE BOUNDARY. THESE SYNOPTIC
SCALE FEATURES WILL HELP MAINTAIN DEEP LAYER MOISTURE ACROSS MUCH
OF THE SOUTHEAST STATES...WITH CONSIDERABLY HIGH PRECIPITABLE
WATER VALUES IN THE 2.25 TO 2.5 INCH RANGE. EXPECT SCATTERED TO
NUMEROUS THUNDERSTORM COVERAGE DURING THE DAYTIME HOURS AS A
RESULT. RAIN CHANCES WILL PEAK IN THE LIKELY RANGE ACROSS
NORTHERN AND INLAND LOCATIONS CLOSEST TO FORCING ALONG THE FRONTAL
ZONE AND THE TRANSIENT SHORTWAVE ENERGY. CONSIDERING THE HIGH
MOISTURE CONTENT OF THE ATMOSPHERE...THUNDERSTORMS WILL PRODUCE
HEAVY DOWNPOURS AND COULD CREATE LOCALIZED FLOODING ISSUES WHERE
STORM MOTION IS SLOWED BY BOUNDARY INTERACTIONS. ALTHOUGH
ORGANIZED SEVERE THUNDERSTORM DEVELOPMENT IS NOT EXPECTED WITHIN
SUCH A WARM AND SATURATED ENVIRONMENT...AN ISOLATED PULSE SEVERE
STORM COULD STILL OCCUR GIVEN MODERATE INSTABILITY. HIGH
TEMPERATURES WILL BE RIGHT AROUND SEASONAL NORMALS IN THE LOW 90S
INLAND UNDER MOSTLY CLOUDY SKIES. HAVE MAINTAINED A CHANCE OF
SHOWERS/THUNDERSTORMS INTO THE OVERNIGHT PERIOD TO ACCOUNT FOR
LINGERING SYNOPTIC SCALE FORCING...EVEN AFTER INSTABILITY
DIMINISHES WITH SUNSET.
MONDAY AND TUESDAY...THE QUASI-STATIONARY FRONT WILL BE LINGERING
ALONG THE NORTHERN PERIPHERY OF THE FORECAST AREA INTO EARLY NEXT
WEEK. THE CO-LOCATED WAVE OF LOW PRESSURE WILL DEEPEN SLIGHTLY ON
MONDAY...THEN LIFT NORTH/NORTHEAST INTO THE ATLANTIC WATERS
TUESDAY DOWNSTREAM OF A MORE AMPLIFIED UPPER TROUGH AXIS
SHIFTING TOWARD THE EAST COAST. WILL CONTINUE TO INDICATE HIGHER
THAN NORMAL RAIN CHANCES EACH DAY DUE TO PERSISTENT FORCING WITHIN
THE WEAK FRONT AND SURFACE WAVE...WITH POPS PEAKING IN THE 40
PERCENT RANGE DURING THE AFTERNOON HOURS AND DIMINISHING FROM WEST
TO EAST EACH NIGHT. PRECIPITABLE WATER VALUES WILL STILL BE AT OR
ABOVE 2 INCHES...THUS EXPECT DECENT COVERAGE OF THUNDERSTORMS AND
THE CONTINUED POTENTIAL FOR HEAVY DOWNPOURS WITHIN STRONGEST
CONVECTION. HIGH AND LOW TEMPERATURES WILL VARY LITTLE FROM DAY TO
DAY...WARMING INTO THE LOW 90S AWAY FROM THE COOLER COASTLINE AND
FALLING INTO THE LOW TO MID 70S EACH NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE FORECAST AREA WILL GENERALLY REMAIN BETWEEN A BROAD UPPER
TROUGH CENTERED TO THE NORTH AND UPPER LEVEL RIDGING SUPPRESSED
TO THE SOUTH OVER FLORIDA AND THE BAHAMAS. A WAVE OF SURFACE LOW
PRESSURE WILL BE LIFTING NORTH OFF THE NORTH CAROLINA/VIRGINIA
COASTLINE BY TUESDAY NIGHT...WITH A MORE WELL-DEFINED COLD FRONT
PROGRESSING EAST FROM THE OHIO/TENNESSEE VALLEYS IN ITS WAKE.
NOTABLY DRIER AIR WILL ACCOMPANY THE FRONT AS IT SHIFTS TOWARD
THE SOUTHEAST COAST BY THURSDAY AND POSSIBLY STALLS/DISSIPATES TO
THE EAST/SOUTHEAST FRIDAY. HAVE INDICATED HIGHEST RAIN CHANCES OF
THE EXTENDED PERIOD ON WEDNESDAY...BEFORE THE BAND OF DEEP
MOISTURE DISSIPATES OVER THE REGION AHEAD OF THE APPROACHING
FRONTAL SYSTEM. HAVE THEN TRENDED RAIN CHANCES BACK DOWN TOWARD
MORE SEASONAL 20 TO 30 PERCENT FOR THURSDAY THROUGH
SATURDAY...WITH BEST THUNDERSTORM POTENTIAL DURING THE
CLIMATOLOGICALLY FAVORED AFTERNOON TIME FRAME. EXPECT LITTLE
VARIATION IN THE HIGH TEMPERATURES EACH DAY...WITH TEMPERATURES
PEAKING IN THE LOWER 90S INLAND EACH AFTERNOON.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
IFR/LIFR CONDITIONS HAVE REMAINED JUST WEST OF THE KSAV TERMINAL.
AMENDED TO REMOVE IFR CONDITIONS. CONFIDENCE IS INCRG THAT TSTMS
WL IMPACT BOTH TERMINALS THIS AFTN. ALREADY SEEING TSTMS INCRG
ACROSS THE SRN MIDLANDS INTO CNTRL GA. THE 12Z TAFS WL FEATURE
PREVAILING MVFR CONDITIONS IN TSTMS AT BOTH TERMINALS...BEGINNING
AT 18Z AT KSAV AND 19Z AT KCHS WITH TEMPO GROUPS SHOWING LOW-END
MVFR CONDITIONS. BRIEF STINTS OF IFR OR EVEN LIFR ARE PSBL IN
HEAVY RAIN...BUT STILL A BIT TOO FAR TO INCLUDE THOSE CONDITIONS
JUST YET. TIMING IS STILL A BIT UNCERTAIN SO AMENDMENTS WL MOST
CERTAINLY BE NEEDED AS THE DAY PROGRESSES. THERE WL BE A RISK FOR
SHWR/TSTM ACTIVITY FOR MUCH OF THE OVRNGT HRS...ESP AT KCHS AS A
FNTL BNDRY SINKS BACK TO THE S. ADDITIONAL MENTIONS OF SHWRS AND
TSTMS MAY EVENTUALLY BE NEEDED.
EXTENDED AVIATION OUTLOOK...EXPECT SCATTERED AND MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS...WITH BRIEF PERIODS OF FLIGHT
RESTRICTIONS THROUGH WEDNESDAY.
&&
.MARINE...
TODAY...WNDS WL TURN ONSHORE BY THIS AFTN AS THE WMFNT LIFTS N OF
THE WTRS. SPEEDS SHOULD TOP OUT AT 5-10 KT...PSBLY A LITTLE HIGHER
NEAR THE COAST AND IN THE CHARLESTON HARBOR. SEAS WL AVG 1-3 FT.
TONIGHT...WNDS ARE FCST TO BACK TO THE S WITH SPEEDS AROUND 10
KT. SEAS WL REMAIN 1-3 FT.
SUNDAY THROUGH WEDNESDAY....A WEAK FRONT WILL LIFT SLIGHTLY TO
THE NORTH BY SUNDAY...WHILE A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE MEANDERING BOUNDARY AND SHIFTS EAST/NORTHEAST INTO THE
ATLANTIC MONDAY AND TUESDAY. ALTHOUGH THERE COULD BE A SLIGHT
TIGHTENING OF THE GRADIENT TUESDAY TO THE SOUTH OF THE LIFTING
SURFACE LOW...WIND SPEEDS ARE STILL EXPECTED TO GENERALLY REMAIN
ON EITHER SIDE OF 15 KT WITH SEAS 2 TO 4 FT THROUGH THE PERIOD.
&&
.TIDES/COASTAL FLOODING...
CURRENT AND FCST TIDAL DEPARTURES SUGGEST TIDES WILL APRCH/EXCEED
MODERATE COASTAL FLOODING THRESHOLDS FOR THE LWR SC COAST AND
SHALLOW COASTAL FLOODING THRESHOLDS FOR THE UPR GA COAST. XPCT
TIDES OF 7.3-7.6 FT MLLW IN THE CHARLESTON HARBOR WITH 9.1 TO 9.4
FT MLLW AT FT PULASKI. COMPLICATING MATTERS IS HVY RAIN COULD BE
FALLING AROUND THE TIME OF HIGH TIDE THIS EVNG. WL ISSUE A COASTAL
FLOOD ADV FOR ALL COASTAL ZONES...INCLUDING TIDAL BERKELEY...FROM
6PM-10PM.
THE PROXIGEAN SPRING TIDE...THE FULL MOON COINCIDENT WITH THE
CLOSEST LUNAR PERIGEE OF THE YEAR...WILL PEAK THIS WEEKEND AND
CREATE HIGHER THAN NORMAL ASTRONOMICAL TIDES. SINCE ONLY SMALL
DEPARTURES ARE NEEDED ABOVE THE PREDICTED ASTRONOMICAL TIDE VALUES
TO RESULT IN MINIMAL COASTAL FLOODING...EVEN WITH A RATHER WEAK
ONSHORE FLOW THIS WILL STILL LIKELY BOOST TIDE LEVELS ABOVE
CRITICAL THRESHOLDS. THE BEST CHANCE FOR COASTAL FLOOD ADVISORIES
WOULD BE DURING THE EVENING HIGH TIDES INTO EARLY NEXT WEEK. AS
ALWAYS...IF HEAVY RAIN OCCURS AROUND THE TIMES OF THE ELEVATED
HIGH TIDES...RUNOFF WILL BE INHIBITED AND MORE SIGNIFICANT
FLOODING COULD OCCUR WITHIN COASTAL COMMUNITIES.
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT THIS EVENING FOR
GAZ117-119-139-141.
SC...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT THIS EVENING FOR
SCZ048>052.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
349 AM EDT SAT AUG 9 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH THE EARLY PART OF NEXT WEEK. THE FRONT WILL BRING
NUMEROUS SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY MORNING HOURS...CONVERGENCE INTO THE STALLED FRONT WILL SUPPORT
ADDITIONAL SHOWERS OR THUNDERSTORMS BUT COVERAGE SHOULD BE LIMITED
BECAUSE OF DIMINISHED INSTABILITY FROM PREVIOUS CONVECTION AND
NOCTURNAL COOLING. THE LATEST HRRR SUPPORTS SCATTERED COVERAGE
WITH SOME INCREASE IN THE NORTH PART TOWARD SUNRISE. CONTINUED
HIGH PRECIPITABLE WATER SUPPORTS A THREAT OF HEAVY RAIN WITH SOME
OF THE SHOWERS.
TODAY AND TONIGHT...CONVERGENCE INTO THE FRONTAL BOUNDARY WILL
SUPPORT NUMEROUS SHOWERS AND THUNDERSTORMS. THE MODELS DISPLAY THE
GREATEST MOISTURE AND ISENTROPIC LIFT IN THE NORTH PART OF THE
FORECAST AREA. HOWEVER...THE SPC WRF SHOWS THE GREATEST
THUNDERSTORM COVERAGE IN THE SOUTH PART OF THE FORECAST AREA LATE
THIS AFTERNOON. WE HAVE FORECASTED LIKELY POPS ACROSS THE AREA.
PRECIPITABLE WATER WILL REMAIN JUST ABOVE 2 INCHES. THE MODELS
SHOW A DIFLUENT 1000-500 MB THICKNESS PATTERN WITH A DEPTH NEAR
574 DAM. THIS IS A PREFERRED VALUE FOR HEAVY RAIN IN AUGUST. SOME
OF THE THUNDERSTORMS COULD POSSIBLE BRING LOCALIZED FLOODING. HEAVY
PRECIPITATION LOADING MAY HELP SUPPORT STRONG WIND GUSTS AS WELL.
LEANED TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE BECAUSE OF
CLOUDINESS AND SHOWERS. USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH SUNDAY NIGHT. HIGH MOISTURE AND CONVERGENCE ASSOCIATED
WITH THE FRONT SUPPORT THE HIGHER GUIDANCE POPS ESPECIALLY IN THE
NORTH SECTION WHERE THE MODELS INDICATE STRONGER CONVERGENCE AND
DEEPER MOISTURE. LOCALLY HEAVY RAIN MAY OCCUR WITH PRECIPITABLE
WATER JUST OVER 2 INCHES AND A DIFLUENT 1000-500 MB THICKNESS
PATTERN WITH DEPTHS NEAR 574 DAM WHICH FAVORS HEAVY RAIN IN
AUGUST. LEANED TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE AND
WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY A STALLED FRONT OR TROUGH IN THE FORECAST AREA
THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW DEEPER
MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. THE MODELS INDICATE HIGH
PRECIPITABLE WATER AND A CONTINUED THREAT OF HEAVY RAIN EARLY IN
THE PERIOD. LEANED TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD
MOS FOR THE POP FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR
CLIMATOLOGY.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AMPLE LOW-LEVEL MOISTURE AND LIGHT WIND SHOULD SUPPORT FOG AND
IFR CIGS DURING THE EARLY MORNING HOURS.
HEATING LATER THIS MORNING SHOULD HELP SUPPORT MVFR OR VFR
CONDITIONS. HOWEVER...IFR CONDITIONS WILL OCCUR AT TIMES IN SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE LOWER RESTRICTIONS WERE
NOT INCLUDED IN THE FORECAST BECAUSE OF TIMING UNCERTAINTY AT THIS
TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SUNDAY MORNING
THROUGH TUESDAY IN SHOWERS AND THUNDERSTORMS AS A LOW PRESSURE
SYSTEM SLOWLY CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
346 AM EDT SAT AUG 9 2014
...HEAVY RAINS AND SHALLOW COASTAL FLOODING LIKELY AGAIN THIS
AFTERNOON AND EVENING...
.SYNOPSIS...
A STATIONARY FRONT WILL LIFT NORTH OF THE REGION TODAY...BUT
REMAIN NEARBY INTO EARLY NEXT WEEK. A COLD FRONT WILL THEN CROSS
THE REGION BY LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
09/06Z SFC OBSERVATIONS AND STREAMLINE ANALYSIS INDICATE THE WMFNT
IS LIFTING SLOWLY N...BEING AIDED BY STEADY PRES FALLS OVR THE SC
MIDLANDS AND NC PIEDMONT. MODELS SHOW THE FNT LIFTING N OF THE
FCST AREA LTR THIS MRNG AND BECMG STNRY ONCE AGAIN NEAR THE
NC/SC BORDER. IT LOOKS TO BE ANOTHER CONVECTIVELY ACTIVE DAY WITH
A PLUME OF DEEP MOISTURE FEATURING PWATS WELL IN EXCESS OF 2
INCHES INTERACTING WITH A NUMBER OF WAVES OF UPSTREAM MID-LVL
VORTICITY AND MOD SFC BASED INSTAB. A NUMBER OF THE HIGH RESOLUTION
MODELS...INCLUDING THE RAP AND NSSL 4KM-WRF...INDICATE
SHWRS/TSTMS WL INITIATE OVR THE CNTRL AND WRN PARTS OF THE FCST
AREA BY LTE MRNG ONCE CONVECTIVE TEMPS IN THE MID 80S ARE
BREACHED...THEN SPREAD E TO THE COAST THROUGH THE AFTN PSBLY IN
THE FORM OF SEVERAL LINES OF STRONG TSTMS. POPS WL BE INCRD TO 70
PCNT ACROSS ALL ZONES WITH THE CORE OF THE HIGHEST GRIDDED POPS
SHIFTING FROM W-E TO THE COAST DURING THE MID-LTE AFTN HRS. HIGHS
WL BE TEMPERED SOMEWHAT BY EXTENSIVE CLOUD COVER...BUT SHOULD
STILL REACH THE UPR 80S N TO LWR 90S BEFORE THE ONSET OF TSTMS.
THERE WL BE A RISK FOR HVY RNFL AGAIN TDA...ESP DURING THE AFTN
HRS. FCST SOUNDINGS DEPICT FAIRLY WK FLOW IN THE 925-700 HPA LYR
WITH WND FIELDS FAVORING CONVECTIVE TRAINING/BACK-BUILDING...ESP
ALONG/NEAR MESOSCALE BNDRYS. 09/00Z FLASH FLOOD GUIDANCE IS RATHER
LOW IN A NUMBER OF LOCALES WHERE HVY RAIN FELL YDA SO THERE WL BE
A RISK FOR AT LEAST ISOLD FLASH FLOODING. THE RISK WL BE ELEVATED
AT THE COAST LTE THIS AFTN AS ALREADY ELEVATED TIDES WL BE HEADING
INTO THE ERLY EVNG HIGH TIDE CYCLE. WE STRONGLY CONSIDERED THE
ISSUANCE OF FLASH FLOOD WATCH FOR ALL THE COASTAL ZONES FROM LTE
AFTN INTO THE MID-EVNG HRS...BUT CONFIDENCE IS NOT HIGH ENOUGH
THIS FAR OUT THAT THE CORE OF THE HEAVIEST RAINS WILL FALL WITHIN
A FEW HRS EITHER SIDE OF HIGH TIDE. IF THE LATEST RUN OF THE 4KM-
NSSL WRF PLAYS OUT...THERE COULD VERY WELL BE FLASH FLOODING IN
BOTH THE SAVANNAH AND CHARLESTON AREAS LTE THIS AFTN. THIS WL BE
MONITORED THROUGHOUT THE DAY. IN ADDITION TO HVY RNFL.. THERE WL
BE A RISK FOR ISOLD STRONG/SVR TSTMS. 0-6KM BULK SHEAR IS FCST TO
REMAIN LESS THAN 15 KT SO THE RISK FOR ORGANIZED SVR TSTMS IS
LOW...ALTHOUGH A FEW LOOSELY ORGANIZED MULTI-CELLULAR CONVECTIVE
CLUSTERS COULD OCCUR.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
TONIGHT...CONVECTION WL SLOWLY WIND DOWN WITH THE LOSS OF
INSOLATION. LINGERING BNDRYS...HIGH PWATS AND SOME SFC BASED
INSTAB WL KEEP A RISK FOR SHWRS/TSTMS GOING THROUGH THE NGT. THERE
WL STILL BE A RISK FOR FLASH FLOODING...ESP AT THE COAST DURING
THE ERLY EVNG HIGH TIDE CYCLE. LOWS WL RANGE FROM THE LWR-MID 70S
INLAND MID-UPR 70S AT THE COAST.
SUNDAY...THE WEAK FRONT WILL MEANDER NORTH AS THE DAY PROGRESSES.
AT THE SAME TIME...SHORTWAVE ACTIVITY MOVING ACROSS THE CAROLINAS
TOWARD THE COASTLINE WILL PROVIDE THE NECESSARY ENERGY TO DEVELOP
A WEAK WAVE OF LOW PRESSURE ALONG THE BOUNDARY. THESE SYNOPTIC
SCALE FEATURES WILL HELP MAINTAIN DEEP LAYER MOISTURE ACROSS MUCH
OF THE SOUTHEAST STATES...WITH CONSIDERABLY HIGH PRECIPITABLE
WATER VALUES IN THE 2.25 TO 2.5 INCH RANGE. EXPECT SCATTERED TO
NUMEROUS THUNDERSTORM COVERAGE DURING THE DAYTIME HOURS AS A
RESULT. RAIN CHANCES WILL PEAK IN THE LIKELY RANGE ACROSS
NORTHERN AND INLAND LOCATIONS CLOSEST TO FORCING ALONG THE FRONTAL
ZONE AND THE TRANSIENT SHORTWAVE ENERGY. CONSIDERING THE HIGH
MOISTURE CONTENT OF THE ATMOSPHERE...THUNDERSTORMS WILL PRODUCE
HEAVY DOWNPOURS AND COULD CREATE LOCALIZED FLOODING ISSUES WHERE
STORM MOTION IS SLOWED BY BOUNDARY INTERACTIONS. ALTHOUGH
ORGANIZED SEVERE THUNDERSTORM DEVELOPMENT IS NOT EXPECTED WITHIN
SUCH A WARM AND SATURATED ENVIRONMENT...AN ISOLATED PULSE SEVERE
STORM COULD STILL OCCUR GIVEN MODERATE INSTABILITY. HIGH
TEMPERATURES WILL BE RIGHT AROUND SEASONAL NORMALS IN THE LOW 90S
INLAND UNDER MOSTLY CLOUDY SKIES. HAVE MAINTAINED A CHANCE OF
SHOWERS/THUNDERSTORMS INTO THE OVERNIGHT PERIOD TO ACCOUNT FOR
LINGERING SYNOPTIC SCALE FORCING...EVEN AFTER INSTABILITY
DIMINISHES WITH SUNSET.
MONDAY AND TUESDAY...THE QUASI-STATIONARY FRONT WILL BE LINGERING
ALONG THE NORTHERN PERIPHERY OF THE FORECAST AREA INTO EARLY NEXT
WEEK. THE CO-LOCATED WAVE OF LOW PRESSURE WILL DEEPEN SLIGHTLY ON
MONDAY...THEN LIFT NORTH/NORTHEAST INTO THE ATLANTIC WATERS
TUESDAY DOWNSTREAM OF A MORE AMPLIFIED UPPER TROUGH AXIS
SHIFTING TOWARD THE EAST COAST. WILL CONTINUE TO INDICATE HIGHER
THAN NORMAL RAIN CHANCES EACH DAY DUE TO PERSISTENT FORCING WITHIN
THE WEAK FRONT AND SURFACE WAVE...WITH POPS PEAKING IN THE 40
PERCENT RANGE DURING THE AFTERNOON HOURS AND DIMINISHING FROM WEST
TO EAST EACH NIGHT. PRECIPITABLE WATER VALUES WILL STILL BE AT OR
ABOVE 2 INCHES...THUS EXPECT DECENT COVERAGE OF THUNDERSTORMS AND
THE CONTINUED POTENTIAL FOR HEAVY DOWNPOURS WITHIN STRONGEST
CONVECTION. HIGH AND LOW TEMPERATURES WILL VARY LITTLE FROM DAY TO
DAY...WARMING INTO THE LOW 90S AWAY FROM THE COOLER COASTLINE AND
FALLING INTO THE LOW TO MID 70S EACH NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE FORECAST AREA WILL GENERALLY REMAIN BETWEEN A BROAD UPPER
TROUGH CENTERED TO THE NORTH AND UPPER LEVEL RIDGING SUPPRESSED
TO THE SOUTH OVER FLORIDA AND THE BAHAMAS. A WAVE OF SURFACE LOW
PRESSURE WILL BE LIFTING NORTH OFF THE NORTH CAROLINA/VIRGINIA
COASTLINE BY TUESDAY NIGHT...WITH A MORE WELL-DEFINED COLD FRONT
PROGRESSING EAST FROM THE OHIO/TENNESSEE VALLEYS IN ITS WAKE.
NOTABLY DRIER AIR WILL ACCOMPANY THE FRONT AS IT SHIFTS TOWARD
THE SOUTHEAST COAST BY THURSDAY AND POSSIBLY STALLS/DISSIPATES TO
THE EAST/SOUTHEAST FRIDAY. HAVE INDICATED HIGHEST RAIN CHANCES OF
THE EXTENDED PERIOD ON WEDNESDAY...BEFORE THE BAND OF DEEP
MOISTURE DISSIPATES OVER THE REGION AHEAD OF THE APPROACHING
FRONTAL SYSTEM. HAVE THEN TRENDED RAIN CHANCES BACK DOWN TOWARD
MORE SEASONAL 20 TO 30 PERCENT FOR THURSDAY THROUGH
SATURDAY...WITH BEST THUNDERSTORM POTENTIAL DURING THE
CLIMATOLOGICALLY FAVORED AFTERNOON TIME FRAME. EXPECT LITTLE
VARIATION IN THE HIGH TEMPERATURES EACH DAY...WITH TEMPERATURES
PEAKING IN THE LOWER 90S INLAND EACH AFTERNOON.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
STARTING TO SEE LIFR/IFR CIGS DVLP ACROSS PARTS OF SE GA WHERE
SKIES HAVE TEMPORARILY CLEARED. ALREADY SEEING SCT004 AT KSAV PER
05Z OBSERVATION...SO WILL INCLUDE A TEMPO GROUP FOR 4SM BKN004
FROM ROUGHLY 07-10Z TO COVER POTENTIAL STRATUS FORMING. ENOUGH
CLOUD COVER SHOULD REMAIN AT KCHS TO PREVENT ANYTHING OTHER THAN
VFR. TSTMS MOVING UP THE LWR SC COAST LOOK TO REMAIN EAST OF
KCHS...BUT IT WL BE CLOSE. INCLUDED VCTS THROUGH 09Z TO COVER.
LOOKS TO BE ANOTHER ACTIVE DAY FOR SHOWERS/TSTMS ACROSS THE RGN.
HIGH RESOLUTION MODELS FEATURE LINES OF TSTMS AFFECTING BOTH
TERMINALS THIS AFTN. TIMING IS STILL A BIT UNCERTAIN THIS FAR
OUT...BUT INCLUDED TEMPO GROUPS FOR LOW-END MVFR TSTM CONDITIONS
AT KCHS FROM 19-22Z AND 18-21Z AT KSAV. ADJUSTMENTS WL BE NEEDED
AS THE DAY PROGRESSES.
EXTENDED AVIATION OUTLOOK...EXPECT SCATTERED AND MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS...WITH BRIEF PERIODS OF FLIGHT
RESTRICTIONS THROUGH WEDNESDAY.
&&
.MARINE...
TODAY...WNDS WL TURN ONSHORE BY THIS AFTN AS THE WMFNT LIFTS N OF
THE WTRS. SPEEDS SHOULD TOP OUT AT 5-10 KT...PSBLY A LITTLE HIGHER
NEAR THE COAST AND IN THE CHARLESTON HARBOR. SEAS WL AVG 1-3 FT.
TONIGHT...WNDS ARE FCST TO BACK TO THE S WITH SPEEDS AROUND 10
KT. SEAS WL REMAIN 1-3 FT.
SUNDAY THROUGH WEDNESDAY....A WEAK FRONT WILL LIFT SLIGHTLY TO
THE NORTH BY SUNDAY...WHILE A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE MEANDERING BOUNDARY AND SHIFTS EAST/NORTHEAST INTO THE
ATLANTIC MONDAY AND TUESDAY. ALTHOUGH THERE COULD BE A SLIGHT
TIGHTENING OF THE GRADIENT TUESDAY TO THE SOUTH OF THE LIFTING
SURFACE LOW...WIND SPEEDS ARE STILL EXPECTED TO GENERALLY REMAIN
ON EITHER SIDE OF 15 KT WITH SEAS 2 TO 4 FT THROUGH THE PERIOD.
&&
.TIDES/COASTAL FLOODING...
CURRENT AND FCST TIDAL DEPARTURES SUGGEST TIDES WILL APRCH/EXCEED
MODERATE COASTAL FLOODING THRESHOLDS FOR THE LWR SC COAST AND
SHALLOW COASTAL FLOODING THRESHOLDS FOR THE UPR GA COAST. XPCT
TIDES OF 7.3-7.6 FT MLLW IN THE CHARLESTON HARBOR WITH 9.1 TO 9.4
FT MLLW AT FT PULASKI. COMPLICATING MATTERS IS HVY RAIN COULD BE
FALLING AROUND THE TIME OF HIGH TIDE THIS EVNG. WL ISSUE A COASTAL
FLOOD ADV FOR ALL COASTAL ZONES...INCLUDING TIDAL BERKELEY...FROM
6PM-10PM.
THE PROXIGEAN SPRING TIDE...THE FULL MOON COINCIDENT WITH THE
CLOSEST LUNAR PERIGEE OF THE YEAR...WILL PEAK THIS WEEKEND AND
CREATE HIGHER THAN NORMAL ASTRONOMICAL TIDES. SINCE ONLY SMALL
DEPARTURES ARE NEEDED ABOVE THE PREDICTED ASTRONOMICAL TIDE VALUES
TO RESULT IN MINIMAL COASTAL FLOODING...EVEN WITH A RATHER WEAK
ONSHORE FLOW THIS WILL STILL LIKELY BOOST TIDE LEVELS ABOVE
CRITICAL THRESHOLDS. THE BEST CHANCE FOR COASTAL FLOOD ADVISORIES
WOULD BE DURING THE EVENING HIGH TIDES INTO EARLY NEXT WEEK. AS
ALWAYS...IF HEAVY RAIN OCCURS AROUND THE TIMES OF THE ELEVATED
HIGH TIDES...RUNOFF WILL BE INHIBITED AND MORE SIGNIFICANT
FLOODING COULD OCCUR WITHIN COASTAL COMMUNITIES.
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT THIS EVENING FOR
GAZ117-119-139-141.
SC...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT THIS EVENING FOR
SCZ048>052.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
230 AM EDT SAT AUG 9 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH THE EARLY PART OF NEXT WEEK. THE FRONT WILL BRING
NUMEROUS SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY MORNING HOURS...CONVERGENCE INTO THE STALLED FRONT WILL SUPPORT
ADDITIONAL SHOWERS OR THUNDERSTORMS BUT COVERAGE SHOULD BE LIMITED
BECAUSE OF DIMINISHED INSTABILITY FROM PREVIOUS CONVECTION AND
NOCTURNAL COOLING. THE LATEST HRRR SUPPORTS SCATTERED COVERAGE
WITH SOME INCREASE IN THE NORTH PART TOWARD SUNRISE. CONTINUED
HIGH PRECIPITABLE WATER SUPPORTS A THREAT OF HEAVY RAIN WITH SOME
OF THE SHOWERS.
TODAY AND TONIGHT...CONVERGENCE INTO THE FRONTAL BOUNDARY WILL
SUPPORT NUMEROUS SHOWERS AND THUNDERSTORMS. THE MODELS DISPLAY THE
GREATEST MOISTURE AND ISENTROPIC LIFT IN THE NORTH PART OF THE
FORECAST AREA. HOWEVER...THE SPC WRF SHOWS THE GREATEST
THUNDERSTORM COVERAGE IN THE SOUTH PART OF THE FORECAST AREA LATE
THIS AFTERNOON. WE HAVE FORECASTED LIKELY POPS ACROSS THE AREA.
PRECIPITABLE WATER WILL REMAIN JUST ABOVE 2 INCHES. THE MODELS
SHOW A DIFLUENT 1000-500 MB THICKNESS PATTERN WITH A DEPTH NEAR
574 DAM. THIS IS A PREFERRED VALUE FOR HEAVY RAIN IN AUGUST. SOME
OF THE THUNDERSTORMS COULD POSSIBLE BRING LOCALIZED FLOODING. HEAVY
PRECIPITATION LOADING MAY HELP SUPPORT STRONG WIND GUSTS AS WELL.
LEANED TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE BECAUSE OF
CLOUDINESS AND SHOWERS. USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH SUNDAY NIGHT. HIGH MOISTURE AND CONVERGENCE ASSOCIATED
WITH THE FRONT SUPPORT THE HIGHER GUIDANCE POPS ESPECIALLY IN THE
NORTH SECTION WHERE THE MODELS INDICATE STRONGER CONVERGENCE AND
DEEPER MOISTURE. LOCALLY HEAVY RAIN MAY OCCUR WITH PRECIPITABLE
WATER JUST OVER 2 INCHES AND A DIFLUENT 1000-500 MB THICKNESS
PATTERN WITH DEPTHS NEAR 574 DAM WHICH FAVORS HEAVY RAIN IN
AUGUST. LEANED TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE AND
WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY A STALLED FRONT OR TROUGH IN THE FORECAST AREA
THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW DEEPER
MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. THE MODELS INDICATE HIGH
PRECIPITABLE WATER AND A CONTINUED THREAT OF HEAVY RAIN EARLY IN
THE PERIOD. LEANED TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD
MOS FOR THE POP FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR
CLIMATOLOGY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS DURING THE EARLY
MORNING HOURS.
FIRST ROUND OF CONVECTION HAS EXITED THE MIDLANDS...WHILE WIDELY
SCATTERED CONVECTION IN CENTRAL GA MAY MOVE INTO THE AREA OVER THE
NEXT FEW HOURS. AMPLE LOW LEVEL MOISTURE AND LIGHT WIND SHOULD ALLOW
FOG AND IFR CIGS TO DEVELOP DURING THE EARLY MORNING HOURS.
CEILINGS SHOULD RISE DURING THE MORNING WITH MVFR/VFR CONDITIONS
AFTER 15Z. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED
TO AFFECT THE TAF SITES DURING THE DAY SATURDAY.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SUNDAY MORNING
THROUGH TUESDAY IN SHOWERS AND THUNDERSTORMS AS A LOW PRESSURE
SYSTEM SLOWLY CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
120 AM EDT SAT AUG 9 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH THE WEEKEND. THE FRONT WILL BRING NUMEROUS SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CONVERGENCE INTO THE STALLED FRONT SHOULD SUPPORT ADDITIONAL
SHOWERS OR THUNDERSTORMS OVERNIGHT BUT COVERAGE SHOULD BE LIMITED
BECAUSE OF THE DIMINISHED INSTABILITY FROM PREVIOUS CONVECTION AND
NOCTURNAL COOLING. THE LATEST HRRR SUPPORTS SCATTERED COVERAGE WITH SOME
INCREASE IN THE NORTH PART TOWARD SUNRISE. CONTINUED HIGH
PRECIPITABLE WATER OVERNIGHT SUPPORTS A THREAT OF HEAVY RAIN WITH
SOME OF THE SHOWERS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH SATURDAY NIGHT. HIGH MOISTURE AND CONVERGENCE ASSOCIATED
WITH THE FRONT SUPPORT THE HIGHER GUIDANCE POPS ESPECIALLY IN THE
NORTH SECTION WHERE THE MODELS INDICATE STRONGER CONVERGENCE AND
DEEPER MOISTURE. LOCALLY HEAVY RAIN MAY OCCUR WITH PRECIPITABLE
WATER JUST OVER 2 INCHES AND A DIFLUENT 1000-500 MB THICKNESS
PATTERN. THICKNESS VALUES NEAR 574 DAM IS A PREFERRED DEPTH FOR
HEAVY RAIN IN AUGUST. BASED ON GUIDANCE AND MODEL SPECTRUM DID
RAISE POPS SLIGHTLY THROUGH THE PERIOD. CONTINUED WITH THE COOLER
HIGH TEMPERATURE AND NEAR/SLIGHTLY ABOVE LOW TEMPERATURE GUIDANCE
DUE TO CLOUDINESS AND PRECIPITATION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY A STALLED FRONT WITH SIGNIFICANT
MOISTURE IN THE FORECAST AREA THROUGH THE MEDIUM-RANGE PERIOD. THE
GFS...ECMWF...AND EKE MOS POPS GENERALLY RANGE FROM 30 TO 60
PERCENT WITH THE HIGHEST CHANCES SUNDAY THEN GRADUALLY DECREASING
TO SLIGHT CHANCE BY THURSDAY AND FRIDAY. THE MODELS INDICATE
PRECIPITABLE WATER JUST OVER 2 INCHES SUNDAY THROUGH WEDNESDAY.
VALUES BEGIN TO DECREASE THURSDAY AND FRIDAY. THERE IS A THREAT OF
LOCALLY HEAVY RAIN MONDAY AND TUESDAY. THE GUIDANCE TEMPERATURES
ARE CLOSE TO CLIMATOLOGY DURING THE PERIOD WITH A SLIGHT WARMING
TREND THROUGH NEXT WEEK.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS DURING THE EARLY
MORNING HOURS.
FIRST ROUND OF CONVECTION HAS EXITED THE MIDLANDS...WHILE WIDELY
SCATTERED CONVECTION IN CENTRAL GA MAY MOVE INTO THE AREA OVER THE
NEXT FEW HOURS. AMPLE LOW LEVEL MOISTURE AND LIGHT WIND SHOULD ALLOW
FOG AND IFR CIGS TO DEVELOP DURING THE EARLY MORNING HOURS.
CEILINGS SHOULD RISE DURING THE MORNING WITH MVFR/VFR CONDITIONS
AFTER 15Z. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED
TO AFFECT THE TAF SITES DURING THE DAY SATURDAY.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SUNDAY MORNING
THROUGH TUESDAY IN SHOWERS AND THUNDERSTORMS AS A LOW PRESSURE
SYSTEM SLOWLY CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
114 PM CDT SAT AUG 9 2014
.DISCUSSION...
406 AM CDT
QUIET AND SEASONABLE WEATHER IS EXPECTED TO PERSIST THROUGH THE
WEEKEND...FOLLOWED BY INCREASED SHRA AND TSRA CHANCES MONDAY INTO
TUESDAY...THEN ANOTHER DRY PERIOD FOR THE LATTER HALF OF THE WEEK.
WITH THE GULF RETURN FLOW MOSTLY SHUT OFF...LOW LEVEL MOISTURE WILL
BE FAIRLY LIMITED THROUGH THE PERIOD...INHIBITING THE EFFECTS OF
FAVORABLE SHORTWAVE ENERGY ALOFT. HOWEVER...MODELS ARE SUGGESTING
THE PRESENCE OF SEVERAL SUCH WAVES...SO THERE IS A POSSIBILITY THAT
ONE OF THESE COULD BE POTENT ENOUGH AND TAP INTO JUST ENOUGH
MOISTURE TO TRIGGER AN ISOLATED BUT UNEXPECTED SHOWER OR
THUNDERSTORM WHEN MOST OF THE AREA REMAINS DRY.
A SURFACE LOW PASSING SOUTH OF THE AREA BRINGS THE BEST CHANCES OF
TSRA/SHRA MONDAY INTO MONDAY NIGHT. AGAIN...DUE TO LIMITED MOISTURE
IN THE EASTERLY FLOW AROUND THE NORTH SIDE OF THIS FEATURE...THERE
IS A QUESTION OF HOW FAR THE PRECIP SHIELD WILL SPREAD. THE CENTER
OF THE LOW ALSO COMES CLOSEST TO THE LOCAL AREA AT THE LEAST
FAVORABLE DIURNAL TIME...SUNDAY NIGHT INTO EARLY MONDAY MORNING.
BY MONDAY NIGHT INTO TUESDAY THE SURFACE LOW MOVES AWAY FROM THE
AREA...WRAPPING UP AND DEEPENING OVER THE OHIO VALLEY. THIS WILL
INCREASE THE CYCLONIC GRADIENT LOCALLY...TURN WINDS
NORTHWEST...LIKELY SUPPORT EXTENSIVE CLOUD COVER AND EVEN A FEW
SHOWERS...AND MAKE TUESDAY THE COOLEST AND BREEZIEST DAY OF THE
COMING WEEK.
AN APPROACHING RIDGE BEHIND THE DEPARTING LOW WILL AGAIN SUPPORT
CLEARING SKIES...LOWER PRECIP CHANCES...AND SLIGHTLY MODERATING
TEMPERATURES FOR WEDNESDAY AND THURSDAY.
FOR THURSDAY NIGHT AND FRIDAY...MODELS ARE SHOWING SOME DISAGREEMENT
IN HOW QUICKLY THE RIDGE BREAKS DOWN AND SLIDES AWAY TO THE EAST.
THERE IS A POSSIBILITY OF CONVECTIVE DEVELOPMENT DURING THIS PERIOD
ALONG A WARM FRONTAL FEATURE AHEAD OF THE NEXT APPROACHING LOW
PRESSURE SYSTEM...BUT FOR NOW HAVE ELECTED TO DOWNPLAY THE TSRA
CHANCES UNTIL IT BECOMES MORE CLEAR HOW QUICKLY THE RIDGE WILL
ACTUALLY DEPART.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST-NORTHEAST WINDS 11-13 KT WITH GUSTS 15-20 KT POSSIBLE
THROUGH SUNSET. NORTHEAST WINDS AROUND 10 KT SUNDAY AFTERNOON.
KMD
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE REMAINS IN CONTROL OF THE GREAT LAKES REGION WITH
WEAKENING LOW PRESSURE ENTERING THE OHIO VALLEY. THIS LEAVES MUCH
OF THE AREA IN A MODEST PRESSURE GRADIENT RESULTING IN NORTHEAST
TO EAST WINDS IN THE LOWER TEENS WITH GUSTS IN THE UPPER TEENS.
EXPECT THESE WINDS TO EASE ONCE AGAIN AROUND SUNSET. THE HIGH WILL
SLOWLY DRIFT EAST TOMORROW AND WEAKEN SOME WHILE THE LOW CONTINUES
ON ITS EASTWARD DRIFT AS WELL...RESULTING IN A WEAKER PRESSURE
GRADIENT AND LIGHTER WINDS. WINDS WILL STILL REMAIN NORTHEASTERLY
WITH SPEEDS AROUND 10 KT.
MID CLOUDS WILL CONTINUE TO STREAM NORTH OF THE LOW TO OUR SOUTH
AS UPPER LEVEL SHORTWAVE ENERGY APPROACHES FROM THE WEST TONIGHT
AND SUNDAY...THOUGH SOME LOWER CLOUDS WITH BASES AROUND 5000 FEET
TRY TO SNEAK INTO THE AREA AS WELL. AT THIS TIME KEEPING THE TAFS
DRY AS THE FORCING IS FAIRLY BENIGN AND THINK ANY COVERAGE WOULD
BE LOW. MOS GUIDANCE SUGGESTING SOME OUTLYING AREAS MAY SEE PATCHY
FOG...BUT FEEL THIS WILL BE LIMITED AS WELL WITH THE CLOUDS
DRIFTING NORTH. IF CLOUDS ARE LESS...KRFD AND KDPA MAY SEE MVFR
VISIBILITIES.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WIND SPEED AND DIRECTION.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 18Z...
SUNDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
MONDAY...VFR. CHANCE TSRA. NORTH TO NORTHEAST WINDS.
TUESDAY...VFR. SLIGHT CHANCE SHRA/TSRA EARLY. GUSTY NORTHWEST
WINDS.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR. SLIGHT CHANCE TSRA.
KMD
&&
.MARINE...
142 AM CDT
SPRAWLING HIGH PRESSURE ROUGHLY CENTERED NEAR GEORGIAN BAY EARLY
THIS MORNING WILL CONTINUE TO SLOWLY MOVE EASTWARD WHILE WEAK LOW
PRESSURE OVER THE LOWER OHIO VALLEY TRACKS NORTHEASTWARD. THE
WESTERN PORTION OF THE HIGH WILL BUILD SLIGHTLY SOUTHWARD THROUGH
THE DAY WHICH WILL COMBINE WITH THE OHIO VALLEY LOW TO PLACE A MORE
FOCUSED PRESSURE GRADIENT ACROSS SOUTHERN PORTIONS OF THE LAKE. THIS
WILL RESULT IN A MODEST INCREASE IN WIND SPEEDS THIS AFTERNOON ALONG
WITH A SHIFT TO MORE OF A NORTHEAST DIRECTION. NORTHERN SECTIONS OF
THE LAKE WILL SEE LIGHTER WINDS WHICH WILL TURN ONSHORE FOR THE
AFTERNOON. DO NOT SEE MUCH CHANGE IN CONDITIONS FOR SUNDAY WITH
STEADIER WINDS SOUTH AND LIGHTER ONSHORE FLOW NORTH. THE OVERALL
PATTERN WILL BEGIN TO EVOLVE THOUGH AS ANOTHER LOW BEGINS TO DEVELOP
OVER THE SOUTHERN PLAINS AND MOVES NORTHEAST TO THE LOWER OHIO
VALLEY. FORECAST GUIDANCE DIFFERS QUITE A BIT ON WHERE THE LOW
TRACKS BUT IT DOES LOOK TO CONSOLIDATE AND STRENGTHEN AS IT MOVES
NORTHEAST INTO TUESDAY. THE PRESSURE GRADIENT MAY REMAIN RATHER WEAK
MONDAY DESPITE THE DEVELOPING LOW SO A LIGHT NORTHERLY FLOW LOOKS TO
PERSIST. HIGH PRESSURE WILL BE SPREADING SOUTH AND EAST INTO THE
PLAINS AND MISSISSIPPI RIVER VALLEY AS THE LOW DEEPENS BRINGING A
STRONGER PRESSURE GRADIENT AND INTENSIFYING NORTHERLY WINDS ACROSS
THE LAKE MONDAY NIGHT INTO TUESDAY. STILL PLENTY OF TIME FOR DETAILS
TO CHANGE BUT 20-25 KT SPEEDS LOOK PLAUSIBLE AT THIS POINT DURING
THE DAY TUESDAY. THIS WILL BRING BUILDING WAVES THANKS TO THE LONG
NORTH FETCH. RIDGING THEN SPREADS ACROSS THE LAKE PROBABLY BRINGING
CONDITIONS NOT UNLIKE THOSE WE ARE CURRENTLY SEEING WITH LIGHTER
WIND SPEEDS AND GENERALLY ONSHORE FLOW FROM MID TO LATE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1218 PM CDT Sat Aug 9 2014
.UPDATE...
ISSUED AT 927 AM CDT SAT AUG 9 2014
Pesky surface low located over the western tip of Kentucky this
morning. Scattered showers continue to drift northwest across our
forecast area as far as Petersburg. Latest HRRR continues this
into the afternoon, primarily over east central Illinois. Further
north, skies have cleared in the extreme northern CWA, although
RAP guidance suggests the cloud deck may surge a bit further north
again over the next few hours.
Have sent an update to tweak the rain chances today, and pull back
the thunder threat to the extreme southeast CWA. Also have lowered
highs a few degrees except in the far north, as the clouds should
be rather persistent through the day, and current temperatures are
only in the upper 60s to lower 70s under the cloud cover.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 325 AM CDT SAT AUG 9 2014
Surface low pressure remains centered near the southern tip of
Illinois this morning with scattered light showers wrapping around
the low into east central Illinois. Thin fog has developed from
around Jacksonville to Lawrenceville and points southward where
lightest winds and higher dew points are noted in surface
observations. The low will continue to move very slowly eastward
today. Weak lift and saturated conditions through today will allow
for additional isolated showers and afternoon thunderstorms in
east central and southeast Illinois before a shortwave ridge
brings enough subsidence this evening to end precipitation
overnight. Temperatures still look on track to peak out just over
80 degrees for most of central Illinois today, but any areas with
persistent cloud cover and shower activity may fall short.
Persistent northeast winds 5-10 mph will continue for the next day
as a result of the pressure gradient around the low to the south
of the area.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 325 AM CDT SAT AUG 9 2014
Little change on Sunday with weak low pressure about 1014 mb over
western KY/lower Ohio river valley and 1020 mb high pressure over
Lake Huron. Biggest difference with 00Z models occurs Sunday night
where GFS model is an outlier with MCS and associated heavy QPF of
2-4.5 inches of rain tracking east across central IL Sunday night
and did not follow this solution. Did increase slight chance of
showers and thunderstorms further north across central IL Sunday
afternoon with chance pops in far SE IL near Wabash river. Added
slight chance of showers and thunderstorms to SW areas Sunday
night. Models keep surface boundary south of IL Sunday and Sunday
night so think if MCS does develop it will be further south on
Sunday night. SPC has 5% risk of severe storms south of IL early
next week. Sunday and Monday appear to be the warmest days with
highs in the lower to middle 80s which is closer to normal for mid
August. Humid too with dew points in the upper 60s and lower 70s
and highest in southern counties.
00z forecast model suite continue to show a strong upper level
trof digging into the Great Lakes and Ohio river valley Monday and
Tuesday with a cold front moving SE through central/SE IL during
Monday with surface low pressure deepening NE into lower MI Monday
night. Cold front moves east into Ohio and eastern KY by Tuesday
afternoon. Best chances of showers and thunderstorms still appears
to be during the day Monday and have 30-50% pops then with highest
pops in southeast IL. Lingered a small chance of showers and
isolated thunderstorms Tue over eastern IL with best chances of
convection shifting east of IL with the cold front. Cooler highs
in the upper 70s and lower 80s Tue and a bit cooler on Wed.
Dry conditions expected Tue night through Thu evening as weak high
pressure 1021 mb over western Canadian Rockies settles over IL by
Wed evening. This will also bring less humid air into central/SE
IL with more comfortable dew points of 55-60F on Wed and Thu.
Upper level trof pulls away from Illinois late next week as
temperatures and humidity levels slowly rise, with surface high
pressure ridge drifting east of IL and getting return southerly flow
by end of next week. Disturbances in the WNW flow to track across
the Midwest late next week and return chances of showers and
thunderstorms especially over western and northern areas.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1216 PM CDT SAT AUG 9 2014
MVFR ceilings persisting at KSPI/KDEC with IFR conditions not too
far south. North edge of the MVFR conditions continues to be
suppressed a bit southward, and am expecting these two sites to
lift above 3000 feet over the next couple hours. After that, VFR
conditions expected to prevail the remainder of the forecast
period. Persistent east/northeast flow to continue into Sunday
morning due to slow moving low pressure over Kentucky. Threat for
convection expected to increase later in the day on Sunday. Have
added some VCSH at KDEC/KCMI late morning, but too much
uncertainty elsewhere to add at this time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...ONTON
LONG TERM...07
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1117 AM CDT SAT AUG 9 2014
.DISCUSSION...
406 AM CDT
QUIET AND SEASONABLE WEATHER IS EXPECTED TO PERSIST THROUGH THE
WEEKEND...FOLLOWED BY INCREASED SHRA AND TSRA CHANCES MONDAY INTO
TUESDAY...THEN ANOTHER DRY PERIOD FOR THE LATTER HALF OF THE WEEK.
WITH THE GULF RETURN FLOW MOSTLY SHUT OFF...LOW LEVEL MOISTURE WILL
BE FAIRLY LIMITED THROUGH THE PERIOD...INHIBITING THE EFFECTS OF
FAVORABLE SHORTWAVE ENERGY ALOFT. HOWEVER...MODELS ARE SUGGESTING
THE PRESENCE OF SEVERAL SUCH WAVES...SO THERE IS A POSSIBILITY THAT
ONE OF THESE COULD BE POTENT ENOUGH AND TAP INTO JUST ENOUGH
MOISTURE TO TRIGGER AN ISOLATED BUT UNEXPECTED SHOWER OR
THUNDERSTORM WHEN MOST OF THE AREA REMAINS DRY.
A SURFACE LOW PASSING SOUTH OF THE AREA BRINGS THE BEST CHANCES OF
TSRA/SHRA MONDAY INTO MONDAY NIGHT. AGAIN...DUE TO LIMITED MOISTURE
IN THE EASTERLY FLOW AROUND THE NORTH SIDE OF THIS FEATURE...THERE
IS A QUESTION OF HOW FAR THE PRECIP SHIELD WILL SPREAD. THE CENTER
OF THE LOW ALSO COMES CLOSEST TO THE LOCAL AREA AT THE LEAST
FAVORABLE DIURNAL TIME...SUNDAY NIGHT INTO EARLY MONDAY MORNING.
BY MONDAY NIGHT INTO TUESDAY THE SURFACE LOW MOVES AWAY FROM THE
AREA...WRAPPING UP AND DEEPENING OVER THE OHIO VALLEY. THIS WILL
INCREASE THE CYCLONIC GRADIENT LOCALLY...TURN WINDS
NORTHWEST...LIKELY SUPPORT EXTENSIVE CLOUD COVER AND EVEN A FEW
SHOWERS...AND MAKE TUESDAY THE COOLEST AND BREEZIEST DAY OF THE
COMING WEEK.
AN APPROACHING RIDGE BEHIND THE DEPARTING LOW WILL AGAIN SUPPORT
CLEARING SKIES...LOWER PRECIP CHANCES...AND SLIGHTLY MODERATING
TEMPERATURES FOR WEDNESDAY AND THURSDAY.
FOR THURSDAY NIGHT AND FRIDAY...MODELS ARE SHOWING SOME DISAGREEMENT
IN HOW QUICKLY THE RIDGE BREAKS DOWN AND SLIDES AWAY TO THE EAST.
THERE IS A POSSIBILITY OF CONVECTIVE DEVELOPMENT DURING THIS PERIOD
ALONG A WARM FRONTAL FEATURE AHEAD OF THE NEXT APPROACHING LOW
PRESSURE SYSTEM...BUT FOR NOW HAVE ELECTED TO DOWNPLAY THE TSRA
CHANCES UNTIL IT BECOMES MORE CLEAR HOW QUICKLY THE RIDGE WILL
ACTUALLY DEPART.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST TO NORTHEAST WINDS 10-12 KT THROUGH TODAY. SPEEDS DIMINISHING
BELOW 10 KT AROUND SUNSET THIS EVENING.
KMD
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE SPREAD ACROSS THE UPPER GREAT LAKES WILL CONTINUE TO
SLOWLY MOVE EASTWARD THROUGH THE WEEKEND. LIGHT BUT STEADY EAST TO
NORTHEAST WINDS WILL CONTINUE OVERNIGHT WITH SPEEDS MODESTLY
INCREASING LATE THIS MORNING. THE BEST PRESSURE GRADIENT WILL
REMAIN DRAPED ACROSS THE CHICAGO AREA AND NORTHWEST INDIANA SO
SOME GUSTINESS IS LIKELY BUT SPEEDS SHOULD BE A LITTLE LOWER THAN
FRIDAY. LAKE INFLUENCES WILL TAKE OVER TURNING GYY NORTHEAST
AROUND MIDDAY AND ORD AND MDW LATER IN THE AFTERNOON. SPEEDS WILL
DIMINISH WITH SUNSET WITH A NORTHEASTERLY DIRECTION CONTINUING.
VFR WILL CONTINUE WITH INTERMITTENT HIGHER COVERAGE OF MID AND
HIGH CLOUDS. SOME LOWER VFR CLOUDS SPREAD IN FROM THE SOUTH AS A
MYRIAD OF WEAK SHORTWAVES ENCROACH ON THE REGION.
MDB/KMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH IN SPEEDS ABOVE 10 KT TODAY...MEDIUM IN TIMING AND ON GUST SPEED.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. SLIGHT CHANCE TSRA LATE.
MONDAY...VFR. CHANCE TSRA. NORTH TO NORTHEAST WINDS.
TUESDAY...VFR. SLIGHT CHANCE SHRA/TSRA EARLY. GUSTY NORTHWEST
WINDS.
WEDNESDAY...VFR.
THURSDAY...VFR. SLIGHT CHANCE TSRA LATE.
FRIDAY...VFR. SLIGHT CHANCE TSRA.
KMD
&&
.MARINE...
142 AM CDT
SPRAWLING HIGH PRESSURE ROUGHLY CENTERED NEAR GEORGIAN BAY EARLY
THIS MORNING WILL CONTINUE TO SLOWLY MOVE EASTWARD WHILE WEAK LOW
PRESSURE OVER THE LOWER OHIO VALLEY TRACKS NORTHEASTWARD. THE
WESTERN PORTION OF THE HIGH WILL BUILD SLIGHTLY SOUTHWARD THROUGH
THE DAY WHICH WILL COMBINE WITH THE OHIO VALLEY LOW TO PLACE A MORE
FOCUSED PRESSURE GRADIENT ACROSS SOUTHERN PORTIONS OF THE LAKE. THIS
WILL RESULT IN A MODEST INCREASE IN WIND SPEEDS THIS AFTERNOON ALONG
WITH A SHIFT TO MORE OF A NORTHEAST DIRECTION. NORTHERN SECTIONS OF
THE LAKE WILL SEE LIGHTER WINDS WHICH WILL TURN ONSHORE FOR THE
AFTERNOON. DO NOT SEE MUCH CHANGE IN CONDITIONS FOR SUNDAY WITH
STEADIER WINDS SOUTH AND LIGHTER ONSHORE FLOW NORTH. THE OVERALL
PATTERN WILL BEGIN TO EVOLVE THOUGH AS ANOTHER LOW BEGINS TO DEVELOP
OVER THE SOUTHERN PLAINS AND MOVES NORTHEAST TO THE LOWER OHIO
VALLEY. FORECAST GUIDANCE DIFFERS QUITE A BIT ON WHERE THE LOW
TRACKS BUT IT DOES LOOK TO CONSOLIDATE AND STRENGTHEN AS IT MOVES
NORTHEAST INTO TUESDAY. THE PRESSURE GRADIENT MAY REMAIN RATHER WEAK
MONDAY DESPITE THE DEVELOPING LOW SO A LIGHT NORTHERLY FLOW LOOKS TO
PERSIST. HIGH PRESSURE WILL BE SPREADING SOUTH AND EAST INTO THE
PLAINS AND MISSISSIPPI RIVER VALLEY AS THE LOW DEEPENS BRINGING A
STRONGER PRESSURE GRADIENT AND INTENSIFYING NORTHERLY WINDS ACROSS
THE LAKE MONDAY NIGHT INTO TUESDAY. STILL PLENTY OF TIME FOR DETAILS
TO CHANGE BUT 20-25 KT SPEEDS LOOK PLAUSIBLE AT THIS POINT DURING
THE DAY TUESDAY. THIS WILL BRING BUILDING WAVES THANKS TO THE LONG
NORTH FETCH. RIDGING THEN SPREADS ACROSS THE LAKE PROBABLY BRINGING
CONDITIONS NOT UNLIKE THOSE WE ARE CURRENTLY SEEING WITH LIGHTER
WIND SPEEDS AND GENERALLY ONSHORE FLOW FROM MID TO LATE WEEK.
MDB
&&
.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
NATIONAL WEATHER SERVICE LINCOLN IL
927 AM CDT Sat Aug 9 2014
.UPDATE...
ISSUED AT 927 AM CDT SAT AUG 9 2014
Pesky surface low located over the western tip of Kentucky this
morning. Scattered showers continue to drift northwest across our
forecast area as far as Petersburg. Latest HRRR continues this
into the afternoon, primarily over east central Illinois. Further
north, skies have cleared in the extreme northern CWA, although
RAP guidance suggests the cloud deck may surge a bit further north
again over the next few hours.
Have sent an update to tweak the rain chances today, and pull back
the thunder threat to the extreme southeast CWA. Also have lowered
highs a few degrees except in the far north, as the clouds should
be rather persistent through the day, and current temperatures are
only in the upper 60s to lower 70s under the cloud cover.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 325 AM CDT SAT AUG 9 2014
Surface low pressure remains centered near the southern tip of
Illinois this morning with scattered light showers wrapping around
the low into east central Illinois. Thin fog has developed from
around Jacksonville to Lawrenceville and points southward where
lightest winds and higher dew points are noted in surface
observations. The low will continue to move very slowly eastward
today. Weak lift and saturated conditions through today will allow
for additional isolated showers and afternoon thunderstorms in
east central and southeast Illinois before a shortwave ridge
brings enough subsidence this evening to end precipitation
overnight. Temperatures still look on track to peak out just over
80 degrees for most of central Illinois today, but any areas with
persistent cloud cover and shower activity may fall short.
Persistent northeast winds 5-10 mph will continue for the next day
as a result of the pressure gradient around the low to the south
of the area.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 325 AM CDT SAT AUG 9 2014
Little change on Sunday with weak low pressure about 1014 mb over
western KY/lower Ohio river valley and 1020 mb high pressure over
Lake Huron. Biggest difference with 00Z models occurs Sunday night
where GFS model is an outlier with MCS and associated heavy QPF of
2-4.5 inches of rain tracking east across central IL Sunday night
and did not follow this solution. Did increase slight chance of
showers and thunderstorms further north across central IL Sunday
afternoon with chance pops in far SE IL near Wabash river. Added
slight chance of showers and thunderstorms to SW areas Sunday
night. Models keep surface boundary south of IL Sunday and Sunday
night so think if MCS does develop it will be further south on
Sunday night. SPC has 5% risk of severe storms south of IL early
next week. Sunday and Monday appear to be the warmest days with
highs in the lower to middle 80s which is closer to normal for mid
August. Humid too with dew points in the upper 60s and lower 70s
and highest in southern counties.
00z forecast model suite continue to show a strong upper level
trof digging into the Great Lakes and Ohio river valley Monday and
Tuesday with a cold front moving SE through central/SE IL during
Monday with surface low pressure deepening NE into lower MI Monday
night. Cold front moves east into Ohio and eastern KY by Tuesday
afternoon. Best chances of showers and thunderstorms still appears
to be during the day Monday and have 30-50% pops then with highest
pops in southeast IL. Lingered a small chance of showers and
isolated thunderstorms Tue over eastern IL with best chances of
convection shifting east of IL with the cold front. Cooler highs
in the upper 70s and lower 80s Tue and a bit cooler on Wed.
Dry conditions expected Tue night through Thu evening as weak high
pressure 1021 mb over western Canadian Rockies settles over IL by
Wed evening. This will also bring less humid air into central/SE
IL with more comfortable dew points of 55-60F on Wed and Thu.
Upper level trof pulls away from Illinois late next week as
temperatures and humidity levels slowly rise, with surface high
pressure ridge drifting east of IL and getting return southerly flow
by end of next week. Disturbances in the WNW flow to track across
the Midwest late next week and return chances of showers and
thunderstorms especially over western and northern areas.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 630 AM CDT SAT AUG 9 2014
A mix of IFR/MVFR visibilities in light fog from around KIJX-KLWV
southward through central IL this morning, along with areas of
MVFR cigs. To the north, primarily VFR conditions are in place
with ceilings generally BKN040-060. Isold -shra in east central
IL due to saturated conditions and weak lift associated with a
low to the south of IL. For today, expecting improvements in
visibilities as well as increasing ceiling heights with daytime
heating. A few -SHRA/TSRA in east central/southeast IL could bring
briefly MVFR cigs/vsbys but otherwise VFR conditions. After 02Z,
shower activity ending but sky cover SCT-BKN040-050 continuing.
Winds NE5-10 kts through the 24 hour TAF forecast period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...ONTON
LONG TERM...07
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS WICHITA KS
323 PM CDT SAT AUG 9 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM CDT SAT AUG 9 2014
TON-SUN: MESOSCALE AGAIN COMPLICATING WHEN AND WHERE CONVECTION WILL
REDEVELOP THIS EVENING. BOUNDARY THAT LINGERS FROM CONVECTION THAT
MOVED INTO AND DISSIPATED ACROSS NORTH CENTRAL KANSAS
OVERNIGHT...APPEARS TO BE A POSSIBLE FOCUS FOR LATE AFTERNOON AND
EARLY EVENING CONVECTION. RUC HAS BEEN CONSISTENT IN DEVELOPING
WEAK...DIURNALLY DRIVEN CONVECTION FROM KEMP TO KCNK BETWEEN 22-23
UTC AND ADVECTING IT WEST SOUTHWEST INTO CENTRAL KANSAS. AT
PRESENT...UNSURE HOW THIS CONVECTION WILL INTERPLAY WITH
CONVECTION THAT SYNOPTIC/MESO MODELS BEGIN TO DEVELOP ALONG WEAK
SYNOPTIC BOUNDARY ACROSS WESTERN KANSAS DURING THE EVENING
HOURS...DUE TO INCREASING SYNOPTIC SCALE FORCING. A LARGE VORTEX
WILL MOVE ACROSS CENTRAL CANADA DURING THE NEXT 48 HOURS. LARGE
SCALE LIFT ACROSS KANSAS WILL INCREASE THIS EVENING IN RESPONSE TO
COMPACT SHORT WAVE THAT SKIRTS THE SOUTHERN PERIPHERY OF LARGE
VORTEX...AND JET STREAK MOVING NORTHEAST OUT OF NEW MEXICO AND
ACROSS KANSAS. OPERATIONAL SYNOPTIC MESOSCALE MODELS ARE SHOWING
QUITE A BIT OF VARIANCE IN TIMING AND COVERAGE OF OVERNIGHT
STORMS...FOR TIME BEING DECIDED TO USE SREF/SSEO AS GUIDE FOR
TIMING AND COVERAGE...WHICH BOTH ACCOUNT FOR SPREAD OF SOLUTIONS.
MESOSCALE FORCING WILL DICTATE PARTICULARS OF CONVECTIONS
TRACK...HOWEVER EXPECT ACTIVITY TO BE SUSTAINED THROUGH MOST OF
THE DAY SUNDAY DUE TO SLOW MOVEMENT OF LARGE SCALE VORTEX MOVING
ACROSS CENTRAL CANADA. AS BROADSCALE SUBSIDENCE OVERSPREADS REGION
SUNDAY EVENING...EXPECT BULK OF THE ACTIVITY TO DISSIPATE OR MOVE
EAST OF CWA BY 00 UTC ON MONDAY. TEMPERATURES TONIGHT AND SUNDAY
WILL BE DEPENDENT ON PRECIPITATION...WITH GUIDANCE LOOKING
REASONABLE.
MON-TUES: ANOTHER PERIOD OF DRY AND COOLER THAN NORMAL CONDITIONS.
AS UPPER VORTEX MOVES INTO EASTERN CANADA...WEAK RIDGING THAT HAS
BEEN LINGER OVER PLAINS RETROGRADES WEST. THIS WILL ALLOW COOLER
AIRMASS TO OVERSPREAD AREA...WITH HIGH AND LOW TEMPERATURES
AVERAGING 5 TO 10 DEGREES BELOW NORMAL FOR EARLY AUGUST.
SF
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 322 PM CDT SAT AUG 9 2014
COOLER THAN NORMAL AND DRY CONDITIONS WILL LINGER THROUGH
WEDNESDAY...BUT RETURN TO MORE TYPICAL AUGUST WEATHER RETURNS BY
LATE IN THE WEEK. AS EASTERN CANADA/U.S. VORTEX MOVES INTO THE
MARITIME REGION...UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS. BY LATE IN THE WEEK...EXPECT TEMPERATURES TO REBOUND
CLOSER TO NORMAL. KANSAS/CWA WILL REMAIN ON CYCLONIC SHEAR
SIDE...SETTING THE STAGE FOR POSSIBLE NOCTURNAL MCS ACTIVITY.
GEFS/OPERATIONAL MED-RANGE MODELS HIGHLIGHTING THE BEST CHANCES
FOR CONVECTION TO OCCUR THURSDAY AND FRIDAY NIGHT.
SF
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1218 PM CDT SAT AUG 9 2014
ANOTHER TOUGH CALL ON THUNDERSTORM FORECAST. ONCE AGAIN...CHANCE
THAT CONVECTIVE TEMPERATURES WILL BE REACHED THIS AFTERNOON...BUT
AT THE MOMENT...NO REAL CLEAR CUT SURFACE BOUNDARY TO FOCUS
CONVERGENCE. WILL LEAVE OUT THROUGHOUT THE AFTERNOON...GIVEN LOW
CONFIDENCE IN TIMING/LOCATION. DOES APPEAR THAT STORMS SHOULD
HAVE A BIT MORE UPPER SUPPORT TONIGHT AS UPPER WAVE MOVE THROUGH.
WILL INCLUDE VCTS AT ALL SITES OVERNIGHT...BUT GIVEN ANTICIPATED
SHORT DURATION AT ANY SITE...AND TIMING CHALLENGES THIS FAR OUT...
OPTED TO GO LONG PERIOD OF VCTS AND UPDATE WHEN TIMING BECOMES
CLEARER. PERIOD OF MVFR AND BRIEF PERIOD OF IFR CONDITIONS ARE
LIKELY WITH STORMS. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 71 89 68 87 / 50 30 20 10
HUTCHINSON 69 88 67 87 / 60 20 20 10
NEWTON 69 87 67 86 / 60 30 20 10
ELDORADO 69 89 67 86 / 50 40 20 10
WINFIELD-KWLD 72 90 69 87 / 50 40 30 10
RUSSELL 67 85 65 85 / 70 20 10 10
GREAT BEND 67 86 66 85 / 70 20 10 10
SALINA 69 87 66 87 / 70 30 20 10
MCPHERSON 69 87 67 87 / 60 30 20 10
COFFEYVILLE 73 91 69 88 / 50 50 40 10
CHANUTE 71 88 68 86 / 50 50 40 10
IOLA 70 87 68 85 / 60 50 40 10
PARSONS-KPPF 72 90 69 87 / 50 50 40 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1252 PM MDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 927 AM MDT SAT AUG 9 2014
THE DENSE FOG ADVISORY HAS BEEN CANCELED. METARS IN THE ADVISORY
AREA SHOW VISIBILITIES ABOVE ADVISORY CRITERIA. GRIDS AND ZONES
HAVE BEEN UPDATED.
UPDATE ISSUED AT 754 AM MDT SAT AUG 9 2014
UPDATED GRIDS AND ZONES TO INCREASE AREAL EXTENT AND DURATION OF
MORNING THUNDERSTORMS OVER EASTERN COLORADO INTO NORTHWEST KANSAS.
CURRENT RADAR SHOWING A FEW THUNDERSTORMS MOVING INTO CHEYENNE
COUNTY COLORADO.
UPDATE ISSUED AT 550 AM MDT SAT AUG 9 2014
ISSUED DENSE FOG ADVISORY WITH 1/4SM ALREADY FROM KIT CARSON
COUNTY TO SHERMAN COUNTY. I USED SATELLITE FOG PRODUCT (WHILE
PARTIALLY OBSCURED BY HIGH CLOUDS)...AND 06Z NAM FOR COVERAGE OF
DENSE FOG. HRRR/RAP DO INDICATE A SMALL AREA OF FOG IN THE
WEST...HOWEVER LOCATION AND COVERAGE ARE OFF FROM WHAT IS
CURRENTLY BEING REPORTED/OBSERVED.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 1245 PM MDT SAT AUG 9 2014
ANY STORMS MIGRATING EAST FROM THE FRONT RANGE/PALMER DIVIDE WILL
QUICKLY DISSIPATE SUNDAY EVENING WITH LOSS OF DAYTIME HEATING AND
QUICKLY DIMINISHING INSTABILITY. STRONG UPPER RIDGE WILL BUILD
INTO THE FOUR CORNERS ON MONDAY AND SLOWLY MOVE EAST ACROSS THE
ROCKIES THROUGH MID WEEK. INSTABILITY WILL BE LIMITED MAINLY TO
EASTERN COLORADO THIS PERIOD AND WITH LITTLE TO NO FORCING ALOFT
ONLY ISOLATED/WIDELY SCATTERED DIURNAL STORMS ARE EXPECTED...AGAIN
CONFINED MAINLY TO EASTERN COLORADO. THE RIDGE BEGINS TO BREAK
DOWN LATE WEEK AND WITH DISTURBANCE COMING OVER THE RIDGE OUT
OF THE ROCKIES THUNDERSTORM CHANCES WILL BE INCREASING.
TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1133 AM MDT SAT AUG 9 2014
VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24
HOURS. HOWEVER, THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS AT
BOTH SITES BY MID AFTERNOON WITH CLEARING TOWARD MIDNIGHT. EARLY
SUNDAY MORNING THE FORECAST SOUNDING FOR KMCK INDICATES THE
POSSIBILITY OF STRATUS AND FOG AT KMCK. VISIBILITY AND CIGS AT
KMCK MAY LOWER TO MVFR FOR A FEW HOURS SUNDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...024
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1138 AM MDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 927 AM MDT SAT AUG 9 2014
THE DENSE FOG ADVISORY HAS BEEN CANCELLED. METARS IN THE ADVISORY
AREA SHOW VISIBILITIES ABOVE ADVISORY CRITERIA. GRIDS AND ZONES
HAVE BEEN UPDATED.
UPDATE ISSUED AT 754 AM MDT SAT AUG 9 2014
UPDATED GRIDS AND ZONES TO INCREASE AREAL EXTENT AND DURATION OF
MORNING THUNDERSTORMS OVER EASTERN COLORADO INTO NORTHWEST KANSAS.
CURRENT RADAR SHOWING A FEW THUNDERSTORMS MOVING INTO CHEYENNE
COUNTY COLORADO.
UPDATE ISSUED AT 550 AM MDT SAT AUG 9 2014
ISSUED DENSE FOG ADVISORY WITH 1/4SM ALREADY FROM KIT CARSON
COUNTY TO SHERMAN COUNTY. I USED SATELLITE FOG PRODUCT (WHILE
PARTIALLY OBSCURED BY HIGH CLOUDS)...AND 06Z NAM FOR COVERAGE OF
DENSE FOG. HRRR/RAP DO INDICATE A SMALL AREA OF FOG IN THE
WEST...HOWEVER LOCATION AND COVERAGE ARE OFF FROM WHAT IS
CURRENTLY BEING REPORTED/OBSERVED.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1133 AM MDT SAT AUG 9 2014
VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24
HOURS. HOWEVER, THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS AT
BOTH SITES BY MID AFTERNOON WITH CLEARING TOWARD MIDNIGHT. EARLY
SUNDAY MORNING THE FORECAST SOUNDING FOR KMCK INDICATES THE
POSSIBILITY OF STRATUS AND FOG AT KMCK. VISIBILLITY AND CIGS AT
KMCK MAY LOWER TO MVFR FOR A FEW HOURS SUNDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...JRM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
929 AM MDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 927 AM MDT SAT AUG 9 2014
THE DENSE FOG ADVISORY HAS BEEN CANCELLED. METARS IN THE ADVISORY
AREA SHOW VISIBILITIES ABOVE ADVISORY CRITERIA. GRIDS AND ZONES
HAVE BEEN UPDATED.
UPDATE ISSUED AT 754 AM MDT SAT AUG 9 2014
UPDATED GRIDS AND ZONES TO INCREASE AREAL EXTENT AND DURATION OF
MORNING THUNDERSTORMS OVER EASTERN COLORADO INTO NORTHWEST KANSAS.
CURRENT RADAR SHOWING A FEW THUNDERSTORMS MOVING INTO CHEYENNE
COUNTY COLORADO.
UPDATE ISSUED AT 550 AM MDT SAT AUG 9 2014
ISSUED DENSE FOG ADVISORY WITH 1/4SM ALREADY FROM KIT CARSON
COUNTY TO SHERMAN COUNTY. I USED SATELLITE FOG PRODUCT (WHILE
PARTIALLY OBSCURED BY HIGH CLOUDS)...AND 06Z NAM FOR COVERAGE OF
DENSE FOG. HRRR/RAP DO INDICATE A SMALL AREA OF FOG IN THE
WEST...HOWEVER LOCATION AND COVERAGE ARE OFF FROM WHAT IS
CURRENTLY BEING REPORTED/OBSERVED.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM MDT SAT AUG 9 2014
DENSE FOG HAS DEVELOPED AT THE KGLD TERMINAL THIS MORNING...WHICH
IS WELL HANDLED BY LATEST SHORT RANGE GUIDANCE. FOG HAS YET TO
DEVELOP AT KMCK...HOWEVER WITH CLEARING SKIES SATURATION SHOULD
BEGIN TO OCCUR...THOUGH GUIDANCE DOES KEEP EDGE OF DENSE FOG JUST
WEST OF KMCK TERMINAL. HAVE INTRODUCED VLIFR TO KGLD TAFS THIS
MORNING AND IFR TO KMCK WITH IMPROVEMENT EXPECTED BY MID MORNING.
AS FRONT MOVES SOUTH OVER REGION TODAY THUNDERSTORMS SHOULD
DEVELOP FROM THE WEST AND NORTH. STRONG WINDS WILL BE POSSIBLE. I
LEFT VCTS MENTION IN PLACE FOR NOW FOR THE AFTERNOON/EVENING
PERIODS...AND WE WILL NEED TO FINE TUNE TIMING. STRONG WINDS COULD
BE POSSIBLE WITH THIS ACTIVITY...ESPECIALLY AT KMCK. ANOTHER ROUND
OF STRATUS/FOG MAY DEVELOP BY EARLY SUNDAY MORNING...HOWEVER
CONFIDENCE WAS TOO LOW YET TO LOWER VIS/CIG BELOW VFR YET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
756 AM MDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 754 AM MDT SAT AUG 9 2014
UPDATED GRIDS AND ZONES TO INCREASE AREAL EXTENT AND DURATION OF
MORNING THUNDERSTORMS OVER EASTERN COLORADO INTO NORTHWEST KANSAS.
CURRENT RADAR SHOWING A FEW THUNDERSTORMS MOVING INTO CHEYENNE
COUNTY COLORADO.
UPDATE ISSUED AT 550 AM MDT SAT AUG 9 2014
ISSUED DENSE FOG ADVISORY WITH 1/4SM ALREADY FROM KIT CARSON
COUNTY TO SHERMAN COUNTY. I USED SATELLITE FOG PRODUCT (WHILE
PARTIALLY OBSCURED BY HIGH CLOUDS)...AND 06Z NAM FOR COVERAGE OF
DENSE FOG. HRRR/RAP DO INDICATE A SMALL AREA OF FOG IN THE
WEST...HOWEVER LOCATION AND COVERAGE ARE OFF FROM WHAT IS
CURRENTLY BEING REPORTED/OBSERVED.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM MDT SAT AUG 9 2014
DENSE FOG HAS DEVELOPED AT THE KGLD TERMINAL THIS MORNING...WHICH
IS WELL HANDLED BY LATEST SHORT RANGE GUIDANCE. FOG HAS YET TO
DEVELOP AT KMCK...HOWEVER WITH CLEARING SKIES SATURATION SHOULD
BEGIN TO OCCUR...THOUGH GUIDANCE DOES KEEP EDGE OF DENSE FOG JUST
WEST OF KMCK TERMINAL. HAVE INTRODUCED VLIFR TO KGLD TAFS THIS
MORNING AND IFR TO KMCK WITH IMPROVEMENT EXPECTED BY MID MORNING.
AS FRONT MOVES SOUTH OVER REGION TODAY THUNDERSTORMS SHOULD
DEVELOP FROM THE WEST AND NORTH. STRONG WINDS WILL BE POSSIBLE. I
LEFT VCTS MENTION IN PLACE FOR NOW FOR THE AFTERNOON/EVENING
PERIODS...AND WE WILL NEED TO FINE TUNE TIMING. STRONG WINDS COULD
BE POSSIBLE WITH THIS ACTIVITY...ESPECIALLY AT KMCK. ANOTHER ROUND
OF STRATUS/FOG MAY DEVELOP BY EARLY SUNDAY MORNING...HOWEVER
CONFIDENCE WAS TOO LOW YET TO LOWER VIS/CIG BELOW VFR YET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY UNTIL 10 AM MDT /11 AM CDT/ THIS MORNING FOR
KSZ001-002-013>015-027>029-041-042.
CO...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR COZ090>092.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
550 AM MDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 550 AM MDT SAT AUG 9 2014
ISSUED DENSE FOG ADVISORY WITH 1/4SM ALREADY FROM KIT CARSON
COUNTY TO SHERMAN COUNTY. I USED SATELLITE FOG PRODUCT (WHILE
PARTIALLY OBSCURED BY HIGH CLOUDS)...AND 06Z NAM FOR COVERAGE OF
DENSE FOG. HRRR/RAP DO INDICATE A SMALL AREA OF FOG IN THE
WEST...HOWEVER LOCATION AND COVERAGE ARE OFF FROM WHAT IS
CURRENTLY BEING REPORTED/OBSERVED.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM MDT SAT AUG 9 2014
DENSE FOG HAS DEVELOPED AT THE KGLD TERMINAL THIS MORNING...WHICH
IS WELL HANDLED BY LATEST SHORT RANGE GUIDANCE. FOG HAS YET TO
DEVELOP AT KMCK...HOWEVER WITH CLEARING SKIES SATURATION SHOULD
BEGIN TO OCCUR...THOUGH GUIDANCE DOES KEEP EDGE OF DENSE FOG JUST
WEST OF KMCK TERMINAL. HAVE INTRODUCED VLIFR TO KGLD TAFS THIS
MORNING AND IFR TO KMCK WITH IMPROVEMENT EXPECTED BY MID MORNING.
AS FRONT MOVES SOUTH OVER REGION TODAY THUNDERSTORMS SHOULD
DEVELOP FROM THE WEST AND NORTH. STRONG WINDS WILL BE POSSIBLE. I
LEFT VCTS MENTION IN PLACE FOR NOW FOR THE AFTERNOON/EVENING
PERIODS...AND WE WILL NEED TO FINE TUNE TIMING. STRONG WINDS COULD
BE POSSIBLE WITH THIS ACTIVITY...ESPECIALLY AT KMCK. ANOTHER ROUND
OF STRATUS/FOG MAY DEVELOP BY EARLY SUNDAY MORNING...HOWEVER
CONFIDENCE WAS TOO LOW YET TO LOWER VIS/CIG BELOW VFR YET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY UNTIL 10 AM MDT /11 AM CDT/ THIS MORNING FOR
KSZ001-002-013>015-027>029-041-042.
CO...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR COZ090>092.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
525 AM MDT SAT AUG 9 2014
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM MDT SAT AUG 9 2014
DENSE FOG HAS DEVELOPED AT THE KGLD TERMINAL THIS MORNING...WHICH
IS WELL HANDLED BY LATEST SHORT RANGE GUIDANCE. FOG HAS YET TO
DEVELOP AT KMCK...HOWEVER WITH CLEARING SKIES SATURATION SHOULD
BEGIN TO OCCUR...THOUGH GUIDANCE DOES KEEP EDGE OF DENSE FOG JUST
WEST OF KMCK TERMINAL. HAVE INTRODUCED VLIFR TO KGLD TAFS THIS
MORNING AND IFR TO KMCK WITH IMPROVEMENT EXPECTED BY MID MORNING.
AS FRONT MOVES SOUTH OVER REGION TODAY THUNDERSTORMS SHOULD
DEVELOP FROM THE WEST AND NORTH. STRONG WINDS WILL BE POSSIBLE. I
LEFT VCTS MENTION IN PLACE FOR NOW FOR THE AFTERNOON/EVENING
PERIODS...AND WE WILL NEED TO FINE TUNE TIMING. STRONG WINDS COULD
BE POSSIBLE WITH THIS ACTIVITY...ESPECIALLY AT KMCK. ANOTHER ROUND
OF STRATUS/FOG MAY DEVELOP BY EARLY SUNDAY MORNING...HOWEVER
CONFIDENCE WAS TOO LOW YET TO LOWER VIS/CIG BELOW VFR YET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
235 AM MDT SAT AUG 9 2014
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 234 AM MDT SAT AUG 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A CLOSED LOW OVER SOUTH
DAKOTA WITH MID-UPPER LEVEL DRY LAYER ASSOCIATED WITH SUBSIDENCE ON
BACK SIDE OF THIS SHORTWAVE TROUGH OVER OUR CWA. AT THE SURFACE A
STATIONARY FRONT IS CURRENTLY IN PLACE ACROSS SW NEBRASKA EXTENDING
SOUTH ACROSS CENTRAL KANSAS. THUNDERSTORM ACTIVITY HAS SHIFTED EAST
OF THE CWA.
THIS MORNING...WITH SUBSIDENCE IN PLACE SHOWER/THUNDERSTORM ACTIVITY
SHOULD BE LIMITED TO LOCATIONS EAST OF THE CWA. MAIN CONCERN WILL BE
FOG POTENTIAL WITH SHORT RANGE GUIDANCE SHOWING FOG DEVELOPMENT IN
THE WEST AND EAST. TD VALUES REMAIN VERY HIGH ACROSS MUCH OF THE CWA
WITH VALUES IN THE 70S ACROSS THE SOUTHWEST. TD DEPRESSIONS ARE
ALREADY NEAR ZERO AT MANY LOCATIONS ACROSS THE SOUTHERN PART OF THE
CWA. I WENT AHEAD AND ADDED PATCHY FOG TO FORECAST...AND WILL
MONITOR FOR POTENTIAL DENSE FOG DEVELOPMENT.
THIS AFTERNOON-TONIGHT...A WEAK SHORTWAVE TROUGH CURRENTLY OVER THE
GREAT BASIN SHOULD MOVE ACROSS NE/KS LATE THIS AFTERNOON EVENING.
HIGHER TERRAIN IN COLORADO AND FRONTAL ZONE SHOULD ACT AS MAIN AREAS
FOR INITIATION. BETTER INSTABILITY/SHEER PROFILES LATER TODAY SHOULD
BE LIMITED TO FRONTAL ZONE IN OUR EAST...AND THIS IS WHERE THE MAIN
CONCERN FOR SEVERE THUNDERSTORMS WILL BE. THERE IS AT LEAST SOME
SIGNAL FROM GUIDANCE THAT THUNDERSTORM COVERAGE WILL INCREASE IN THE
EAST AS A COLD POOL DRIVEN CLUSTER/COMPLEX DEVELOPS AND TRANSITIONS
SOUTH AND EAST. STORM MOTIONS WILL BE RELATIVELY SLOW...WHICH
COMBINED WITH THE ANOMALOUSLY MOIST AIR MASS (PWATS AROUND
1.5")...HEAVY RAIN IS ALSO A POSSIBILITY. SHEER PROFILES WOULD FAVOR
MORE OF A STRONG WIND/LARGE HAIL THREATS.
SUNDAY-MONDAY NIGHT... QUASI-STATIONARY FRONT IS ALSO GOING TO
LINGER OVER OUR CWA...AND GUIDANCE HAS VERY LITTLE AGREEMENT ON
POSITION OF THIS FEATURE WHICH IMPACTS HIGH TEMPS AND PRECIP
POTENTIAL. OTHER THAN SOME WEAK VORTICITY ALOFT...THERE REALLY ISNT
MUCH IN THE WAY OF LARGER SCALE FORCING. MODEL CONSENSUS GENERALLY
HAS BACKED OFF ON PRECIP POTENTIAL OVER OUR CWA...WITH BETTER
CHANCES TIED TO HIGHER TERRAIN AND FRONTAL ZONE. I TRENDED POPS DOWN
FROM PREVIOUS FORECAST AND ADJUSTED TIMING TO DIURNALLY FAVORED
PERIODS WITH CINH HAS BEST CHANCE TO WEAKEN. I HAVE LOW CONFIDENCE
IN HIGH TEMPS AT THIS POINT DUE TO UNCERTAINTY WITH FRONTAL
POSITION...SO I USED CONSENSUS APPROACH WHICH ALLOWS FOR SOME
COOLING OF HIGHS SUNDAY AND MONDAY TO MID 80S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 234 AM MDT SAT AUG 9 2014
MEDIUM RANGE MODELS IN REASONABLE
AGREEMENT FOR THE FIRST PORTION OF THE FORECAST PERIOD WITH STRONG
RIDGING TAKING PLACE ACROSS THE PLAINS WITH LEE TROUGH GRADUALLY
DEVELOPING THROUGH THIS TIME. MODELS DIVERGE AS TO HOW QUICKLY
RIDGE FLATTENS AND ASSOCIATED FROPA SO STUCK CLOSE TO CONSENSUS
FIELDS WITH RESPECT TO TEMPS AND SENSIBLE WEATHER FOR LATTER HALF OF
PERIOD. WITH LEE TROUGH IN PLACE DID NUDGE MIN TEMPS UP A FEW
DEGREES BUT OVERALL FORECAST LOOKS TO BE IN GOOD SHAPE. WHILE SOME
QUESTIONS REMAIN ABOUT PRECIP CHANCES...CURRENT FORECAST SUPPORTED
BY GEFS SO DID NOT MAKE MAJOR CHANGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1116 PM MDT FRI AUG 8 2014
THUNDERSTORMS HAVE MOVED EAST OF THE AREA FOR THE NIGHT. VFR
CONDITIONS ARE EXPECTED THROUGH MOST OF THE REST OF THE PERIOD.
DURING THE EVENING HOURS ON SATURDAY...THUNDERSTORMS ARE EXPECTED
TO DEVELOP NEAR OR TO THE WEST OF BOTH SITES. AT THIS TIME CHOSE
TO HANDLE THIS WITH A VCTS. HOWEVER...IT DOES LOOK LIKE
THUNDERSTORMS WILL AFFECT BOTH SITES AND COULD CAUSE SUB VFR
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
839 PM CDT Sun Aug 10 2014
.UPDATE...
Issued at 837 PM CDT SUN AUG 10 2014
Best surface based moisture and instability remains clustered
across the western edge of the WFO PAH forecast area during the
last 2-3 hours. However, there is some evidence that theta-e
convergence at the low levels is working southeast toward the
confluence of the Mississippi and Ohio Rivers in advance of a weak
surface low centered near Oregon County Missouri at 8 pm CDT.
The current convection appears to be moving from surface based to
elevated in a weak shear environment. The RAP/HRRR guidance
suggests some redevelopment during the overnight hours near the
frontal axis near the upper end of the planetary boundary layer
stretching from Southeast Missouri into southern sections of West
Kentucky. Although tempting to remove any measurable PoPs
overnight, the RAP suggests another wave rotating southeast in the
upper trough through Missouri after midnight. Surface to 850 mb
lapse rates are marginal for convection, as well as low level
(0-3km) shear. At this time, backed off wider coverage of
PoPs/Weather, but did not eliminate at all near the antecedent
frontal boundary overnight. There still seems to be some
maintenance of the multi-cellular convection this evening, so will
leave a small PoP overnight. Given the cloud cover, patchy fog, and
proximity to the old frontal boundary, raised temperatures one to two
degrees into southern sections of West Kentucky,
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 115 PM CDT SUN AUG 10 2014
Area still convection free. However a wave moving across wcntrl MO
appears headed for the CWA. Convection with it not terribly
impressive. Accounted for it with some chance PoPs as it continues
east. Otherwise, some PVA seen in the models overnight, means
keeping chance PoPs going is warranted for showers, maybe a
rumble of thunder. Could see some fog development again tonight
given little change in surface-boundary layer conditions.
Chance PoPs will continue Monday, though will slowly shift east
with time into the afternoon and Monday night with associated weak
forcing. Inherited dry Tuesday and a consensus of the latest data
continues to support that notion for the most part. Dry, cooler
and less humid Tuesday night as high pressure continues to build in.
.LONG TERM...(Wednesday through Sunday)
Issued at 246 PM CDT SUN AUG 10 2014
High pressure over the middle Mississippi valley will keep the
region dry Wednesday into Thursday. Dry and cooler air will
remain in place with continued light north to northeast winds. As
the high moves east, winds will shift back to the south late
Thursday into Friday. Warmer air and increasing dew points can be
expected Friday and through the weekend with temperatures back to
seasonal normals over the weekend. Models are in disagreement and
overall inconsistent dealing with an upper level trof affecting
the PAH forecast area Friday and through the weekend. Models have
backed off precip chances for Friday, so removed any chances for
showers and thunderstorms. The latest ECMWF is much more
aggressive than its previous run and spreads significant precip
across our entire region Friday night into Saturday. The latest
GFS looks more like the much slower previous ECMWF run. Overall
believe chances will slowly increase through the weekend from west
to east, but due to timing uncertainties, kept pops in the chance
to slight chance categories for now.
&&
.AVIATION...
Issued at 626 PM CDT SUN AUG 10 2014
An upper-level storm system will sweep southeast through the area
Monday. This will push an ill-defined cold frontal boundary
through the region by 18Z. Scattered convection is advertised
throughout the area Monday, and there is some signal for a few
shra/tsra tonight, but that would most likely be near KCGI and
KPAH. Confidence in timing is too low to pinpoint in the TAFs at
this time.
Also have a low confidence in the ceiling and fog potential
tonight. The best signal is for IFR or lower ceilings at KPAH late
tonight into the morning, and for MVFR/IFR ceilings moving into
KEVV and KOWB after sunrise and lingering for much of the day.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...Smith
LONG TERM...RST
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
127 AM EDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 1105 PM EDT FRI AUG 8 2014
DID A QUICK UPDATE TO FINE TUNE THE POPS AND WX THROUGH THE REST OF
THE NIGHT. THIS ENTAILED MAINLY TAKING THEM DOWN IN THE NEAR TERM PER
THE HRRR AND ADJUSTING THE FOG WITH INCREASED CONCERNS FOR DENSE
PATCHES LATER IN THE NIGHT. ALSO MATCHED UP THE T/TD GRIDS WITH THE
LATEST OBS AND TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS WITH A NEW ZFP TO FOLLOW.
UPDATE ISSUED AT 825 PM EDT FRI AUG 8 2014
23Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE THROUGH THE MID
MISSISSIPPI VALLEY. A WARM FRONT EXTENDS FROM THIS TO CENTRAL
KENTUCKY WHERE IT IS HELPING TO SPAWN SHOWERS AND THUNDERSTORMS
THAT ARE DRIFTING EAST INTO THE JKL CWA. ACROSS EAST KENTUCKY TEMPS
AND DEW POINTS ARE HOLDING IN THE UPPER 60S AND LOWER 70S.
MEANWHILE...WINDS ARE GENERALLY LIGHT FROM THE EAST OUT HERE...AHEAD
OF THE SFC BOUNDARY. OUR VERY DAMP ENVIRONMENT WILL PERSIST THROUGH
THE NIGHT WITH OCCASIONAL SHOWERS AND THUNDERSTORMS. THE TRAINING OF
THESE CELLS WILL NEED TO BE WATCHED FOR A POTENTIAL OF EXCESSIVE
RAINS LEADING TO LOCALIZED FLASH FLOODING. SO FAR...MUCH OF THE AREA
HAS BEEN SPARED SUBSTANTIAL RAINS AMOUNTING TO MORE THAN A HALF AN
INCH. HOWEVER...THERE ARE A COUPLE OF PLACES...ONE EAST OF JACKSON
AND ANOTHER OVER WESTERN PARTS OF THE CUMBERLAND VALLEY...THAT WILL
NEED EXTRA SCRUTINY OVERNIGHT DUE TO AMOUNTS OF NEARLY 2 INCHES
FALLING EARLIER IN THE DAY. HAVE UPDATED THE GRIDS TO TIME THE
CURRENT ACTIVITY AND MELD IT INTO A GENERALLY WET FORECAST FOR THE
REST OF THE NIGHT...IN CONJUNCTION WITH THE LATEST HRRR AND NAM12.
ALSO FINE TUNED TEMPERATURES AND DEW POINTS INTO DAWN BASED ON THE
LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THE GRIDS HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS ALONG WITH THE ISSUANCE OF AN
UPDATED ZFP.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI AUG 8 2014
A FRONTAL SYSTEM WITH A VERY SLOWLY MOVING LOW PRESSURE SYSTEM IS OVER
SOUTHERN ILLINOIS. THIS LOW WILL CONTINUE MOVING SLOWLY TO THE
SOUTHEAST. BY TOMORROW EVENING THE LOW IS EXPECTED TO BE OVER
WESTERN KENTUCKY. BY SUNDAY EVENING THE LOW WILL DRIFT SOUTH AND WILL
BE OVER WESTERN TENNESSEE. THIS WILL RESULT IN EASTERN KENTUCKY TO BE
IN AN AREA OF OVERRUNNING AND ISENTROPIC LIFT THROUGH SATURDAY NIGHT.
AS A RESULT...EXPECT BANDS OF SHOWERS...SOMETIMES WITH AN EMBEDDED
THUNDERSTORM THROUGH THE END OF THE PERIOD. THERE ARE A COUPLE OF
AREAS THAT SAY AROUND AN INCH OF RAIN TODAY...HOWEVER THIS IS OVER
RELATIVELY SMALL AREAS. IF MORE HEAVY RAIN MOVES OVER THE SAME
AREAS EFFECTED EARLIER...THEN THERE IS A CHANCE FOR SOME LOCALIZED FLASH
FLOODING. THE BEST CHANCE FOR THUNDER WILL BE IN THE NEXT 2-4 HOURS
AS A THUNDERSTORM MOVES IN FROM CENTRAL KENTUCKY. EXPECT AREAS OF
DENSE VALLEY FOG TONIGHT DUE TO THE WIDESPREAD PRECIPITATION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 PM EDT FRI AUG 8 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SUNDAY WITH AN UPPER LEVEL
PATTERN IN TRANSITION TO A MORE MERIDIONAL PATTERN AS AN UPPER LEVEL
RIDGE OVER THE GREAT LAKES AND MID ATLANTIC STATES MOVES EASTWARD
AND WEAKENING AS IT MOVES INTO THE NEW ENGLAND STATES AND EVENTUALLY
EXITS INTO THE CANADIAN MARITIMES. MEANWHILE...THE RIDGE OVER THE
WESTERN CONUS CONTINUES TO BUILD AS A DEEPENING LONGWAVE TROUGH
FORMS OVER THE CENTRAL PLAINS AND SETS UP OVER THE EASTERN CONUS.
THIS COMBINATION FORMS A DEVELOPING STAGNANT PATTERN AS A BLOCKING
PATTERN SETS UP WITH A CLOSED LOW FORMING OVER THE GREAT LAKES AND
NEW ENGLAND REGION BY THE END OF THE EXTENDED. MODELS HAVE BEEN
TRENDING TO A MORE AMPLIFIED OR EVEN BLOCKING PATTERN TOWARD THE END
OF THE WORKWEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 127 AM EDT SAT AUG 9 2014
CONDITIONS WERE LARGELY IFR NORTH AND EAST OF KJKL AT TAF
ISSUANCE...AND VFR WITH SOME MVFR TO THE SOUTHWEST. AN OVERALL
DETERIORATION IS FORECAST OVERNIGHT...WITH GENERALLY IFR ACROSS THE
AREA BY DAWN. GRADUAL IMPROVEMENT SHOULD OCCUR ON SATURDAY...WITH
MAINLY MVFR BY MID DAY. HOWEVER...SHOWERS AND THUNDERSTORMS AREA
EXPECTED TO POP UP IN THE AFTERNOON...BRINGING DETERIORATING
CONDITIONS AT TIMES. HOWEVER...THE TIMING AND LOCATION OF THE
POTENTIAL IFR IS TOO UNCERTAIN TO INCLUDE IN TAFS. AS SHOWERS AND
STORMS DIE OUT ON SATURAY EVENING...VFR IS FORECAST TO RETURN...BUT
NOT A HIGH CONFIDENCE FORECAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
300 PM CDT SAT AUG 9 2014
.DISCUSSION...
LITTLE HAS CHANGED IN THE UPPER LEVEL PATTERN WITH WEAK UPPER LEVEL
RIDGE IN PLACE OVER THE AREA WITH THE HIGH REACHING FROM THE
SOUTHEAST GULF OF MEXICO TO ARIZONA. DAYTIME HEATING CONTINUES TO
EASILY OVERCOME ANY SUBSIDENCE IN PLACE AND ALLOWING FOR SCATTERED
SHOWERS AND THUNDERSTORMS ALTHOUGH INTENSITIES ARE SLIGHTLY WEAKER
IN GENERAL COMPARED TO YSTRDY. STORM MOTION HAS FALLEN OFF A BIT
WITH STORMS EXHIBITING LITTLE MOVEMENT. THE MAIN THREAT WITH THIS
ACTIVITY WILL BE CG LIGHTNING AND LOCALIZED HEAVY RAINFALL. CONVECTION
SHOULD DISSIPATE AROUND SUNSET WITH POSSIBLE A FEW SHOWERS OFFSHORE
OVERNIGHT. THE HRRR DOES INDICATE THAT MORE WIDESPREAD STORMS
CURRENTLY LOCATED NORTH OF THE CWA WILL MOVE INTO THE AREA LATE THIS
AFTERNOON BUT THE SLOW MOVEMENT SOUTHWARD AT THIS TIME SAYS
OTHERWISE. THIS DAILY TREND OF SHOWERS AND STORMS ALONG WITH
LOWER/MID 90 HIGHS WILL CONTINUE THROUGH THE WEEKEND AND EARLY NEXT
WEEK. RAIN CHANCES WILL REMAIN ABOUT THE SAME EACH DAY IN THE CHANCE
CATEGORY.
THE PATTERN WILL BEGIN TO CHANGE MOVING INTO THE MIDDLE OF NEXT
WEEK. AN UPPER LEVEL TROUGH WILL DIVE SOUTH OUT OF CANADA AND HEAD
TOWARDS THE SOUTHEASTERN CONUS WHILE RIDGE RETROGRADES BACK WEST. A
COLD FRONT ASSOCIATED WITH THIS FEATURE WILL MAKE ITS WAY DOWN TO
THE CWA IN AROUND MIDDAY TUESDAY. THE FRONT WILL BE STALLING RIGHT
OVER THE AREA AND LIKELY BE A FOCUS FOR STORM AREAL ENHANCEMENT FOR
A FEW DAYS. DOES NOT APPEAR SVR WX WILL BE AN ISSUE WITH WETBULB HT
14KFT AND ABOVE AS WELL AS VERY WEAK WIND FIELD IN PLACE.
MEFFER
&&
.AVIATION...
VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL AT THE TERMINALS
THROUGH THE TAF FORECAST PERIOD. ISOLATED CONVECTION THAT MAY IMPACT
THE TAF SITES...PRIMARILY DURING THIS AFTERNOON AFTERNOON AND EARLY
EVENING HOURS. A PERIOD OF LIGHT FOG COULD RESULT IN A PERIOD OF
RESTRICTED VISIBILITIES IN THE MVFR CATEGORY PRIOR TO AND AROUND
SUNRISE SUNDAY MORNING FROM KHUM AND KMCB. 18
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL PREVAIL ACROSS THE NORTH GULF OF
MEXICO INTO NEXT WEEK. A COLD FRONT WILL APPROACH AND LIKELY STALL
NORTH OF THE CENTRAL GULF COAST BY THE MIDDLE OF THE UPCOMING WEEK.
WINDS WILL GENERALLY BE FROM THE SOUTH TO THE WEST AT 10 KNOTS OR
LESS WITH SEAS 2 FEET OR LESS. 18
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 73 93 74 92 / 20 50 20 50
BTR 76 94 74 93 / 20 50 20 40
ASD 75 93 75 92 / 20 50 20 40
MSY 77 92 78 91 / 20 50 20 40
GPT 78 91 78 92 / 20 50 20 40
PQL 74 91 73 91 / 20 50 30 40
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
700 PM CDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
AN UNSETTLED WEATHER PATTERN EXISTS ACROSS CENTRAL NOAM...WITH A
STRONG WAVE ENTERING WRN HUDSON BAY. THE TROUGH ASSOCIATED WITH THIS
UPPER LOW EXTENDS SOUTH INTO NRN MO. WITHIN THIS TROUGH THERE AREA A
COUPLE OF UPPER LOWS...A WEAKENING ONE OVER CENTRAL MN THAT BROUGHT
THE HEAVY RAINS TO WRN MN LAST NIGHT WITH AN MCV DOWN OVER CENTRAL
IA. AT THE SFC...OBS SHOW A WEAK LOW OVER CENTRAL MN UNDER THE
WEAKENING UPPER LOW. AT 2 PM...THE COLD FRONT EXTENDED SOUTH FROM
THE LOW THROUGH LITCHFIELD...WINDOM...AND INTO NW IA. THE MOST
WIDESPREAD PRECIPITATION THROUGH TONIGHT IS EXPECTED NORTH OF THE
MPX AREA WITH THE CENTRAL MN UPPER LOW AND WELL SOUTH OF MN/WI WITH
THE MCV. WE HAVE SEEN AN UNCAPPED 500-1000 J/KG OF MLCAPE DEVELOP
ALONG THE FRONT...WHICH HAS PROMOTED THE DEVELOPMENT OF A BROKEN
LINE OF STORMS ACROSS MN. HRRR AND MEMBERS 1 AND 3 OF THE HOPWRF
HAVE HAD A GOOD HANDEL ON THINGS TODAY...SO FOLLOWED THOSE MODELS
FOR TRACKING SHOWERS/STORMS ACROSS THE AREA. THIS RESULTED IN
SLOWING THE EWRD PROGRESSION OF POPS INTO WI...WHICH MAKES SENSE AS
ONCE AGAIN WE HAVE SEEN DEWPS OUT EAST DROP INTO THE MID 50S...DRY
AIR OUT THERE HAS BEEN VERY HESITANT TO LEAVE INDEED. BESIDE SLOWING
THE PROGRESSION OF POPS TO THE EAST...ALSO DECREASED POPS OVER WI
OVERNIGHT...AS SHOWERS REALLY LOOK TO LOOSE THEIR DEFINITION AFTER
SUNSET...WITH BEST FORCING WITH THE UPPER LOWS GOING INTO NRN WI AND
NRN IL OVERNIGHT. ALSO RESTRICTED POPS TO JUST WRN WI FOR MONDAY AND
HELD THEM INTO THE CHANCE CATEGORY AS WELL...AS UPPER WAVE DROPPING
DOWN OUT OF CANADA TONIGHT HEADS FOR CENTRAL WI MONDAY AFTERNOON. BY
THEN...BEST MOISTURE WILL BE MAINLY EAST OF THE MPX AREA...WITH
CURRENT REDUCED POPS POSSIBLY EVEN A BIT OVERDONE FOR MONDAY
AFTERNOON.
BESIDE BABYSITTING THE PRECIP ACROSS ERN AREAS TONIGHT...WILL ALSO
HAVE TO WATCH FOR FOG DEVELOPMENT OUT IN WRN MN. WE SAW A GOOD SWATH
OF 1-4+ INCHES OF RAIN OUT THERE OVERNIGHT AND AS WE GO THROUGH THE
NIGHT TONIGHT...SKIES WILL BEGIN TO CLEAR. HOWEVER...THIS CLEARING
WILL ALSO BE ACCOMPANIED BY DECREASING DEWPOINTS AND FAIRLY
PERSISTENT LIGHT NW WINDS. LEFT FOG OUT OF GRIDS FOR NOW THINKING
THESE NW WINDS WOULD KEEP THE ATMO MIXED ENOUGH TO KEEP FOG FROM
FORMING...BUT THEY WILL BE SUSCEPTIBLE TO FOG FORMATION GIVEN THE
RECENT HEAVY RAIN.
FOR MONDAY...OTHER THAN THE THREAT FOR SOME ISO/SCT STORMS OVER WRN
WI IN THE AFTERNOON...IT WILL BE YET ANOTHER STELLAR SUMMER DAY AS
SKIES CLEAR OUT...TEMPS WARM INTO THE MID/UPPER 70S...DEWPOINTS FALL
INTO THE 50S...ALL TOPPED OFF WITH A FRESH NNW WIND THAT WILL BE
GUSTING TO BETWEEN 20 AND 25 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
DRY WEATHER WILL CONTINUE THROUGH MUCH OF THE PERIOD UNTIL WARM
MOIST AIR RETURNS ACROSS THE REGION BY THE END OF THE WEEK. IN THE
MEAN TIME EXPECT LITTLE CHANGE FROM THE WEATHER EXPERIENCED OVER THE
PAST COUPLE OF WEEKS.
FROM A BROAD BRUSHED PERSPECTIVE...IN ORDER TO MAKE A CONFIDENT
FORECAST FOR WIDESPREAD PRECIPITATION ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE WARM SEASON YOU NEED EITHER LARGE SCALE
ASCENT IN THE FORM OF UPPER LEVEL DIVERGENCE...OR MORE COMMONLY LOW
LEVEL CONVERGENCE AND MOISTURE TRANSPORT ACROSS A FRONTAL BOUNDARY
FROM THE LOW LEVEL JET. OVER THE PAST FEW WEEKS NEITHER MN NOR WI
HAVE HAD EITHER...AND AS A RESULT THE WEATHER HAS BEEN NOTICEABLY
DRY.
A 36HR LOOP OF NORTH AMERICAN WATER VAPOR IMAGERY...TOGETHER WITH
GFS 500MB HEIGHTS AND WINDS SHOWED THE ACTIVE STORM TRACK SITUATED
TO THE NORTH ACROSS CENTRAL CANADA...WHILE RECURRING AFTERNOON
CONVECTION FIRED ACROSS THE CENTRAL CONUS ON THE LEE SIDE OF THE
ROCKIES OWING TO UPSLOPE FLOW. AS THE NIGHT PROGRESSED...THE
CONVECTION DRIFTED EASTWARD ACROSS THE PLAIN STATES OF NE AND KS.
ALTHOUGH ISOLATED AREAS OF WESTERN MN DID PICK UP HEALTHY RAINFALL
TOTALS OVER THE PAST 24HRS...THE COVERAGE WAS LIMITED TO A
RELATIVELY SMALL AREA...SIMILAR TO THE ISOLATED HEAVY RAIN THAT FELL
IN WESTERN WI THE PREVIOUS WEEK.
IN THE WAKE OF A WASHED OUT FRONTAL PASSAGE...THE REMAINDER OF THE
WORK WEEK WILL BE DRY AS NORTHWEST FLOW AND SURFACE HIGH PRESSURE
PERSIST ACROSS THE REGION. ON THURSDAY ANOTHER MCS WILL TRICKLE DOWN
THE MISSOURI RIVER VALLEY AND COULD CLIP THE SOUTHWESTERN PART OF
THE CWA. BY THE TIME THE WEEKEND ROLLS AROUND...EXTENDED MODELS
CONTINUE TO SHOW A TRANSITION TO A MORE ZONAL UPPER LEVEL PATTERN
WITH LOW LEVEL MOISTURE RETURNING FROM THE SOUTH. THIS WOULD
INCREASE THE POTENTIAL FOR PRECIP ACROSS THE REGION. IF THIS MODEL
SOLUTION PANS OUT HAVE FAIRLY HIGH CONFIDENCE THAT MOST OF THE
REGION WOULD PICK UP MEASURABLE RAINFALL DURING THE SATURDAY/SUNDAY
TIMEFRAME...BUT WILL NOT GO HIGHER THAN GUIDANCE WITH PRECIP CHANCES
UNTIL WE GET CLOSER TO THE EVENT CONSIDERING THE 12Z ECMWF FOCUSES
THE PRECIP TO THE SOUTHWEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 700 PM CDT SUN AUG 10 2014
THE LOW OVER CENTRAL MN WILL SLOWLY PUSH EAST THIS EVENING WITH
SHOWERS MOST CONCENTRATED OVER EAST CENTRAL MN AND NORTHWESTERN WI
TONIGHT. MORE SCATTERED ACTIVITY OVER SOUTHERN AND WESTERN MN WILL
DIMINISH IN THE NEXT COUPLE HOURS. MVFR CIGS ON THE BACKSIDE OF
THE UPPER LOW WILL PUSH SOUTH INTO STC/MSP/RWF/EAU LATER THIS
EVENING OR TONIGHT. DRIER AIR WILL FOLLOW FOR MONDAY MORNING WHEN
VFR CONDITIONS RETURN.
KMSP...SCATTERED SHOWERS WILL PERSIST FOR THE NEXT COUPLE HOURS.
THERE IS ONLY MEDIUM CONFIDENCE ON MVFR CIG POTENTIAL LATER THIS
EVENING AND OVERNIGHT...BUT IF THEY DO OCCUR THEY SHOULD BE OUT BY
EARLY MONDAY MORNING AS DRIER AIR BEGINS TO MOVE IN.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS W 5-10 KTS.
THU...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
327 PM CDT SAT AUG 9 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 323 PM CDT SAT AUG 9 2014
MAIN FEATURES OF INTEREST ON WATER VAPOR THIS AFTERNOON ARE A CLOSED
LOW OVER NE SODAK...AND A STRONG SHORT WAVE UP OVER SASKATCHEWAN.
THE CANADIAN WAVE HAS A COLD FRONT EXTENDING DOWN THROUGH THE
WESTERN DAKOTAS ASSOCIATED WITH IT. DURING THIS PERIOD...THE
CANADIAN WAVE WILL HEAD EAST TOWARD HUDSON BAY...WHILE THE SODAK
UPPER LOW DRIFTS OVER MN AND WASHES OUT IN THE BASE OF THE CANADIAN
TROUGH. AT THE SFC...THE COLD FRONT NW MN SUNDAY MORNING AND WILL BE
SLOWLY SINKING INTO CENTRAL MN BY THE AFTERNOON.
MAIN TREND FROM MODELS THIS EVENING WAS TO SLOW THE EWRD PROGRESSION
OF PRECIP...AS WEAK FLOW ALOFT KEEP ACTIVITY TIED TO THE PROGRESSION
OF THE UPPER LOW. THIS SLOWER EWRD PROGRESSION MAKES SENSE AS WELL
WHEN LOOKING AT DEWPOINTS...WHICH HAVE MIXED DOWN INTO THE MID/UPPER
50S ACROSS ERN MN/WRN WI THIS AFTERNOON...SO WILL TAKE A WHILE TO
DISLODGE THIS DRY AIR FROM THE I-35 CORRIDOR ON EAST. WITH GOOD
AGREEMENT WITH HI-RES MODELS ON PROGRESSION OF ACTIVITY IN ERN
SODAK/WRN MN INTO THE OVERNIGHT...UPPED POPS INTO THE LIKELY
CATEGORY OUT WEST...WHILE ALSO LIMITING THE EWRD PROGRESSION OF POPS
THROUGH THE WHOLE SHORT TERM PERIOD...KEEPING THE EAU CLAIRE AND
LADYSMITH AREAS DRY THROUGH THE SHORT TERM PERIOD.
NOT EXPECTING MUCH IN THE WAY OF SEVERE WEATHER DUE TO WEAK
SHEAR...LIMITED CAPE...AND LOW MID-LEVEL LAPSE RATES.
HOWEVER...THESE CONDITIONS WILL LEAD TO SLOW MOVING EFFICIENT RAIN
PRODUCERS...WITH LOCALIZED HEAVY RAINFALL POSSIBLE...ESPECIALLY THIS
AFTERNOON AND EVENING. THE HRRR AND HOPWRF MEMBERS HAVE BEEN SHOWING
THIS HEAVY RAIN SIGNAL MOST OF THE DAY...WITH 2-4+ INCHES OF RAIN
NOTED FROM NE SODAK INTO YELLOW MEDICINE/LAC QUI PARLE COUNTIES.
MAKES SENSE WITH SLOW STORM MOTION...FAIRLY STATIONARY FORCING...AND
PWATS OVER 1.5 INCHES THROUGH THE NIGHT. THOUGH NOT AS HIGH ON
AMOUNTS...THE DETERMINISTIC MODELS ARE HIGHLIGHTING THE SAME AREA
FOR HEAVY RAIN THROUGH TONIGHT AS WELL...SO GAVE BOTH POPS AND QPF A
BIG BOOST IN WEST CENTRAL MN THROUGH TONIGHT.
THROUGH SUNDAY...WITH THE FRONT SLOWLY WORKING INTO MN...WILL SEE
PERIODS OF SHOWERS AND STORMS ALL DAY WEST OF I-35. HAVE CONTINUED
TO FAVOR LIKELY POPS ACROSS CENTRAL MN...AS THIS IS WHERE MODELS
SHOW THE NOSE OF AN INVERTED TROUGH DEVELOPING IN ASSOCIATION WITH A
SFC LOW THAT WILL BE SLOWLY DEEPENING ACROSS THE CENTRAL PLAINS. BY
SUNDAY AFTERNOON...THE WAVE CURRENTLY OVER SODAK WILL BE MUCH LESS
DEFINED...WITH PRECIPITATION LIKELY MORE WIDESPREAD AND LIGHTER THAN
WHAT WE ARE SEEING TODAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 PM CDT SAT AUG 9 2014
THE FORECAST PERIOD LOOKS TO BE BRACKETED BY SOME PCPN CHANCES ON
EITHER END... WITH A SOMEWHAT PROGRESSIVE LARGE SCALE PATTERN OVER
THE COURSE OF THE WEEK. WE/LL SEE AN UPPER TROUGH AMPLIFY JUST TO
OUR EAST AT THE START OF THE PERIOD AS THE SHORTWAVE WHICH WILL
BRING SOME PCPN THROUGH OUR AREA SUNDAY NIGHT INTO EARLY MONDAY
SHIFTS EASTWARD. HOWEVER... THAT FEATURE LOOKS TO LIFT NORTHEAST BY
MIDWEEK AS AN UPPER RIDGE MOVES INTO OUR AREA FROM THE NORTHERN
ROCKIES AND HIGH PLAINS. THINGS THEN DE-AMPLIFY A BIT BY THE END OF
THE WEEK AND THE FLOW LOOKS TO BECOME FAIRLY ZONAL ACROSS THE
NORTHERN CONUS. HOWEVER... THERE ARE FAIRLY SIGNIFICANT DIFFERENCES
IN THE EXTENDED GUIDANCE BY THAT POINT... AND RUN-TO-RUN CONSISTENCY
HASN/T BEEN THE GREATEST IN ANY OF THE MODEL SUITES. WILL GENERALLY
FOLLOW A BLEND OF THE ECMWF AND GFS SOLUTIONS WITH A BIT MORE WEIGHT
ON THE ECMWF WHICH HAS BEEN SLIGHTLY MORE CONSISTENT IN THE SYSTEM
PROGGED TO IMPACT THE AREA BY THE WEEKEND.
FRONTAL BOUNDARY WILL BE TRAVERSING THE AREA SUNDAY NIGHT... WITH
FAIRLY WIDESPREAD SHRA ACTIVITY EXPECTED ALONG WITH SOME EMBEDDED
THUNDERSTORMS. THE BEST LARGE SCALE FORCING IN TERMS OF DPVA AND
UPPER DIVERGENCE LOOKS TO BE MAINLY TO OUR NORTH. HOWEVER... THE
THALER QG DIAGNOSTICS STILL BRING A DECENT SLUG OF FORCING THROUGH
THE AREA... WHICH SHOULD BE SUFFICIENT TO PRODUCE SOME PCPN FOR
MOST OF THE AREA GIVEN THE DECENT MOISTURE/INSTABILITY THAT WILL
BE IN PLACE. PCPN WILL LINGER OVER THE EASTERN PORTION OF THE AREA
INTO MONDAY AS THE BOUNDARY SLOWLY MOVES EAST. HIGH PRESSURE WILL
THEN BUILD INTO THE AREA FOR THE MIDDLE OF THE WEEK... WITH DRY
WEATHER AND SEASONABLE OR SLIGHTLY BELOW NORMAL TEMPERATURES
REMAINING IN PLACE THROUGH THURSDAY. WE/LL THEN SEE RETURN FLOW
AND ISENTROPIC LIFT SETUP FROM WEST TO EAST THURSDAY NIGHT INTO
FRIDAY... WHICH WILL BRING A RENEWED CHANCE FOR SHRA/TSRA. THERE
IS QUITE A BIT OF UNCERTAINTY ON IF/WHEN THE COLD FRONT WILL PUSH
BACK THROUGH THE AREA AFTER WE SEE THE WARM ADVECTION AND WORK
INTO THE WARM SECTOR. THE ECMWF IS LESS AGGRESSIVE IN PUSHING THE
BOUNDARY THROUGH... AND SUGGESTS IT COULD BE STRUNG OUT FROM WEST
TO EAST ACROSS THE AREA BY SUNDAY WHILE THE GFS INDICATES MORE OF
AN UPSTREAM TROUGH AND PROGRESSIVE LOOK TO THINGS. HOWEVER... IN
EITHER CASE IT LOOKS LIKE WE/D NEED TO LINGER SOME POPS THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CDT SAT AUG 9 2014
SHRA/TSRA ACTIVITY THIS PERIOD WILL BE TIED TO THE UPPER LOW
CURRENTLY NEAR KABR. THIS WILL KEEP ACTIVITY MAINLY WEST OF ALL
TAF SITES UNTIL AFTER 6Z...WHEN THE UPPER LOW BEGINS TO SHIFT INTO
WRN MN AHEAD OF A COLD FRONT ADVANCING EAST ACROSS THE DAKOTAS.
STILL ENOUGH UNCERTAINTY ON EXACT TIMING/PLACEMENT OF SHOWERS IN
THE TAF PERIOD TO HOLD BACK ANY PRECIP MENTION INTO THE VCSH OR
SHRA RANGE. MVFR AND LOWER CONDITIONS NOT EXPECTED UNTIL LATE
TONIGHT/EARLY SUN MORNING AT WRN TERMINALS AS MOISTURE INCREASES
AHEAD OF THE DAKOTAS COLD FRONT. WITH HIGH PRESSURE REMAINING OVER
THE GREAT LAKES...WE WILL BE MAINTAINING A FAIRLY CONSISTENT SE WIND.
KMSP...MAY HAVE A SPRINKLE OR TWO THROUGH THE AFTERNOON...THOUGH
ANYTHING OF MORE SIGNIFICANCE IS NOT EXPECTED UNTIL SUN AFTERNOON.
ANY PRECIP SEEN SUNDAY MORNING WOULD BE THE REMNANTS OF WHAT IS
EXPECTED OUT IN WRN MN TONIGHT. HOWEVER...VERY WEAK FLOW WILL
LIKELY KEEP MOST ACTIVITY TIED TO THE UPPER LOW...WHICH DOES NOT
WANDER OVER TO ERN MN UNTIL THE AFTERNOON. HENCE THE PROB30 FOR
TSRA STARTING AT 20Z.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS WITH SCT SHRA/ISO TSRA IN MORNING. BECOMING VFR IN
AFTERNOON NNW WINDS 10-15KTS.
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...MPG
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1031 AM CDT SAT AUG 9 2014
.UPDATE...VISIBLE IMAGERY INDICATING A CHAOTIC SKY OVER N MS THIS
MORNING IN ADVANCE OF CONVECTION OVER AR/W TN. WHILE WET MICROBURST
CHECKLIST IS ONLY INDICATING A RISK FOR THIS AFTERNOON...LOCAL WRF
AND TO SOME EXTENT THE HRRR IS INDICATING SOME MICROBURST POTENTIAL.
UPPED POPS TO LIKELY CATEGORY FOR EXPECTED INCREASED CCOVERAGE DUE TO
ABUNDANT BOUNDARY INTERACTION. ALSO...INTRODUCED A LIMITED CONFIDENCE
OF SEVERE IN THE HWO FOR THE WESTERN TWO THIRDS OF THE AREA./26/
&&
.AVIATION...VFR CONDITIONS PREVAIL THIS MORNING WITH TSRA COMPLEX
DEVELOPING NOW OVER CNTRL AR. SCT/NUM TSRA SHOULD DEVELOP SOUTHEAST
LATE MORNING THROUGH THE AFTERNOON WITH PERIODIC MVFR AND BRIEF IFR
POSSIBLE IF SITE IS DIRECTLY IMPACTED. VCTS TAF WORDING WORKS FOR NOW
AND WILL AMEND AS NEEDED WHEN CONFIDENCE IN DIRECT IMPACT INCREASES.
WINDS WILL BE W TO WNW GENERALLY LESS THEN 10 KT. WINDS COULD MORE
GUSTY /UP TO 30-40 KT/ IF INVOF STRONGER TSRA. /ALLEN/
&&
.PREV DISCUSSION... /ISSUED 502 AM CDT SAT AUG 9 2014/
DISCUSSION...
ON THE SYNOPTIC SCALE THIS WEEKEND...THE ARKLAMISS WILL BE NEAR THE
INTERFACE OF ACTIVE WESTERLIES TO THE NORTH AND A HOT SUBTROPICAL
RIDGE CENTERED TO THE WEST. THIS WILL TRANSLATE TO HOT AND HUMID
SENSIBLE WEATHER WITH GREATER CHANCES FOR MAINLY DIURNAL SHOWER/TSTM
ACTIVITY AS THE PATTERN BEGINS TO AMPLIFY AND ALLOWS A FRONTAL
BOUNDARY TO HAVE MORE INFLUENCE. WITH THAT SAID...FORECAST
CONFIDENCE IS LOWER THAN USUAL TODAY REGARDING CONVECTIVE EVOLUTION
AND POSSIBLE MITIGATING EFFECTS ON HEAT STRESS.
CONVECTIVE CLOUD DEBRIS OVER AR IS CIRCULATING AROUND THE RIDGE
CENTER AND COULD HELP TO PROVIDE SOME DIFFERENTIAL HEATING LATER
THIS MORNING FOR CONVECTIVE INITIATION. WRF/HRRR GUIDANCE ARE IN
CONSIDERABLE DISAGREEMENT OVER HOW THINGS WILL PLAY OUT...AND NONE
OF THE MODELS SEEM TO HAVE A GOOD HANDLE ON THE CURRENT SCENARIO.
BASED ON THE LATEST TRENDS...WILL PLAN TO FOLLOW THE IDEA OF
CONVECTION DEVELOPING EARLIER OVER THE UPPER DELTA REGION INTO NORTH
CENTRAL MS...WITH MULT-CELL STORM CLUSTERS/SEGMENTS INCREASING IN
COVERAGE THE AFTERNOON. UPPER LEVEL WINDS ARE LIGHT AND IT IS HARD
TO IMAGINE THE STORMS GETTING VERY ORGANIZED...BUT SHOULD BE ENOUGH
LOW-MID LEVEL FLOW AND OUTFLOW DEVELOPMENT TO ALLOW STORMS TO
PROGRESS SOUTHWARD AS WE GO THROUGH THE AFTERNOON. MOREOVER...LOW
LEVEL FLOW/THETA-E ADVECTION MAY ALLOW STORMS TO BACK-BUILD MORE
THAN FORECAST. THIS COULD SLOW THE OVERALL SYSTEM SPEED AND INCREASE
THE HEAVY RAIN POTENTIAL. IN ANY CASE...STEEP LOW-MID LEVEL LAPSE
RATES WITH VERTICAL TOTALS ~27 WILL SUPPORT A FEW STRONG TO SEVERE
STORMS ESPECIALLY WHERE THE CONVECTION IS MORE DELAYED.
EVEN WITH EARLIER CONVECTIVE DEVELOPMENT TODAY...THE FORECAST
TEMP/DEWPOINT COMBINATIONS YIELD HEAT INDICES NEAR 100-102 DEG F AT
MOST PLACES. WHILE THIS IS A LITTLE LOW FOR MENTION IN THE HAZARD
PRODUCTS...WE EXPECT GREATER HEAT STRESS TO RETURN SUNDAY SO WOULD
RATHER KEEP CONTINUITY AND LEAVE IT GOING FOR TODAY. EXPECT
CONVECTION TO DIMINISH THIS EVENING AS THE SUBTROPICAL RIDGE REMAINS
THE PRIMARY SYNOPTIC SCALE INFLUENCE FOR THE ARKLAMISS. ANOTHER
ROUND OF STORMS IS EXPECTED SUNDAY...BUT THERE HAS BEEN A TREND IN
THE GUIDANCE FOR THIS ACTIVITY TO BE MORE FOCUSED OVER SOUTHERN
PORTIONS OF THE AREA. SIMILAR THERMODYNAMIC PARAMETERS TO SATURDAY
WILL SUPPORT A FEW STRONG TO SEVERE STORMS ONCE AGAIN. /EC/
FOR THE MED RANGE/LONG TERM (MON-SAT)...THE FORECAST FOCUS WILL BE ON
THE ACTIVE CONVECTIVE PERIOD FOR MON/MON NGT AS THE REGION
UNDERGOES A PATTERN CHANGE. BY MID WEEK...LOOK FOR A MORE QUIET
REGIME WITH LOWER HUMIDITY BEFORE WARMER CONDITIONS RETURN BY NEXT
WEEKEND.
THE EVOLVING NW FLOW PATTERN FOR THE UPCOMING WEEK LOOKS TO BRING
SOLID PRECIP CHANCES TO THE AREA FOR MON INTO MON NGT. THIS WILL BE
AS DEEP MOISTURE POOLS IN ADVANCE OF A WEAK SFC FRONT AND AHEAD OF
AN AMPLIFYING LONG WAVE TROUGH THAT WILL SETUP ACROSS THE EASTERN
CONUS THIS WEEK. SPECIFICS ON STORM TIMING REMAINS A CHALLENGE AS
MODEL DIFFERENCES EXIST. THE NAM/EURO DEVELOP ACTIVITY EARLIER ON
MON AND CONTINUE SOME SORT OF PRECIP INTO THE NIGHT. THE GFS DELAYS
INITIATION UNTIL THE AFTERNOON WITH ACTIVITY LINGERING INTO MON NGT.
THE MAIN ISSUE WITH THE DIFFERENCE SCENARIOS IS THE IMPACT ON HIGH
TEMPS AND ULTIMATELY INSTABILITY. THE NAM/EURO HAVE MUCH LESS HOT
CONDITIONS WITH READINGS AROUND 90 FORECAST FOR HIGHS. THE GFS IS
THE HOTTER SOLUTION WITH 94-96. WITH SOME LINGERING EFFECTS OF THE
RIDGE IN PLACE...I WILL LEAN MORE TOWARD THE GFS. THIS WILL RESULT
IN A BETTER CHANCE FOR STRONG/SVR STORMS AS STRONGER SFC HEATING
WILL RESULT IN HIGHER INSTABILITY. EVEN AS SOME CONFIDENCE EXISTS IN
POTENTIAL FOR MON...WILL HOLD OFF ON ADDING GRAPHICS OR TEXT IN THE
HWO AS THERE REMAINS STILL ENOUGH UNCERTAINTY TO JUMP ON THIS FOR
DAY 3.
THE NW FLOW PATTERN WILL REALLY TAKE HOLD OF THE REGION BY TUE WITH
ALL MODELS SHOWING A WELL DEFINED MID LEVEL DRY PUSH MOVING SOUTH
INTO THE AREA. THIS WILL SERVE TO HELP THE WEAK SFC FRONT TO MAY
HEADWAY WELL INTO THE CWA ON TUE...THEN BRING SOME DRIER LOW LEVEL
AIR IN ITS WAKE. PRECIP ACTIVITY ON TUE WILL MAINLY BE CONFINED TO
THE SOUTH HALF AND MOST LIKELY EARLY IN THE DAY PERIOD. AS WE GO
INTO AND THROUGH MID/LATE WEEK...THE NW FLOW PATTERN WILL RELAX AND
RIDING LOOKS TO BUILD OVER THE LOWER MS RIVER VALLY INTO THE
WEEKEND. THIS SHOULD SUPPORT SOME NEAR NORMAL OR SLIGHTLY BELOW
NORMAL HIGHS FOR WED/THU ALONG WITH LESS HUMID READINGS. BY
FRI/SAT...A RETURN TO MORE NORMAL CONDITIONS ARE EXPECTED. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 93 74 94 74 / 63 34 48 32
MERIDIAN 94 73 93 73 / 70 39 44 29
VICKSBURG 93 74 93 73 / 65 27 49 24
HATTIESBURG 95 75 94 75 / 59 33 63 34
NATCHEZ 92 74 92 75 / 58 29 54 20
GREENVILLE 90 74 94 75 / 70 24 43 30
GREENWOOD 91 73 94 74 / 70 25 39 28
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
627 PM CDT Sun Aug 10 2014
...Mesoscale Convective Discussion and Aviation Update...
.MESOSCALE DISCUSSION...
Issued at 602 PM CDT SUN AUG 10 2014
Recent radar trends suggest that thunderstorms are struggling to
expand in coverage despite the presence of boundaries and an
incoming short wave trough from the northwest. The orientation and
movement to the boundaries is likely playing a role in the lack of
coverage. One boundary which extends from near Osceola to
Hartville is moving against low level shear vectors. Low level
destructive interference is likely squashing new updraft
development. A second boundary is more west/east oriented and is
seeping south from extreme northern Bourbon County into the
Osceola area. We have seen weak convection develop along this
feature as shear vectors are oriented more parallel (not
inhibiting updrafts). Another negative across central Missouri is
an overall lack of instability.
As we head into this evening, the current widely scattered
convection will tend to slowly weaken with waning instability. We
will see the continued potential for weaker convective development
as that west/east boundary and upper level wave push south and
east. Overall, we have lowered PoPs over most areas, with the
biggest adjustments to southwestern Missouri and extreme
southeastern Kansas. Any threat for strong to severe storms will
generally occur over the next hour or two and be associated with
convection moving southeast across portions of south-central
Missouri. Despite lower-end deep layer shear, one cell has shown
supercellular structures for the last couple of hours. Thus, we
will maintain a limited hail and wind threat into early this
evening.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 300 PM CDT SUN AUG 10 2014
Warm and humid conditions are in place across the region this
afternoon. Starting to see an uptick in convection during the
past hour, particularly across central Missouri. This is in
response to destabilization due to daytime heating and upper level
energy rotating around an area of low pressure located near Kansas
City. Water vapor imagery and RAP initializations of mid level
vorticity indicate multiple lobes of vorticity emanating from this
upper low. As a result, we should continue to see a gradual
increase in showers and storms across much of the Missouri Ozarks
heading into this evening. The aforementioned upper low and a cold
front moving into the region from the northwest will maintain
scattered showers and storms across the region into much of
tonight. Overnight the better rain chances should begin to shift
to the southeast and east.
High PW air in place (around 1.9" according to the SPC
mesoanalysis page) will result in locally heavy rainfall with this
activity. Deep layer shear remains on the weak side, around 25-30
kt, while both surface based and mixed layer CAPE values are
nearing 3000 J/kg. This should result in a mainly multicell
convective mode with an isolated risk for wet microbursts.
The cold front will exit to the east/southeast on Monday with rain
chances ending during the morning hours.
.LONG TERM...(Monday Night through Sunday)
Issued at 300 PM CDT SUN AUG 10 2014
A nice stretch of weather is expected across the area from Monday
night through Thursday as large area of Canadian surface high
pressure dominates our weather regime. Temperatures will some 7 to
10 degrees below average with comfortable humidity levels.
Temperatures and humidity will rebound back to typical mid-August
values late this week through next weekend as the upper level
pattern flattens a bit. Upper level ridging will attempt to build
into the region from the southwest, meanwhile energy in the
northern stream will threaten to enter from the northwest. Day to
day continuity from individual medium range models have been
lacking (one run wet, the next run dry), however the consensus
suggests that the door will be open to mesoscale convective
systems (MCS) entering from the northwest. As a result, have
continued low end chance PoPs from Friday through the weekend
until finer scale details can be resolved.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 602 PM CDT SUN AUG 10 2014
Isolated showers and thunderstorms will remain possible this
evening as an upper level disturbance approaches from the
northwest. Coverage is expected to be too limited to include
thunderstorms in the TAFs. Some weather models have then
increased the potential for MVFR and potentially IFR cloud cover
later tonight behind a passing frontal boundary. The greatest
potential for IFR will be around Springfield as northwesterly
surface winds and the local topography will promote upslope flow.
Confidence in IFR is lower at Joplin and Branson. Any lower
ceilings will then lift Monday morning with VFR returning by late
morning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Schaumann
SHORT TERM...Gagan
LONG TERM...Gagan
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1157 PM CDT Fri Aug 8 2014
.DISCUSSION...
Issued at 402 PM CDT FRI AUG 8 2014
Tonight-Saturday:
Weak zonal flow resulting in fairly quiet weather next 30 hours. In
the very near term what`s left of a weak MCV moving into northwest MO
late is likely to generate little if any precipitation as the feature
works its way through a stable environment. Main concern is how long
stratus will linger as well as fog potential. Considering how moist
the boundary layer is plus light winds under a nocturnal inversion
believe conditions favor fog development. SREF visibility prog and
UPS fog output also support fog formation. Pockets of dense fog
certainly possible in locally favored regions. RUC and NAM
condensation pressure deficit progs also maintain low clouds over at
least northeast MO through the night.
Saturday looks rain-free with warmer temperatures, albeit still
below normal, owing to the likelihood of seeing sunshine.
Saturday night-Sunday night:
This period still holds our best chance of seeing convective
activity. The upper flow remains weak and zonal. However, the
GFS/NAM/ECMWF have shown continuity/consistency with a weak shortwave
trough coming out of the southeast WY/NE Panhandle area late Saturday
afternoon/evening. These models track the feature ese and generate a
convective complex. The southerly low level jet is not particularly
strong nor is there a frontal boundary to enhance the low-level
convergence so how long the convection holds together is still
debatable. For now, can justify increasing PoPs over the western CWA
late Saturday night and Sunday. Of interest is the ECMWF and LSX`s
local WRF models which generate a second and possible stronger area
of convection with a cold front that drags through the region late
Sunday afternoon and evening. Lacking confirmation from the NAM and
GFS prevents me from ratcheting up PoPs for this period but it does
bear watching. Heavy rainfall may need to be considered in later
forecasts once there is a better handle on the longevity of possible
MCS. Max temperatures will likely be problematic due to precipitation
and cloud cover distribution. Did trend them lower over the northern
and western CWA.
Monday-Thursday:
An old friend is about to revisit us as the upper flow transition
once again to a sharpening upper trough from the Great Lakes through
the OH Valley and the upper ridge pumping up over the Rockies. This
will leave us in northwest flow aloft as well as on the east side and
northerly winds of a surface high spreading across the central U.S.
This pattern has repeated itself several times this summer and has
resulted in much cooler than average temperatures. Models are
trending this way but look too slow/warm initially....which is
typical. So, have lowered temperatures during this period. Should be
a dry period although widely scattered convection could pop up mainly
Monday afternoon as a weak vorticity lobe drops through IA and
eastern half of MO.
Thursday night-Friday:
The Rockies upper ridge shows signs of breaking down with a possible
shortwave trough shoving east through the Central Plains. This is
enough to add in some chance PoPs as well as allow temperatures to
warm closer to seasonal averages.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1157 PM CDT FRI AUG 8 2014
MVFR to IFR stratus will continue to sit just east of the TAF sites
tonight, although a few scattered areas of MVFR ceilings may briefly
drift through the terminals over the next few hours. Widespread
patchy fog is expected to develop across the area, but the lowest
visibilities may occur on the west side of the stratus deck at MCI
and STJ. Fog should dissipate by 13-14z Saturday morning, leaving the
area VFR for the remainder of the TAF period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS GLASGOW MT
938 AM MDT SAT AUG 9 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
UPDATE...
A LINE OF SHOWERS IS TRANSLATING EAST ACROSS THE CWA THIS MORNING.
NOT MUCH LIGHTNING ASSOCIATED WITH THIS AT THE PRESENT THOUGH
DECIDED TO LEAVE THUNDER IN THE GRIDS AS A RUMBLE OR TWO OF
THUNDER CANNOT BE RULED OUT ENTIRELY. THE BAND IS NARROWING AS IT
PUSHES EAST AND BECOMING LESS CONTINUOUS S IT EXTENDS FROM JUST
WEST OF THE PORT OF OPHEIM SOUTHWEST THROUGH WESTERN VALLEY
COUNTY AND WESTERN GARFIELD. THE HRRR CAPTURES THE EVOLUTION OF
THIS FEATURE WELL AND ADJUSTED POPS TO BETTER REFLECT CURRENT
OBSERVATIONS AND NEAR TERM EXPECTATIONS. FOR THIS AFTERNOON A
DECENT CHANCE OF THUNDERSTORMS EXIST NEAR THE MT/ND BORDER...IN
PARTICULAR LOCATIONS SOUTH OF SIDNEY AND EAST OF MCCONE COUNTY.
WINDS ARE ALSO HIGHER THAN GUIDANCE THIS MORNING...REFLECTIVE OF
COLD AIR ADVECTION BEHIND THE FROPA HELPING TO MIX DOWN SOME OF
THESE HIGHER GUSTS. THUS...LAKE WIND HEADLINES LOOK GOOD FOR FORT
PECK LAKE. MALIAWCO
PREVIOUS SHORT TERM DISCUSSION...
VERY GOOD MODEL AGREEMENT REPRESENTS AND SUPPORTS THUNDERSTORMS
TODAY ACROSS OUR CWA FROM WEST TO EAST THANKS TO A SHORT-WAVE
DISTURBANCE NOW EMERGED FROM THE NORTHERN ROCKIES. ALSO EXPECTING
NORTHERLY WINDS BEHIND THE ATTENDANT COLD FRONT OF 15 TO 20 MPH
SUSTAINED WITH GUSTS UP TO 30 MPH POSSIBLE. DECIDED TO ISSUE A
LAKE WIND ADVISORY FOR TODAY FROM 10 AM TO 8 PM TO COVER THESE
WINDS ACROSS THE LAKE. COOLER TEMPERATURES BEHIND THE FRONT WILL
REMAIN HERE TODAY AND TOMORROW.
TONIGHT...AS THE DISTURBANCE LIFTS NORTHEASTWARD TOWARD THE CENTRAL
CANADIAN PRAIRIE...HIGH PRESSURE WILL SETTLE OVER NORTHEAST
MONTANA...CLEARING THE SKIES AND KEEPING PRECIPITATION AWAY FROM
THE AREA THROUGH THE REMAINDER OF THE FORECAST PERIOD. NORTHWEST
FLOW ALOFT RETURNS AND A STRONG AND SUBSTANTIAL RIDGE OF HIGH
PRESSURE SETS UP THROUGH THE ENTIRE ROCKY MOUNTAIN REGION. WARMER
AND DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION BEGINNING
NEXT WEEK. BMICKELSON
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
EXTENDED PERIOD OPENS WITH UPPER RIDGE STRETCHED ALONG THE ROCKIES
FROM MEXICO TO ALASKA RESULTING IN HOT AND DRY CONDITIONS FOR
EASTERN MONTANA FOR TUESDAY AND MOST OF WEDNESDAY.
MEDIUM RANGE MODELS MOVING TOWARD BETTER CONSENSUS FOR LATE IN THE
WEEK WITH RIDGE BREAKING DOWN AS UPPER TROF MOVES ACROSS THE
PACIFIC NORTHWEST. MODEL SOLUTIONS RANGE FROM A CLOSED UPPER LOW
MOVING ACROSS MONTANA TO A FLATTER TROF BUT GENERAL TREND IS FOR
SOME SORT OF POSITIVE TILTED TROF MOVING THROUGH THE REGION.
RESULT WILL BE SLIGHTLY COOLER TEMPERATURES AND MORE POTENTIAL FOR
THUNDERSTORMS FROM MIDWEEK INTO THE WEEKEND. EBERT
&&
.AVIATION...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NEAR KGGW EARLY THIS
MORNING WILL SPREAD TO KOLF...KSDY AND KGDV BY THE AFTERNOON AS A
COLD FRONT MOVES THROUGH EASTERN MONTANA. WINDS WILL SWITCH TO
N-NW AROUND 10 TO 20 MPH AS THE FRONT PASSES.
VFR CONDITIONS EXPECTED... BRIEF REDUCTIONS IN VISIBILITY MAY BE
POSSIBLE IF HEAVIER SHOWERS PASS OVER TERMINAL SITES.AEC
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
926 AM MDT SAT AUG 9 2014
.UPDATE...
MINOR CHANGES TO THE GOING FORECAST THIS MORNING...MAINLY TO
ADJUST POPS AND CLOUD COVER FOR CURRENT COLD FRONTAL POSITION.
AFOREMENTIONED COLD FRONT IS CURRENTLY LOCATED FROM NEAR MILES
CITY TO JUST SOUTHEAST OF SHERIDAN WYOMING. NORTHWEST WINDS HAVE
FILLED IN BEHIND THIS BOUNDARY AND WILL SEE OCCASIONALLY GUSTY
NORTHERLY WINDS ACROSS THE AREA THIS AFTERNOON. CONVECTION
ASSOCIATED WITH THE FRONT ON RADAR LOOKS WORSE THAN IT IS WITH
MAINLY SPRINKLES AT THIS POINT. RESIDUAL INSTABILITY BEHIND THE
FRONT WILL BRING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
THIS AFTERNOON...BUT SHOULDN`T BE MORE THAN A NUISANCE FOR OUTDOOR
PLANS. BEST AREA FOR PRECIPITATION WILL BE MOUNTAINS AND AREAS
EAST OF A MILES CITY TO BROADUS LINE THIS AFTERNOON AND EVENING.
LATEST GUIDANCE KEEPS TEMPERATURES CLOSE TO 80 DEGREES FOR MOST
AREAS THIS AFTERNOON SO BUMPED TEMPERATURES DOWN JUST A FEW
DEGREES FOR TODAY. CHAMBERS
&&
.SHORT TERM...VALID FOR TDY AND SUN...
A COLD FRONT WILL CROSS THE AREA TODAY WITH SOME CHANCE OF SHOWERS
AND STORMS...THOUGH NEITHER THE FRONTAL PASSAGE OR CONVECTION WILL
PROBABLY BE ANYTHING TO WRITE HOME ABOUT.
TODAY...THE SURFACE COLD FRONT WHICH HAS PASSED THROUGH BOTH HAVRE
AND GREAT FALLS AS OF 09 UTC WILL CONTINUE MOVING SOUTHEAST THANKS
TO THE PASSAGE OF A 500-MB SHORTWAVE TROUGH. THERE ARE 3 MB/3 HOUR
SURFACE PRESSURE RISES BEHIND THE FRONT AT 09 UTC AND WEAK SHOWERS
AND STORMS HAVE BEEN GOING ON OVERNIGHT IN NORTH CENTRAL MT...BOTH
OF WHICH MAY SIGNAL A BIT BETTER FRONTAL PUSH AND STRONGER COOLING
IN ITS WAKE THAN GUIDANCE SUGGESTS. WE THUS REDUCED HIGHS SOMEWHAT
TODAY AND PUSHED POST-FRONTAL WIND SPEEDS HIGHER THAN MOS GUIDANCE
ALONE WOULD SUGGEST. BOTH OF THOSE ADJUSTMENTS MIGHT NOT HAVE BEEN
ENOUGH...BUT THE CORE OF HEIGHT FALLS WITH THE SHORTWAVE WILL STAY
IN CANADA AND 850-MB COLD AIR ADVECTION IS NOT VERY ROBUST LIKE WE
TYPICALLY SEE IN CASES WHERE GUIDANCE UNDER DOES FRONTAL SURGES.
IT THUS SEEMED APPROPRIATE TO NOT SWING TOO HARD IN ANY ONE
DIRECTION WITH THE GRIDDED FORECAST UNTIL MESOSCALE TRENDS ARE
SOLIDIFIED.
WHERE SHOWERS AND STORMS ARE CONCERNED...SHORT-RANGE GUIDANCE LIKE
THE 06 UTC HRRR TAKES THE SHOWERS AROUND HARLOWTON AT 09 UTC EAST-
SOUTHEAST THIS MORNING. BY AFTERNOON...THE FRONTAL ZONE WILL BE IN
SOUTHEASTERN MT AND SHOULD SERVE TO INCITE SHOWERS AND STORMS ON A
MORE SCATTERED BASIS FROM MILES CITY AND BROADUS EAST TO BAKER AND
EKALAKA. FORECAST SOUNDINGS IN THOSE AREAS SHOW MLCAPE AROUND 1200
J/KG...BUT 0-6-KM BULK SHEAR OF 20 KT...SUGGESTIVE OF SOME LOCALLY
HEAVY RAIN AND BRIEF STRONG STORMS...BUT VERY LOW SEVERE RISK. THE
00 UTC SPC SSEO IS ON BOARD WITH THIS IDEA WITH THE STORM COVERAGE
GREATEST IN FALLON AND CARTER COUNTIES FROM 21 TO 00 UTC. THE SSEO
AND IN PARTICULAR THE OFTEN-WELL-PERFORMING NSSL WRF-ARW /WHICH IS
A COMPONENT OF THE SSEO/ ALSO SUPPORTS ISOLATED TO MAYBE SCATTERED
SHOWERS AND STORMS OVER THE REST OF THE AREA THIS AFTERNOON TOO.
TONIGHT...SOME CONVECTION MAY LINGER INTO THE EVENING...BUT SHOULD
LARGELY DIMINISH BY 03 UTC AS FORCING SHIFTS INTO ND AND THE LOWER
ATMOSPHERE STABILIZES IN ITS WAKE. BOTH THE 00 UTC SPC SSEO OUTPUT
AND CONVECTIVELY-PARAMETERIZED GFS AND ECMWF SOLUTIONS SUPPORTED A
DRY FORECAST IN MANY AREAS AFTER 03 UTC /9 PM MDT/.
SUN...HIGHS WILL WARM BACK UP WELL INTO THE MID AND UPPER 80S F IN
MOST AREAS UNDER HEIGHT RISES ALOFT. WE RAISED FORECAST HIGHS SOME
5 TO 8 F USING THE 00 UTC MULTI-MODEL CONSENSUS...BUT THE FORECAST
STILL LAGS THE WARMER BIAS-CORRECTED GUIDANCE A BIT. WE EXPECT ANY
CONVECTION TO BE ISOLATED AND CONFINED TO NEAR THE HIGH TERRAIN AS
THE LARGE-SCALE HEIGHT RISES WILL PROVE DETRIMENTAL TO ACTIVITY IN
THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
UPPER LEVEL RIDGING ACROSS THE WESTERN PORTION OF THE US WILL
KEEP EARLY TO MID WEEK SURFACE TEMPERATURES IN THE LOW TO MID 90S
ACROSS SC AND SE MONTANA. HEIGHTS BEGIN TO LOWER BY WEDNESDAY AS
THE RIDGE BREAKS DOWN IN LIEU OF LOW PRESSURE MOVING IN OFF THE
COAST OF BRITISH COLUMBIA. MODELS DIFFER SOMEWHAT ON THE STRENGTH
OF THE LOW...BUT EITHER WAY CIRCULATION AROUND IT WILL BRING
SOUTHWESTERLY FLOW TO THE REGION BY THURSDAY. THIS WILL ALLOW A
CONDUIT FOR THE TAP OF SOME MONSOONAL MOISTURE FROM THE DESERT
SOUTHWEST AND BRING SOME POTENTIAL...MUCH NEEDED...PRECIPITATION
TO THE REGION. RAISED POPS ACCORDINGLY TO ACCOUNT FOR THIS.
NORTHWESTERLY FLOW WILL AGAIN DOMINATE BY NEXT WEEKEND...CUTTING
OFF THE POTENTIAL FOR ADDITIONAL PRECIPITATION. SINGER
&&
.AVIATION...
A LINE OF SHOWERS EXTEND FROM NORTH TO SOUTH ACROSS THE
REGION. THIS LINE IS JUST EAST OF KBIL...EAST EXTENDING THROUGH
MUSSELSHELLAND FORT SMITH. ISOLATED THUNDERSTORMS ARE ALSO
POSSIBLE TODAY AT ALL TERMINALS WITH THE PASSAGE OF A SURFACE COLD
FRONT. CURRENTLY THE BEST CHANCE FOR PRECIPITATION APPEARS TO BE
AT KBHK AND KMLS AND SOUTH THIS AFTERNOON/EVENING. POST FRONTAL
WINDS WILL BE STRONGER THAT FELT IN RECENT DAYS AND WILL TURN
NORTHERLY. GUSTS TO NEAR 20 KTS ARE EXPECTED AT ALL TERMINALS. VFR
CONDITIONS WILL PREVAIL...BUT VISIBILITIES WILL BE REDUCED IN AND
AROUND ANY SHOWER AND THUNDERSTORM ACTIVITY. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 083 059/087 060/089 060/093 061/090 059/089 058/087
2/T 20/B 01/B 12/T 23/T 33/T 32/T
LVM 081 052/087 053/090 054/092 055/090 054/087 052/084
3/T 21/U 11/B 12/T 24/T 43/T 32/T
HDN 085 057/089 058/091 061/093 062/093 061/091 058/090
2/T 20/B 01/B 12/T 23/T 33/T 32/T
MLS 086 059/086 060/089 063/092 064/093 063/089 061/090
4/T 20/U 00/U 02/T 23/T 33/T 32/T
4BQ 086 057/086 058/090 061/093 063/094 062/090 060/088
3/T 31/U 00/U 12/T 23/T 33/T 32/T
BHK 083 054/081 054/085 059/088 062/088 061/084 057/086
4/T 41/U 01/U 12/T 22/T 33/T 32/T
SHR 081 053/085 054/089 057/092 058/091 057/087 055/087
3/T 21/B 11/B 12/T 23/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
618 AM MDT SAT AUG 9 2014
.UPDATE...
WE MADE A MINOR FORECAST UPDATE TO INCLUDE PATCHY FOG UNTIL 15 UTC
ACROSS FALLON AND CARTER COUNTIES WITH LIGHT FOG BEING REPORTED AT
BAKER AS OF 12 UTC. YESTERDAY/S FOG LIFTED BY ABOUT 14 UTC OR 8 AM
MDT AND AND THE OVERALL SITUATION IS SIMILAR...SO WE EXPECT FOG TO
AGAIN BURN OFF QUICKLY IN THE NEXT TWO HOURS OR SO. SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND SUN...
A COLD FRONT WILL CROSS THE AREA TODAY WITH SOME CHANCE OF SHOWERS
AND STORMS...THOUGH NEITHER THE FRONTAL PASSAGE OR CONVECTION WILL
PROBABLY BE ANYTHING TO WRITE HOME ABOUT.
TODAY...THE SURFACE COLD FRONT WHICH HAS PASSED THROUGH BOTH HAVRE
AND GREAT FALLS AS OF 09 UTC WILL CONTINUE MOVING SOUTHEAST THANKS
TO THE PASSAGE OF A 500-MB SHORTWAVE TROUGH. THERE ARE 3 MB/3 HOUR
SURFACE PRESSURE RISES BEHIND THE FRONT AT 09 UTC AND WEAK SHOWERS
AND STORMS HAVE BEEN GOING ON OVERNIGHT IN NORTH CENTRAL MT...BOTH
OF WHICH MAY SIGNAL A BIT BETTER FRONTAL PUSH AND STRONGER COOLING
IN ITS WAKE THAN GUIDANCE SUGGESTS. WE THUS REDUCED HIGHS SOMEWHAT
TODAY AND PUSHED POST-FRONTAL WIND SPEEDS HIGHER THAN MOS GUIDANCE
ALONE WOULD SUGGEST. BOTH OF THOSE ADJUSTMENTS MIGHT NOT HAVE BEEN
ENOUGH...BUT THE CORE OF HEIGHT FALLS WITH THE SHORTWAVE WILL STAY
IN CANADA AND 850-MB COLD AIR ADVECTION IS NOT VERY ROBUST LIKE WE
TYPICALLY SEE IN CASES WHERE GUIDANCE UNDERDOES FRONTAL SURGES. IT
THUS SEEMED APPROPRIATE TO NOT SWING TOO HARD IN ANY ONE DIRECTION
WITH THE GRIDDED FORECAST UNTIL MESOSCALE TRENDS ARE SOLIDIFIED.
WHERE SHOWERS AND STORMS ARE CONCERNED...SHORT-RANGE GUIDANCE LIKE
THE 06 UTC HRRR TAKES THE SHOWERS AROUND HARLOWTON AT 09 UTC EAST-
SOUTHEAST THIS MORNING. BY AFTERNOON...THE FRONTAL ZONE WILL BE IN
SOUTHEASTERN MT AND SHOULD SERVE TO INCITE SHOWERS AND STORMS ON A
MORE SCATTERED BASIS FROM MILES CITY AND BROADUS EAST TO BAKER AND
EKALAKA. FORECAST SOUNDINGS IN THOSE AREAS SHOW MLCAPE AROUND 1200
J/KG...BUT 0-6-KM BULK SHEAR OF 20 KT...SUGGESTIVE OF SOME LOCALLY
HEAVY RAIN AND BRIEF STRONG STORMS...BUT VERY LOW SEVERE RISK. THE
00 UTC SPC SSEO IS ON BOARD WITH THIS IDEA WITH THE STORM COVERAGE
GREATEST IN FALLON AND CARTER COUNTIES FROM 21 TO 00 UTC. THE SSEO
AND IN PARTICULAR THE OFTEN-WELL-PERFORMING NSSL WRF-ARW /WHICH IS
A COMPONENT OF THE SSEO/ ALSO SUPPORTS ISOLATED TO MAYBE SCATTERED
SHOWERS AND STORMS OVER THE REST OF THE AREA THIS AFTERNOON TOO.
TONIGHT...SOME CONVECTION MAY LINGER INTO THE EVENING...BUT SHOULD
LARGELY DIMINISH BY 03 UTC AS FORCING SHIFTS INTO ND AND THE LOWER
ATMOSPHERE STABILIZES IN ITS WAKE. BOTH THE 00 UTC SPC SSEO OUTPUT
AND CONVECTIVELY-PARAMETERIZED GFS AND ECMWF SOLUTIONS SUPPORTED A
DRY FORECAST IN MANY AREAS AFTER 03 UTC /9 PM MDT/.
SUN...HIGHS WILL WARM BACK UP WELL INTO THE MID AND UPPER 80S F IN
MOST AREAS UNDER HEIGHT RISES ALOFT. WE RAISED FORECAST HIGHS SOME
5 TO 8 F USING THE 00 UTC MULTI-MODEL CONSENSUS...BUT THE FORECAST
STILL LAGS THE WARMER BIAS-CORRECTED GUIDANCE A BIT. WE EXPECT ANY
CONVECTION TO BE ISOLATED AND CONFINED TO NEAR THE HIGH TERRAIN AS
THE LARGE-SCALE HEIGHT RISES WILL PROVE DETRIMENTAL TO ACTIVITY IN
THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
UPPER LEVEL RIDGING ACROSS THE WESTERN PORTION OF THE US WILL
KEEP EARLY TO MID WEEK SURFACE TEMPERATURES IN THE LOW TO MID 90S
ACROSS SC AND SE MONTANA. HEIGHTS BEGIN TO LOWER BY WEDNESDAY AS
THE RIDGE BREAKS DOWN IN LIEU OF LOW PRESSURE MOVING IN OFF THE
COAST OF BRITISH COLUMBIA. MODELS DIFFER SOMEWHAT ON THE STRENGTH
OF THE LOW...BUT EITHER WAY CIRCULATION AROUND IT WILL BRING
SOUTHWESTERLY FLOW TO THE REGION BY THURSDAY. THIS WILL ALLOW A
CONDUIT FOR THE TAP OF SOME MONSOONAL MOISTURE FROM THE DESERT
SOUTHWEST AND BRING SOME POTENTIAL...MUCH NEEDED...PRECIPITATION
TO THE REGION. RAISED POPS ACCORDINGLY TO ACCOUNT FOR THIS.
NORTHWESTERLY FLOW WILL AGAIN DOMINATE BY NEXT WEEKEND...CUTTING
OFF THE POTENTIAL FOR ADDITIONAL PRECIPITATION. SINGER
&&
.AVIATION...
AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE TODAY AT ALL
TERMINALS WITH THE PASSAGE OF A SURFACE COLD FRONT. MODEL GUIDANCE
IS INDICATING THE BEST CHANCE OF PRECIPITATION MAY BE AT KBHK AND
KMLS THIS AFTERNOON. WINDS WILL BE SOMEWHAT STRONG AND NORTHERLY
POST FRONTAL...GUSTING TO NEAR 20 KTS AT ALL TERMINALS.
VISIBILITIES WILL BE REDUCED IN AND AROUND ANY SHOWER AND
THUNDERSTORM ACTIVITY. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 084 059/087 060/089 060/093 061/090 059/089 058/087
3/T 20/B 01/B 12/T 23/T 33/T 32/T
LVM 083 052/087 053/090 054/092 055/090 054/087 052/084
3/T 21/U 11/B 12/T 24/T 43/T 32/T
HDN 086 057/089 058/091 061/093 062/093 061/091 058/090
3/T 20/B 01/B 12/T 23/T 33/T 32/T
MLS 086 059/086 060/089 063/092 064/093 063/089 061/090
4/T 20/U 00/U 02/T 23/T 33/T 32/T
4BQ 087 057/086 058/090 061/093 063/094 062/090 060/088
3/T 31/U 00/U 12/T 23/T 33/T 32/T
BHK 084 054/081 054/085 059/088 062/088 061/084 057/086
4/T 41/U 01/U 12/T 22/T 33/T 32/T
SHR 083 053/085 054/089 057/092 058/091 057/087 055/087
3/T 21/B 11/B 12/T 23/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
313 AM MDT SAT AUG 9 2014
.SHORT TERM...VALID FOR TDY AND SUN...
A COLD FRONT WILL CROSS THE AREA TODAY WITH SOME CHANCE OF SHOWERS
AND STORMS...THOUGH NEITHER THE FRONTAL PASSAGE OR CONVECTION WILL
PROBABLY BE ANYTHING TO WRITE HOME ABOUT.
TODAY...THE SURFACE COLD FRONT WHICH HAS PASSED THROUGH BOTH HAVRE
AND GREAT FALLS AS OF 09 UTC WILL CONTINUE MOVING SOUTHEAST THANKS
TO THE PASSAGE OF A 500-MB SHORTWAVE TROUGH. THERE ARE 3 MB/3 HOUR
SURFACE PRESSURE RISES BEHIND THE FRONT AT 09 UTC AND WEAK SHOWERS
AND STORMS HAVE BEEN GOING ON OVERNIGHT IN NORTH CENTRAL MT...BOTH
OF WHICH MAY SIGNAL A BIT BETTER FRONTAL PUSH AND STRONGER COOLING
IN ITS WAKE THAN GUIDANCE SUGGESTS. WE THUS REDUCED HIGHS SOMEWHAT
TODAY AND PUSHED POST-FRONTAL WIND SPEEDS HIGHER THAN MOS GUIDANCE
ALONE WOULD SUGGEST. BOTH OF THOSE ADJUSTMENTS MIGHT NOT HAVE BEEN
ENOUGH...BUT THE CORE OF HEIGHT FALLS WITH THE SHORTWAVE WILL STAY
IN CANADA AND 850-MB COLD AIR ADVECTION IS NOT VERY ROBUST LIKE WE
TYPICALLY SEE IN CASES WHERE GUIDANCE UNDERDOES FRONTAL SURGES. IT
THUS SEEMED APPROPRIATE TO NOT SWING TOO HARD IN ANY ONE DIRECTION
WITH THE GRIDDED FORECAST UNTIL MESOSCALE TRENDS ARE SOLIDIFIED.
WHERE SHOWERS AND STORMS ARE CONCERNED...SHORT-RANGE GUIDANCE LIKE
THE 06 UTC HRRR TAKES THE SHOWERS AROUND HARLOWTON AT 09 UTC EAST-
SOUTHEAST THIS MORNING. BY AFTERNOON...THE FRONTAL ZONE WILL BE IN
SOUTHEASTERN MT AND SHOULD SERVE TO INCITE SHOWERS AND STORMS ON A
MORE SCATTERED BASIS FROM MILES CITY AND BROADUS EAST TO BAKER AND
EKALAKA. FORECAST SOUNDINGS IN THOSE AREAS SHOW MLCAPE AROUND 1200
J/KG...BUT 0-6-KM BULK SHEAR OF 20 KT...SUGGESTIVE OF SOME LOCALLY
HEAVY RAIN AND BRIEF STRONG STORMS...BUT VERY LOW SEVERE RISK. THE
00 UTC SPC SSEO IS ON BOARD WITH THIS IDEA WITH THE STORM COVERAGE
GREATEST IN FALLON AND CARTER COUNTIES FROM 21 TO 00 UTC. THE SSEO
AND IN PARTICULAR THE OFTEN-WELL-PERFORMING NSSL WRF-ARW /WHICH IS
A COMPONENT OF THE SSEO/ ALSO SUPPORTS ISOLATED TO MAYBE SCATTERED
SHOWERS AND STORMS OVER THE REST OF THE AREA THIS AFTERNOON TOO.
TONIGHT...SOME CONVECTION MAY LINGER INTO THE EVENING...BUT SHOULD
LARGELY DIMINISH BY 03 UTC AS FORCING SHIFTS INTO ND AND THE LOWER
ATMOSPHERE STABILIZES IN ITS WAKE. BOTH THE 00 UTC SPC SSEO OUTPUT
AND CONVECTIVELY-PARAMETERIZED GFS AND ECMWF SOLUTIONS SUPPORTED A
DRY FORECAST IN MANY AREAS AFTER 03 UTC /9 PM MDT/.
SUN...HIGHS WILL WARM BACK UP WELL INTO THE MID AND UPPER 80S F IN
MOST AREAS UNDER HEIGHT RISES ALOFT. WE RAISED FORECAST HIGHS SOME
5 TO 8 F USING THE 00 UTC MULTI-MODEL CONSENSUS...BUT THE FORECAST
STILL LAGS THE WARMER BIAS-CORRECTED GUIDANCE A BIT. WE EXPECT ANY
CONVECTION TO BE ISOLATED AND CONFINED TO NEAR THE HIGH TERRAIN AS
THE LARGE-SCALE HEIGHT RISES WILL PROVE DETRIMENTAL TO ACTIVITY IN
THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
UPPER LEVEL RIDGING ACROSS THE WESTERN PORTION OF THE US WILL
KEEP EARLY TO MID WEEK SURFACE TEMPERATURES IN THE LOW TO MID 90S
ACROSS SC AND SE MONTANA. HEIGHTS BEGIN TO LOWER BY WEDNESDAY AS
THE RIDGE BREAKS DOWN IN LIEU OF LOW PRESSURE MOVING IN OFF THE
COAST OF BRITISH COLUMBIA. MODELS DIFFER SOMEWHAT ON THE STRENGTH
OF THE LOW...BUT EITHER WAY CIRCULATION AROUND IT WILL BRING
SOUTHWESTERLY FLOW TO THE REGION BY THURSDAY. THIS WILL ALLOW A
CONDUIT FOR THE TAP OF SOME MONSOONAL MOISTURE FROM THE DESERT
SOUTHWEST AND BRING SOME POTENTIAL...MUCH NEEDED...PRECIPITATION
TO THE REGION. RAISED POPS ACCORDINGLY TO ACCOUNT FOR THIS.
NORTHWESTERLY FLOW WILL AGAIN DOMINATE BY NEXT WEEKEND...CUTTING
OFF THE POTENTIAL FOR ADDITIONAL PRECIPITATION. SINGER
&&
.AVIATION...
AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE TODAY AT ALL
TERMINALS WITH THE PASSAGE OF A SURFACE COLD FRONT. MODEL GUIDANCE
IS INDICATING THE BEST CHANCE OF PRECIPITATION MAY BE AT KBHK AND
KMLS THIS AFTERNOON. WINDS WILL BE SOMEWHAT STRONG AND NORTHERLY
POST FRONTAL...GUSTING TO NEAR 20 KTS AT ALL TERMINALS.
VISIBILITIES WILL BE REDUCED IN AND AROUND ANY SHOWER AND
THUNDERSTORM ACTIVITY. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 084 059/087 060/089 060/093 061/090 059/089 058/087
3/T 20/B 01/B 12/T 23/T 33/T 32/T
LVM 083 052/087 053/090 054/092 055/090 054/087 052/084
3/T 21/U 11/B 12/T 24/T 43/T 32/T
HDN 086 057/089 058/091 061/093 062/093 061/091 058/090
3/T 20/B 01/B 12/T 23/T 33/T 32/T
MLS 086 059/086 060/089 063/092 064/093 063/089 061/090
4/T 20/U 00/U 02/T 23/T 33/T 32/T
4BQ 087 057/086 058/090 061/093 063/094 062/090 060/088
3/T 31/U 00/U 12/T 23/T 33/T 32/T
BHK 084 054/081 054/085 059/088 062/088 061/084 057/086
4/T 41/U 01/U 12/T 22/T 33/T 32/T
SHR 083 053/085 054/089 057/092 058/091 057/087 055/087
3/T 21/B 11/B 12/T 23/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
140 PM EDT SAT AUG 9 2014
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL WAVER ACROSS THE AREA THROUGH
THE WEEKEND...WHILE LOW PRESSURE DEVELOPS ALONG THIS BOUNDARY
THEN MOVES OFFSHORE MONDAY. THIS WILL BRING AN EXTENDED PERIOD OF
UNSETTLED WEATHER...WITH WIDESPREAD SHOWERS AND PERIODS OF HEAVY
RAIN. THIS FRONT WILL MOVE OFFSHORE MONDAY NIGHT...BUT PERIODS OF
SHOWERS WILL CONTINUE THROUGH MID-WEEK. A STRONGER COLD FRONT WILL
CROSS OFFSHORE THURSDAY...BRINGING COOLER AND DRIER WEATHER INTO
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...WITH BREAKS OF SUNSHINE OVER SRN ZONES THE
WARM FRONT SHOULD START MOVING NORTHWARD...PERHAPS EVEN MAKING A FEW
DISCONTINUOUS JUMPS. DESTABILIZATION WILL SPREAD SOUTH TO NORTH
ACROSS THE FORECAST AREA ALTHOUGH THICK CLOUD COVER MAY INHIBIT THIS
PROCESS OVER NRN ZONES. MID AND UPPER LEVEL ASCENT PRETTY LACKING
BUT SWRLY LL FLOW TO ENCOUNTER THE SURFACE BOUNDARY LEADING TO CONVG
AND OVERRUNNING (AS ILLUSTRATED IN OUR FACEBOOK GRAPHIC THIS
MORNING). ANOTHER FACTOR THAT WILL CONTRIBUTE TO INCREASING RAIN
CHANCES AS THE DAY WEARS ON IS THE FACT THAT THE LEVEL OF FREE
CONVECTION WILL DROP BELOW 3 FT TODAY...WELL WITHIN THE DEPTH OF THE
MIXED LAYER. NO CHANGES THEN TO THE OVERALL FORECAST THINKING AND
ANY FORECAST ADJUSTMENTS LIKELY TO BE MINIMAL. SPC HIGHLIGHTS
AFOREMENTIONED SRN ZONES FOR LOW PROB WET MICROBURSTS GIVEN THE
EXTRA INSOLATION/INSTABILITY. RUC ANALYSIS ALREADY SHOWING A SMALL
TONGUE OF 2000+ J/KG OF SBCAPE OVER FAR SRN ZONES SO THIS SEEMS
PLAUSIBLE. SHOULD THESE AREAS CONTINUE TO SEE GOOD HEATING THEN SOME
DAMAGING WIND GUSTS MAY BE ADDED TO THE FORECAST. HEAVY RAIN REMAINS
BY FAR THE BIGGEST POTENTIAL HAZARD FOR THE DAY AS WELL AS INTO THE
OVERNIGHT HOURS WITH FREEZING LEVEL AOB 15KFT LEADING TO DEEP LAYER
WARM RAIN GENERATION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...IN WHAT HAS BECOME REPETITIVE THIS
SUMMER...ANOTHER EXTENDED PERIOD OF UNSETTLED WEATHER WILL DEVELOP
ACROSS THE EAST AS RENEWED TROUGHING FORMS OVER THE EASTERN CONUS.
THIS TROUGH WILL BE SLOW TO DEVELOP DURING THE SHORT TERM...BUT MUCH
LOWERED HEIGHTS WILL DROP SOUTH BY THE END OF THE PERIOD. AT THE
SURFACE...A STALLED COLD FRONT WILL WAVER IN THE
VICINITY...PROVIDING NOT ONLY A FOCUS FOR SURFACE CONVERGENCE AND
INCREASED SHOWER POTENTIAL...BUT A BAROCLINIC BOUNDARY ON WHICH LOW
PRESSURE WILL DEVELOP AND MOVE EAST THROUGH THE PERIOD.
AS TROUGHING DEVELOPS ALOFT...WINDS WILL BECOME MORE SWLY...WHICH
COMBINED WITH THE S/SE SURFACE WINDS WILL DRIVE PWATS WELL ABOVE 2
INCHES...TOWARDS 2.3 INCHES...WHICH APPROACHES +2 SD`S FOR
MID-AUGUST. THIS ALSO DRIVES STRENGTHENING ISENTROPIC LIFT ATOP THE
AFOREMENTIONED FRONT...WHICH HELPS TO SQUEEZE OUT THE DEEP MOISTURE
CONTENT OF THE COLUMN. COMBINE THIS WITH IMPULSES MOVING OVERHEAD
THE FRONT...SPAWNING LOW PRESSURE DEVELOPMENT...AND THE ENTIRE SHORT
TERM LOOKS TO BE SOMEWHAT OF A WASH-OUT. SREF PLUMES RANGE FROM 1 TO
AS MUCH AS 6 INCHES OF QPF DURING THIS 48-HR PERIOD...WITH THE
ENSEMBLE MEAN AROUND 2.5 INCHES. THE STRONGEST LIFT WILL BE ACROSS
THE NORTHERN HALF OF THE CWA...BUT THE ENTIRETY OF THE CWA IS LIKELY
TO SEE PERIODS OF HEAVY RAINFALL...AND CATEGORICAL POP WILL BE
INTRODUCED EVERYWHERE...DRYING OUT ONLY BY MONDAY NIGHT AS THE
FRONT CROSSES OFFSHORE AS A COLD FRONT BEHIND THE SURFACE LOW
PRESSURE. THE EXPECTED HEAVY RAINFALL ON TOP OF WHAT HAS BEEN A
WET FEW WEEKS LOCALLY WILL LIKELY CAUSE SOME FLOODING PROBLEMS
ACROSS THE AREA...AND A FLOOD WATCH MAY BE NEEDED AT SOME POINT
DURING THE PERIOD. FOR NOW...WILL HANDLE WITH SOME ENHANCED
WORDING IN THE HWO.
CLOUDS...RAIN...AND A WEAK WEDGE WILL KEEP TEMPS WELL BELOW CLIMO
NORMS ON SUNDAY...WITH UPPER 70S EXPECTED IN THE FAR NORTHERN
TIER...TO LOW 80S DOWN SOUTH. TEMPS MONDAY WILL BE ONLY SLIGHTLY
WARMER. MINS BOTH NIGHTS WILL BE JUST AROUND OR EVEN ABOVE NORMAL
HOWEVER...AS MINIMAL DIURNAL RANGES OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...LARGE UPPER TROUGH ACROSS THE EAST WILL
PLAGUE THE REGION FOR THE FIRST HALF OF THE EXTENDED...BUT A RETURN
TO DRIER AND MORE SEASONABLE WEATHER IS EXPECTED LATE WEEK.
COLD FRONT JUST OFFSHORE AT THE START OF THE PERIOD WILL DRY THE
REGION OUT FROM A VERY WET MONDAY...BUT THIS WILL BE SHORT LIVED AS
IMPULSES WITHIN THE LONGWAVE TROUGH AND A RETURN OF SW COLUMN FLOW
WILL INCREASE COLUMN MOISTURE ONCE AGAIN. TUE/WED WILL NOT BE AS
UNSETTLED OR WET AS EARLY IN THE WEEK...BUT AT LEAST SCT CONVECTION
WITH ABOVE-CLIMO POP ANTICIPATED TUESDAY...WITH TYPICAL DIURNAL
COVERAGE ON WEDNESDAY. A STRONGER COLD FRONT WILL CROSS THE AREA BY
THURSDAY MORNING...PUSHED QUICKLY OFFSHORE BY THE 500MB VORTEX
CENTER MOVING NE INTO CANADA. THIS LEAVES MORE DRY WESTERLY FLOW IN
THE MID-LEVELS AS THE TROUGH RECEDES BACK TO THE NORTH AND SOUTHERN
HIGH PRESSURE RIDGE EXPANDS ZONALLY THROUGH THE END OF THE WEEK.
TEMPS DURING THE EXTENDED WILL BE RIGHT AROUND CLIMO VALUES FOR
HIGHS...WITH WEDNESDAY LIKELY THE WARMEST...AND THE ONE MOST LIKELY
TO FEATURE WIDESPREAD 90 DEGREE READINGS FOR HIGHS. MINS WILL BE
WELL ABOVE CLIMO EARLY IN THE PERIOD THANKS TO SW FLOW AND CLOUD
COVER...BEFORE DROPPING TO SLIGHTLY BELOW NORMAL BEHIND THE COLD
FRONT LATE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...AS OF 18Z...SHRA/TSRA WITH MVFR/BRIEF IFR TO MOVE FROM
KFLO/KLBT TO THE COASTAL TERMINALS BY MID AFTERNOON. A BRIEF LULL IN
HEAVY PRECIPITATION/TS WILL DEVELOP FROM NW-SE LATE THIS AFTERNOON
INTO THIS EVENING...BUT ANOTHER IMPULSE WILL DEVELOP A WAVE ON THE
WEAK FRONT TO THE SOUTH WITH THE BEST POTENTIAL FOR TSRA AT THE
SOUTHERN TERMINALS OVERNIGHT. THIS SHOULD END W-E AROUND DAYBREAK.
TEMPO IFR CONDITIONS MORE LIKELY OVERNIGHT. FLIGHT CONDITIONS
IMPROVING TO MVFR AFTER DAYBREAK...BUT THERE WILL REMAIN A POTENTIAL
FOR LIGHT RAIN THROUGH THE MORNING AT ALL TERMINALS.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...NO CHANGES TO THE FORECAST OR FORECAST
REASONING. THE PREVIOUS DISCUSSION STILL APPLIES...
AS OF 615 AM SATURDAY...NO ADVISORIES OR CAUTION STATEMENTS NEEDED
TODAY BUT SEA CONDITIONS WILL BE A BUMPY 3-4 FEET AS E-SE WINDS
PREVAIL AND INCREASE A BIT INTO TONIGHT. COMPLICATING MARINE WX IS
THE POTENTIAL FOR TSTMS ON THE WATERS AND MARINERS SHOULD CONSIDER
KEEP ALERT TO RADAR TRENDS TODAY. PLENTIFUL MOISTURE IN THE
ATMOSPHERE LATER TODAY AND TONIGHT COULD REDUCE VSBYS ION HEAVY
RAIN TO BELOW 1NM AT TIMES. THE SEAS SPECTRUM WILL FEATURES A MIX
OF SE WAVES 1-1.5 FEET EVERY 8-9 SECONDS AND E-ESE WAVES OF 2-3
FEET EVERY 4-5 SECONDS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...A MEANDERING FRONT AND DEVELOPING LOW
PRESSURE WILL IMPACT THE WATERS THIS PERIOD...CAUSING WINDS TO SHIFT
THROUGH NEARLY THE ENTIRETY OF COMPASS DIRECTIONS. SE WINDS
INITIALLY AROUND 10 KTS WILL BACK TO THE S/SW AS THE LOW PRESSURE
MOVES CLOSER SUNDAY NIGHT INTO MONDAY. A PERIOD OF LIGHT AND
VARIABLE WINDS IS EXPECTED LATE MONDAY AS THE LOW MOVES DIRECTLY
OVER THE WATERS...BUT THE TRAILING COLD FRONT WHICH CROSSES MONDAY
NIGHT WILL THEN TURN WINDS TO THE W/NW AROUND 10 KTS MONDAY NIGHT.
WAVE HEIGHTS WILL BE 2-3 FT THROUGH THE PERIOD WITH A SE GROUND
SWELL AND SOUTHERLY WIND WAVE CREATING THE WAVE SPECTRUM. NEAR SHORE
SEAS WILL BE HIGHER ON SUNDAY THANKS TO THE MORE SIGNIFICANT ONSHORE
WAVE DIRECTION THAN WHAT WILL EXIST ON MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...WEAK COLD FRONT OFFSHORE TO START TUESDAY
WILL LEAVE A BRIEF PERIOD OF W/NW WINDS ACROSS THE WATERS...BUT HIGH
PRESSURE WILL RE-ASSERT ITSELF OFFSHORE THROUGH MID-WEEK CREATING A
RETURN TO PREDOMINANT SW FLOW. SW WINDS WILL BECOME 10-15 KTS BY
TUESDAY AFTN...AND THEN SLOWLY RISE TO 15-20 KTS LATE WEDNESDAY
AHEAD OF A STRONGER COLD FRONT PROGGED TO CROSS LATE IN THE PERIOD.
SEAS OF 2-4 FT WILL BE COMMON THROUGH MID-WEEK...WITH THE INCREASED
SW WINDS CAUSING A SHORTER AVERAGE WAVE PERIOD AND STEEPER FACES
THAN EARLIER IN THE WEEK.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 AM SATURDAY...A COASTAL FLOOD ADVISORY WILL BE NEEDED TO
ADDRESS A STRONG ASTRONOMICAL TIDE PRESENTLY...AND NOT ONLY FOR
DOWNTOWN BUT ALSO AREA BEACHES WHERE HIGH-WATER RUN-UP IS LIKELY.
THIS ADVISORY WILL NOT BE NEEDED FOR THE NEXT HIGH TIDE CYCLE THIS
MORNING...BUT FOR THE HIGH TIDE THIS EVENING...HIGHER OF TODAYS
HIGH TIDES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...COASTAL FLOOD ADVISORY FROM 6 PM TO 9 PM EDT THIS EVENING FOR
SCZ054-056.
NC...COASTAL FLOOD ADVISORY FROM 6 PM TO 9 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MBB/MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 AM EDT SAT AUG 9 2014
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL WAVER ACROSS THE AREA THROUGH
THE WEEKEND...WHILE LOW PRESSURE DEVELOPS ALONG THIS BOUNDARY
THEN MOVES OFFSHORE MONDAY. THIS WILL BRING AN EXTENDED PERIOD OF
UNSETTLED WEATHER...WITH WIDESPREAD SHOWERS AND PERIODS OF HEAVY
RAIN. THIS FRONT WILL MOVE OFFSHORE MONDAY NIGHT...BUT PERIODS OF
SHOWERS WILL CONTINUE THROUGH MID-WEEK. A STRONGER COLD FRONT WILL
CROSS OFFSHORE THURSDAY...BRINGING COOLER AND DRIER WEATHER INTO
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...WITH BREAKS OF SUNSHINE OVER SRN ZONES THE
WARM FRONT SHOULD START MOVING NORTHWARD...PERHAPS EVEN MAKING A FEW
DISCONTINUOUS JUMPS. DESTABILIZATION WILL SPREAD SOUTH TO NORTH
ACROSS THE FORECAST AREA ALTHOUGH THICK CLOUD COVER MAY INHIBIT THIS
PROCESS OVER NRN ZONES. MID AND UPPER LEVEL ASCENT PRETTY LACKING
BUT SWRLY LL FLOW TO ENCOUNTER THE SURFACE BOUNDARY LEADING TO CONVG
AND OVERRUNNING (AS ILLUSTRATED IN OUR FACEBOOK GRAPHIC THIS
MORNING). ANOTHER FACTOR THAT WILL CONTRIBUTE TO INCREASING RAIN
CHANCES AS THE DAY WEARS ON IS THE FACT THAT THE LEVEL OF FREE
CONVECTION WILL DROP BELOW 3 FT TODAY...WELL WITHIN THE DEPTH OF THE
MIXED LAYER. NO CHANGES THEN TO THE OVERALL FORECAST THINKING AND
ANY FORECAST ADJUSTMENTS LIKELY TO BE MINIMAL. SPC HIGHLIGHTS
AFOREMENTIONED SRN ZONES FOR LOW PROB WET MICROBURSTS GIVEN THE
EXTRA INSOLATION/INSTABILITY. RUC ANALYSIS ALREADY SHOWING A SMALL
TONGUE OF 2000+ J/KG OF SBCAPE OVER FAR SRN ZONES SO THIS SEEMS
PLAUSIBLE. SHOULD THESE AREAS CONTINUE TO SEE GOOD HEATING THEN SOME
DAMAGING WIND GUSTS MAY BE ADDED TO THE FORECAST. HEAVY RAIN REMAINS
BY FAR THE BIGGEST POTENTIAL HAZARD FOR THE DAY AS WELL AS INTO THE
OVERNIGHT HOURS WITH FREEZING LEVEL AOB 15KFT LEADING TO DEEP LAYER
WARM RAIN GENERATION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...IN WHAT HAS BECOME REPETITIVE THIS
SUMMER...ANOTHER EXTENDED PERIOD OF UNSETTLED WEATHER WILL DEVELOP
ACROSS THE EAST AS RENEWED TROUGHING FORMS OVER THE EASTERN CONUS.
THIS TROUGH WILL BE SLOW TO DEVELOP DURING THE SHORT TERM...BUT MUCH
LOWERED HEIGHTS WILL DROP SOUTH BY THE END OF THE PERIOD. AT THE
SURFACE...A STALLED COLD FRONT WILL WAVER IN THE
VICINITY...PROVIDING NOT ONLY A FOCUS FOR SURFACE CONVERGENCE AND
INCREASED SHOWER POTENTIAL...BUT A BAROCLINIC BOUNDARY ON WHICH LOW
PRESSURE WILL DEVELOP AND MOVE EAST THROUGH THE PERIOD.
AS TROUGHING DEVELOPS ALOFT...WINDS WILL BECOME MORE SWLY...WHICH
COMBINED WITH THE S/SE SURFACE WINDS WILL DRIVE PWATS WELL ABOVE 2
INCHES...TOWARDS 2.3 INCHES...WHICH APPROACHES +2 SD`S FOR
MID-AUGUST. THIS ALSO DRIVES STRENGTHENING ISENTROPIC LIFT ATOP THE
AFOREMENTIONED FRONT...WHICH HELPS TO SQUEEZE OUT THE DEEP MOISTURE
CONTENT OF THE COLUMN. COMBINE THIS WITH IMPULSES MOVING OVERHEAD
THE FRONT...SPAWNING LOW PRESSURE DEVELOPMENT...AND THE ENTIRE SHORT
TERM LOOKS TO BE SOMEWHAT OF A WASH-OUT. SREF PLUMES RANGE FROM 1 TO
AS MUCH AS 6 INCHES OF QPF DURING THIS 48-HR PERIOD...WITH THE
ENSEMBLE MEAN AROUND 2.5 INCHES. THE STRONGEST LIFT WILL BE ACROSS
THE NORTHERN HALF OF THE CWA...BUT THE ENTIRETY OF THE CWA IS LIKELY
TO SEE PERIODS OF HEAVY RAINFALL...AND CATEGORICAL POP WILL BE
INTRODUCED EVERYWHERE...DRYING OUT ONLY BY MONDAY NIGHT AS THE
FRONT CROSSES OFFSHORE AS A COLD FRONT BEHIND THE SURFACE LOW
PRESSURE. THE EXPECTED HEAVY RAINFALL ON TOP OF WHAT HAS BEEN A
WET FEW WEEKS LOCALLY WILL LIKELY CAUSE SOME FLOODING PROBLEMS
ACROSS THE AREA...AND A FLOOD WATCH MAY BE NEEDED AT SOME POINT
DURING THE PERIOD. FOR NOW...WILL HANDLE WITH SOME ENHANCED
WORDING IN THE HWO.
CLOUDS...RAIN...AND A WEAK WEDGE WILL KEEP TEMPS WELL BELOW CLIMO
NORMS ON SUNDAY...WITH UPPER 70S EXPECTED IN THE FAR NORTHERN
TIER...TO LOW 80S DOWN SOUTH. TEMPS MONDAY WILL BE ONLY SLIGHTLY
WARMER. MINS BOTH NIGHTS WILL BE JUST AROUND OR EVEN ABOVE NORMAL
HOWEVER...AS MINIMAL DIURNAL RANGES OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...LARGE UPPER TROUGH ACROSS THE EAST WILL
PLAGUE THE REGION FOR THE FIRST HALF OF THE EXTENDED...BUT A RETURN
TO DRIER AND MORE SEASONABLE WEATHER IS EXPECTED LATE WEEK.
COLD FRONT JUST OFFSHORE AT THE START OF THE PERIOD WILL DRY THE
REGION OUT FROM A VERY WET MONDAY...BUT THIS WILL BE SHORT LIVED AS
IMPULSES WITHIN THE LONGWAVE TROUGH AND A RETURN OF SW COLUMN FLOW
WILL INCREASE COLUMN MOISTURE ONCE AGAIN. TUE/WED WILL NOT BE AS
UNSETTLED OR WET AS EARLY IN THE WEEK...BUT AT LEAST SCT CONVECTION
WITH ABOVE-CLIMO POP ANTICIPATED TUESDAY...WITH TYPICAL DIURNAL
COVERAGE ON WEDNESDAY. A STRONGER COLD FRONT WILL CROSS THE AREA BY
THURSDAY MORNING...PUSHED QUICKLY OFFSHORE BY THE 500MB VORTEX
CENTER MOVING NE INTO CANADA. THIS LEAVES MORE DRY WESTERLY FLOW IN
THE MID-LEVELS AS THE TROUGH RECEDES BACK TO THE NORTH AND SOUTHERN
HIGH PRESSURE RIDGE EXPANDS ZONALLY THROUGH THE END OF THE WEEK.
TEMPS DURING THE EXTENDED WILL BE RIGHT AROUND CLIMO VALUES FOR
HIGHS...WITH WEDNESDAY LIKELY THE WARMEST...AND THE ONE MOST LIKELY
TO FEATURE WIDESPREAD 90 DEGREE READINGS FOR HIGHS. MINS WILL BE
WELL ABOVE CLIMO EARLY IN THE PERIOD THANKS TO SW FLOW AND CLOUD
COVER...BEFORE DROPPING TO SLIGHTLY BELOW NORMAL BEHIND THE COLD
FRONT LATE WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...MVFR VSBYS IN BR AT KFLO/KLBT WILL IMPROVE TO VFR OVER
THE NEXT HOUR OR TWO. NE WINDS WILL VEER TO THE ESE AS THE MORNING
PROGRESSES. AN AREA OF SCATTERED MAINLY LIGHT SHOWERS WILL MOVE
ACROSS THE COASTAL TERMINALS EARLY THIS MORNING. AN AREA OF
SHRA/TSRA WILL MOVE INTO KFLO/KLBT 14-15Z. MVFR EXPECTED WITH THE
SHOWERS. BRIEF IFR IS POSSIBLE IN STRONGER CELLS NEAR KFLO/KLBT.
HEAVIEST OF THE PRECIPITATION SHOULD BE AT THE COAST BY AFTERNOON. A
BRIEF LULL IN PRECIPITATION WILL DEVELOP FROM KLBT-KILM EARLY THIS
EVENING...BUT ANOTHER IMPULSE WILL INCREASE AREAL COVERAGE SHRA/TSRA
THIS EVENING INTO THE OVERNIGHT.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...NO CHANGES TO THE FORECAST OR FORECAST
REASONING. THE PREVIOUS DISCUSSION STILL APPLIES...
AS OF 615 AM SATURDAY...NO ADVISORIES OR CAUTION STATEMENTS NEEDED
TODAY BUT SEA CONDITIONS WILL BE A BUMPY 3-4 FEET AS E-SE WINDS
PREVAIL AND INCREASE A BIT INTO TONIGHT. COMPLICATING MARINE WX IS
THE POTENTIAL FOR TSTMS ON THE WATERS AND MARINERS SHOULD CONSIDER
KEEP ALERT TO RADAR TRENDS TODAY. PLENTIFUL MOISTURE IN THE
ATMOSPHERE LATER TODAY AND TONIGHT COULD REDUCE VSBYS ION HEAVY
RAIN TO BELOW 1NM AT TIMES. THE SEAS SPECTRUM WILL FEATURES A MIX
OF SE WAVES 1-1.5 FEET EVERY 8-9 SECONDS AND E-ESE WAVES OF 2-3
FEET EVERY 4-5 SECONDS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...A MEANDERING FRONT AND DEVELOPING LOW
PRESSURE WILL IMPACT THE WATERS THIS PERIOD...CAUSING WINDS TO SHIFT
THROUGH NEARLY THE ENTIRETY OF COMPASS DIRECTIONS. SE WINDS
INITIALLY AROUND 10 KTS WILL BACK TO THE S/SW AS THE LOW PRESSURE
MOVES CLOSER SUNDAY NIGHT INTO MONDAY. A PERIOD OF LIGHT AND
VARIABLE WINDS IS EXPECTED LATE MONDAY AS THE LOW MOVES DIRECTLY
OVER THE WATERS...BUT THE TRAILING COLD FRONT WHICH CROSSES MONDAY
NIGHT WILL THEN TURN WINDS TO THE W/NW AROUND 10 KTS MONDAY NIGHT.
WAVE HEIGHTS WILL BE 2-3 FT THROUGH THE PERIOD WITH A SE GROUND
SWELL AND SOUTHERLY WIND WAVE CREATING THE WAVE SPECTRUM. NEAR SHORE
SEAS WILL BE HIGHER ON SUNDAY THANKS TO THE MORE SIGNIFICANT ONSHORE
WAVE DIRECTION THAN WHAT WILL EXIST ON MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...WEAK COLD FRONT OFFSHORE TO START TUESDAY
WILL LEAVE A BRIEF PERIOD OF W/NW WINDS ACROSS THE WATERS...BUT HIGH
PRESSURE WILL RE-ASSERT ITSELF OFFSHORE THROUGH MID-WEEK CREATING A
RETURN TO PREDOMINANT SW FLOW. SW WINDS WILL BECOME 10-15 KTS BY
TUESDAY AFTN...AND THEN SLOWLY RISE TO 15-20 KTS LATE WEDNESDAY
AHEAD OF A STRONGER COLD FRONT PROGGED TO CROSS LATE IN THE PERIOD.
SEAS OF 2-4 FT WILL BE COMMON THROUGH MID-WEEK...WITH THE INCREASED
SW WINDS CAUSING A SHORTER AVERAGE WAVE PERIOD AND STEEPER FACES
THAN EARLIER IN THE WEEK.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 AM SATURDAY...A COASTAL FLOOD ADVISORY WILL BE NEEDED TO
ADDRESS A STRONG ASTRONOMICAL TIDE PRESENTLY...AND NOT ONLY FOR
DOWNTOWN BUT ALSO AREA BEACHES WHERE HIGH-WATER RUN-UP IS LIKELY.
THIS ADVISORY WILL NOT BE NEEDED FOR THE NEXT HIGH TIDE CYCLE THIS
MORNING...BUT FOR THE HIGH TIDE THIS EVENING...HIGHER OF TODAYS
HIGH TIDES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...COASTAL FLOOD ADVISORY FROM 6 PM TO 9 PM EDT THIS EVENING FOR
SCZ054-056.
NC...COASTAL FLOOD ADVISORY FROM 6 PM TO 9 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MBB/MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EDT SAT AUG 9 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING WET WEATHER TO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OF THIS MORNING/...
AS OF 940 AM SATURDAY...
UPDATE...HEAVY RAIN ALONG THE SHEAR AXIS PARKED ACROSS THE NORTHEAST
HAS PRODUCED ESTIMATED 2+ INCHES...AND THE AXIS LOOKS TO PERSIST
THROUGH 17Z PER LATEST RAP MODEL RUN. AS SUCH...WILL INCREASE PRECIP
CHANCES TO 100 AND QPF TO A WIDESPREAD 3/4 INCH THROUGH 18Z
ACCOMPANIED BY A FLOOD ADVISORY. ELSEWHERE...ISENTROPIC UPGLIDE
CONTINUES WITH EXPECTATIONS OF INCREASING COVERAGE PER HRRR/RAP.
SINCE ONGOING POPS INCREASE TO 100 THIS AFTERNOON...NOT MUCH
ADJUSTMENT NEEDED. TEMPS HOLDING IN THE MID 60S ACROSS THE NORTHERN
TIER WON`T MAKE MID 70S AND WILL BE MAKING DOWNWARD ADJUSTMENTS.
PREVIOUS DISCUSSION...
TWO DISTINCT AREAS OF LIGHT RAIN ARE ONGOING ACROSS CENTRAL NC ATTM.
THE FIRST AREA ACROSS OUR NORTHERN AND FAR NORTHEAST ZONES...HAS
BEEN ONGOING MUCH OF THE OVERNIGHT AND EARLY MORNING HOURS AND
CONTINUES TO DRIFT FROM NW TO SE...DRIVEN IN PART BY A SHORT WAVE
TROUGH AND ASSOC SHEAR AXIS MOVING SE ACROSS VA. FARTHER SOUTH...
OVER THE PAST FEW HOURS ADDITIONAL RAIN HAS DEVELOPED FROM SW TOWARD
THE NE AS LOWER LEVEL ISENTROPIC UPGLIDE HAS HELPED LIFT...COOL...
AND SATURATE THE COLUMN WITH TIME. IN BOTH AREAS...RAINFALL AMOUNTS
ARE GENERALLY LIGHT. THE LATEST HRRR SHOWS THESE PROCESSES
CONTINUING THROUGH THE REST OF THE MORNING HOURS...WITH ADDITION
LIGHT RAIN CONTINUING OVER A GOOD PORTION OF CENTRAL NC. FOR THE
NEAR TERM UPDATE HAVE INCREASED POPS TO CATEGORICAL FOR THE MORNING
HOURS. TEMPS WILL BE SLOW TO RISE THIS MORNING WITH THE CLOUDS AND
RAIN...HOLDING IN THE LOWER 70S...PERHAPS GETTING INTO THE MID 70S
THIS AFTERNOON.
&&
.SHORT TERM /THIS AFTERNOON THROUGH SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...
NOT MUCH CHANGE IN THE FORECAST THINKING FROM PREV CYCLES...WITH
CLOUDY AND WET-AT-TIMES WEATHER FOR MUCH OF THIS WEEKEND...AS A
SERIES OF UPPER SHORT WAVES ARE PROGGED TO MOVE ACROSS OUR REGION
OVER TOP OF THE SFC BOUNDARY THAT IS PROGGED TO REMAIN SOMEWHERE
INVOF OF THE NC/SC BORDER. NORTH OF THIS BOUNDARY AND ACROSS THE
PIEDMONT...A HYBRID CAD PATTERN WILL PERSIST. THE MODELS RECENTLY
HAVE BEEN RATHER ROBUST WITH QPF VALUES...A CONSENSUS OF WHICH HAVE
GENERALLY BEEN PAINTING A PICTURE OF ANYWHERE BETWEEN 2 TO 4 (OR
MORE) INCHES OF RAIN ACROSS OUR CWA THIS WEEKEND...GENERALLY HIGHEST
WEST. WHILE ITS TOUGH TO PIN DOWN EXACTLY WHICH AREAS WILL RECEIVE
THE HEAVIEST RAIN AND WHAT THE FINAL TOTALS WILL BE...THE HEAVIEST
RAIN TODAY MAY END UP BEING CLOSER TO...AND JUST NORTH OF THE
BOUNDARY WHERE THE PRECIP WILL BE MORE CONVECTIVE IN NATURE...MUCH
LIKE THE CLUSTER OF RAIN SHOWERS THAT MOVED NORTH OUT OF NORTH-
CENTRAL SC A FEW HOURS AGO. WILL ALSO HAVE TO CLOSELY MONITOR THE
SHORT WAVE TROUGH NOW CROSSING THE CENTRAL PLAINS...AS MODELS SHOW
THIS WAVE MOVING SE AND INDUCING A WELL-DEFINED SFC LOW TO OUR SOUTH
ALONG THE AFOREMENTIONED BOUNDARY LATE SUNDAY AND SUNDAY NIGHT. THE
COMBINATION AND STRENGTHENING E/SE FLOW AHEAD OF THIS LOW...VIGOROUS
1000-850MB MOISTURE TRANSPORT ASSOC WITH THIS FLOW...AND ASCENT
OVERTOP THE WEDGE (ON THE N/NW SIDE OF THE SFC WAVE)...SHOULD RESULT
IN A PERIOD OF MODERATE TO HEAVY RAINFALL FROM LATE SUNDAY MORNING
LASTING THROUGH MUCH OF THE DAY SUNDAY AND PERHAPS INTO THE NIGHT-
TIME HOURS...WITH THE HEAVIEST RAIN ACROSS OUR PIEDMONT ZONES WHERE
CAD WILL BE DEEPER. THIS PERIOD OF TIME WILL LIKELY ACCOUNT FOR THE
BULK OF THE RAINFALL THAT WE GET WITH THIS SYSTEM.
IN TERMS OF IMPACTS...IF THE MODEL QPF IS CORRECT...THEN URBAN...
POOR DRAINAGE...AND SMALL CREEK FLOODING WOULD LIKELY BE A CONCERN
IN THE SHORTER TERM...THEN THE POTENTIAL FOR MINOR RIVER FLOODING IN
THE LONGER TERM. HOWEVER...THERE IS STILL A CONSIDERABLE AMOUNT OF
UNCERTAINLY AND LOWER-THAN-NORMAL CONFIDENCE IN THESE QPF VALUES...
ESP SINCE PRECIP HAS BEEN SOMEWHAT SLOWER TO DEVELOP SO FAR COMPARED
TO WHAT MODELS HAVE BEEN SUGGESTING. AS SUCH...WE PLAN TO HOLD OFF
ISSUING ANY FLOOD WATCHES ATTM...AND INSTEAD CONTINUE TO STRONGLY
WORD THE HWO. THEN IF THE PRECIP INDEED BEGINS TO DEVELOP AS MODELS
HAVE BEEN SUGGESTING...WE MAY NEED TO ISSUE A QUICK FLOOD WATCH FOR
THE AFOREMENTIONED CONCERNS.
OTHERWISE...GIVEN THE SFC BOUNDARY AND BEST INSTABILITY POSITIONED
TO OUR SOUTH...RIGHT NOW IT LOOKS LIKE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER OUR AREA WILL BE LOW DURING THIS WEEKEND.
TEMPS WILL BE A FUNCTION OF THE CLOUDS AND PRECIP...BUT OVERALL
EXPECTED TO RUN BELOW NORMAL FOR HIGHS (GENERALLY IN THE
70S...WARMEST SE) AND NEAR NORMAL FOR LOWS (MID-UPR 60S).
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
THE COLD AIR DAMMING AIRMASS WILL HOLD ON THROUGH
MONDAY...POTENTIALLY INTO TUESDAY...WHILE A MILLER TYPE-B LOW
PRESSURE MOVES SLOWLY ALONG THE STALLED FRONTAL ZONE OVER SC AND
EASTERN NC. THE UPPER LEVEL FLOW CONTINUES TO BE WEAK AND WEST-
NORTHWESTERLY WITH THE POTENTIAL FOR A FEW WEAK DISTURBANCES ALOFT.
AS THE SURFACE WAVE TRACKS NEAR FROM SC TOWARD THE NC COAST...THE
LOW-LEVEL FLOW OVER CENTRAL NC WEAKENS AND BACKS AROUND TO MORE EAST-
NORTH...REDUCING THE ISENTROPIC ACCENT OVER THE WEDGE AIRMASS.
THUS...THE PRIMARY FORCING SHOULD SHIFT TO THE ENHANCED LOW-LEVEL
CONVERGENCE OF NEAR THE SURFACE WAVE....AND PRECIP SHOULD BECOME
LESS WIDESPREAD/INTENSE. WILL MAINTAIN HIGHER POPS ACROSS THE
COASTAL PLAIN..BUT EXPECT PRECIP TO BECOME MORE DRIZZLY OVER THE
PIEDMONT. HIGHS WILL AGAIN BE WELL BELOW NORMAL AND NOT MUCH HIGHER
THAN SUNDAY...LOW/MID 70S NORTHWEST AND UPPER 70S SOUTHEAST. LOWS
MONDAY NIGHT IN THE UPPER 60S.
THE SURFACE WAVE WILL CONTINUE TO MOVE OFF TO THE NORTHEAST TUESDAY
WHILE THE PARENT LOW WEST OF THE MOUNTAINS LIFTS OFF TOWARD THE GREAT
LAKES. THE COLD FRONT ATTENDANT TO THE LOW SHOULD BE WHAT
ULTIMATELY CLEARS TO THE LINGERING WEDGE AIRMASS AND LOW CLOUDS
OUT...THOUGH SOME DRIER AIR ALOFT AHEAD OF THE FRONT MAY ALSO HELP.
IT IS POSSIBLE THAT THE LOW CLOUDS MAY THIN ON TUESDAY BUT NOT BE
COMPLETELY GONE UNTIL WEDNESDAY. WITHOUT BETTER DEEP FORCING
ACCOMPANYING THE FRONT OR A CHANCE FOR BETTER INSTABILITY...WILL
KEEP POPS IN THE CHANCE RANGE FOR TUESDAY INTO TUESDAY NIGHT. THE
COLD FRONT MAY BE VERY SLOW TO CLEAR THE AREA WEDNESDAY INTO
THURSDAY...AS DEPICTED BY THE GFS...BUT MUCH DRIER AIR THROUGH A
DEEP LAYER WILL BRING PRECIP CHANCES TO AN END BY WEEKS END...AS
ANOTHER UPPER TROUGH SETS UP OVER THE EASTERN US AND A DRY NORTHWEST
FLOW DOMINATES. THIS WILL ALSO LEAD TO TEMPS A CATEGORY OR SO BELOW
NORMAL...WITH HIGHS IN THE LOW/MID 80S AND LOWS IN THE LOW/MID 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
FOR THE 24 HOUR TAF PERIOD: OVER THE PAST FEW HOURS LIGHT RAIN HAS
STARTED TO FILL IN ACROSS CENTRAL NC...ESP EAST OF THE TRIAD REGION.
ASIDE FROM A FEW POCKETS OF HEAVIER RAIN...MOST OF THE RAIN IS
LIGHT. EVEN WITH THIS RAIN...FLT CONDITIONS REMAIN MOSTLY MVFR EAST
OF A LINE FROM KHNZ-KRDU-KRCZ. WEST OF THIS LINE WE`RE SEEING
NUMEROUS IFR CIGS AND VSBYS. REGIONAL RADAR TRENDS AND LATEST HRRR
SUGGEST THAT THE RAIN WILL CONTINUE TO EXPAND ACROSS MOST OF CENTRAL
NC THROUGH THE REST OF THE MORNING HOURS...WITH FLT CONDITIONS
FURTHER DETERIORATING EAST. THEREAFTER...EXPECT IFR TO LOW-MVFR
CONDITIONS THROUGH THE REST OF THE TAF PERIOD. WIND WILL GENERALLY
BE LESS THAN 10 KT.
BEYOND 12Z SUN...WIDESPREAD STEADY RAIN IS EXPECTED TO DEVELOP
DURING THE DAYTIME SUNDAY AND LAST INTO EARLY MONDAY...RESULTING IN
IFR OR PERHAPS LIFR CONDITIONS ACROSS MUCH OF CENTRAL NC DURING THIS
TIME. THEREAFTER...PRECIP AND REDUCED FLT CONDITIONS WILL DECREASE
IN COVERAGE DURING THE FIRST HALF OF NEXT WEEK...THEN CONDITIONS
EXPECTED TO FINALLY IMPROVE TO VFR DURING THE MIDDLE TO LATTER
PORTION OF NEXT WEEK AFTER A COLD FRONT MOVES ACROSS THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...MLM/NP
SHORT TERM...NP
LONG TERM...BLS
AVIATION...MLM/NP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
935 AM EDT SAT AUG 9 2014
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE SOUTHEAST INTO EARLY NEXT
WEEK. AREAS OF LOW PRESSURE WILL MOVE ALONG THE FRONT TODAY
THROUGH TUESDAY. THE FRONT WILL DISSIPATE BY MIDWEEK. THE NEXT
FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY AND PUSH THROUGH
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 915 AM SAT...BASED ON RADAR AND OBSERVATIONS INCREASED POPS
TO CATEGORICAL TO LIKELY ACROSS NORTHERN AREAS AS A BAND OF LIGHT
TO MODERATE SHOWERS MOVES SE ACROSS THAT AREA. RUC MODEL SEEMED TO
HANDLE PRECIP AREAS WELL IN THE NEAR TERM. AT THE SAME TIME
DECREASED POPS TO AROUND 50 PERCENT THROUGH NOON. MOST MODELS
CONTINUE TO INDICATE HIGHEST THREAT FOR THE AFTERNOON ACROSS
SOUTHERN AREAS...ALTHOUGH THERE ARE SOME OUTLIERS. HARD TO NAIL
DOWN EXACT AREAS FOR LATER THIS AFTERNOON SO MAINTAINED LIKELY
POPS EVERYWHERE. DID NOT TWEAK TEMPS MUCH. ALSO MADE MINOR
ADJUSTMENTS TO INCREASE WINDS JUST A BIT...ESPECIALLY ALONG
SOUTHERN COASTAL AREAS.
PREV DISC...USED A BLEND OF THE LATEST GFS/ECMWF FOR THE SHORT
TERM. THE STATIONARY FRONT WILL LINGER TO THE SOUTH WITH AN AREA
OF LOW PRESSURE MOVING EAST ALONG IT OVER SOUTH CAROLINA TODAY
WITH SEVERAL WEAK UPPER DISTURBANCES MOVING THROUGH THE WEST
NORTHWEST FLOW ALOFT. FORECAST SOUNDINGS SHOW BEST INSTABILITY
FOR THUNDER ONLY OVER THE SOUTHWEST COUNTIES THIS AFTERNOON WITH
THE REMAINDER OF THE AREA TOO STABLE. OVERCAST SKIES AND RAIN WILL
KEEP TEMPERATURES DOWN...WITH UPPER 70S TO LOWER 80S THROUGHOUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 3 AM SAT...SETUP TONIGHT IS SIMILAR. NEXT WAVE OF LOW
PRESSURE MOVING ALONG THE FRONT WILL PASS JUST TO THE SOUTH
TONIGHT WITH WEAK VORT CENTERS PASSING THROUGH ALOFT. SOUNDINGS
SHOW ATMOSPHERE CONTINUES TO MOISTEN UP SO HAVE LIKELY POPS
CONTINUING ALONG THE COASTAL PLAIN AND 50% OUTER BANKS. ENOUGH
INSTABILITY FOR THUNDER THROUGHOUT SO INCLUDED A MENTION ALL
ZONES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 320 AM SATURDAY...LOW PRESSURE WILL TRAVERSE A WEAK STALLED
FRONTAL BOUNDARY TO OUR SOUTH SUNDAY INTO MONDAY. WITH A DEEP FEED
OF MOISTURE WITH PRECIPITABLE WATER VALUES IN EXCESS OF 2
INCHES...EXPECT WIDESPREAD SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS. MODEL TRENDS HAVE BACKED OFF ON QPF OVER OUR CWA
WITH THE AXIS OF THE BEST MOISTURE FLUX OVER THE PIEDMONT.
CONSENSUS OF MODEL QPF HAS EASTERN NC IN AN AREA OF GENERALLY ONE
INCH OF RAINFALL OR LESS...AND IT APPEARS TO BE MAINLY STRATIFORM
WITH ONLY OCCASIONALLY EMBEDDED CONVECTION. AS A RESULT...DO NOT
THINK A FLOOD WATCH IS MERITED AT THIS TIME. WILL CONTINUE TO
MONITOR AS ANY SUSTAINED HEAVY RAINFALL...ON TOP OF THE ALREADY
SATURATED GROUND...COULD CAUSE FLOODING ISSUES. LIKELY TO
CATEGORICAL POPS FOR SUNDAY...WITH THE HIGHEST OVER THE
SOUTHWESTERN CWA. LIKELY POPS CONTINUE SUNDAY NIGHT AND MONDAY
BEFORE TAPERING TO HIGH CHANCE MONDAY NIGHT INTO TUESDAY. A COLD
FRONT WILL APPROACH THE REGION WEDNESDAY WITH SCATTERED
SHOWERS/TSTMS AHEAD OF THE FRONT. THURSDAY AND FRIDAY STILL APPEAR
TO BE FINALLY BE MUCH DRIER WITH HIGH PRESSURE BUILDING DOWN FROM
THE GREAT LAKES REGION. HAVE TRENDED MAX TEMPS BELOW GUIDANCE
SUNDAY INTO TUESDAY...BEFORE RETURNING TO NORMAL WITH LESS
PRECIPITATION FOR MID/LATE WEEK.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/
AS OF 3 AM SAT...SURFACE WINDS WILL REMAIN LIGHT EASTERLY THROUGH
TONIGHT. LIGHT RAIN WILL SLOWLY OVERSPREAD THE AREA FROM THE WEST
AND SOUTHWEST TODAY INTO TONIGHT. EXPECTING MVFR VISIBILITIES
TODAY AND MVFR CIGS/VSBYS TONIGHT. ANY THUNDER IS FORECAST TO BE
ISOLATED.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 325 AM SATURDAY...WET WEATHER WITH WIDESPREAD MOSTLY LIGHT
RAIN WILL KEEP TAFS IN MOSTLY THE MVFR RANGE SUNDAY AND MONDAY
WITH OCCASIONAL DROPS TO IFR IN ANY HEAVIER PRECIPITATION.
SHOWERS/TSTMS BECOME MORE SCATTERED TUESDAY/WEDNESDAY WITH ONLY
OCCASIONAL MVFR WITH PERHAPS LOWER VSBYS IN DENSE FOG LATE AT
NIGHT.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 915 AM SAT...MAD SOME ADJUSTMENTS TO INCREASE WINDS ACROSS
SOUTHERN WATERS BASED ON OBSERVATIONS AND LATEST RUC GUIDANCE.
SEEING WINDS SUSTAINED NEAR 15 KT WITH GUSTS TO 20 POSSIBLE FROM
AROUND CAPE LOOKOUT SOUTH. OTHERWISE NO SIGNIFICANT CHANGES TO
FORECAST.
PREVIOUS DISCUSSION...USED A MIX OF THE LATEST GFS/ECMWF FOR THE SHORT
TERM. THE STATIONARY FRONT WILL REMAIN TO THE SOUTH WITH TWO AREAS
OF LOW PRESSURE MOVING EAST ALONG IT...ONE TODAY AND THE OTHER
TONIGHT. WINDS WILL VEER SLOWLY TODAY INTO TONIGHT...FROM EAST
NORTHEAST THIS MORNING TO EAST SOUTHEAST TONIGHT. THE PRESSURE
GRADIENT WILL REMAIN VERY LOOSE AND AM FORECASTING WINDS NO HIGHER
THAN AROUND 10 KNOTS AND SEAS 2-4 FEET.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 325 AM SATURDAY...EXPECT GENERALLY EAST WINDS AT 15 KNOTS OR
LESS SUNDAY AND SUNDAY NIGHT WITH SEAS GENERALLY 2 TO 4 FEET
BUILDING TO 3 TO 5 FEET PER LOCAL SWAN/NWPS MODEL. GRADIENT WILL
TIGHTEN AS LOW PRESSURE MOVES ALONG THE STALLED COLD FRONT MONDAY
INTO MONDAY WITH WINDS INCREASING TO 15 TO 20 KNOTS AND SEAS 3 TO
5 FEET. SWAN AND WAVEWATCH SHOW SOME 6 FOOT SEAS OVER THE OUTER
PORTIONS OF THE CENTRAL AND NORTHERN WATERS...BUT WILL CAP AT 5
FEET AT THIS TIME. AS THE LOW PASSES NORTH OF THE REGION...WINDS
BACK TO W/SW BY TUESDAY INTO WEDNESDAY AND DROP BACK TO 15 KNOTS
OR LESS.
WILL HAVE MODERATE THREAT OF RIP CURRENTS ON ALL WATERS
TODAY...DUE MAINLY TO A HIGH ASTRONOMICAL TIDE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HSA
NEAR TERM...RSB/HSA
SHORT TERM...HSA
LONG TERM...CTC
AVIATION...CTC/HSA
MARINE...RSB/CTC/HSA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT SAT AUG 9 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING WET WEATHER TO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OF THIS MORNING/...
AS OF 650 AM SATURDAY...
TWO DISTINCT AREAS OF LIGHT RAIN ARE ONGOING ACROSS CENTRAL NC ATTM.
THE FIRST AREA ACROSS OUR NORTHERN AND FAR NORTHEAST ZONES...HAS
BEEN ONGOING MUCH OF THE OVERNIGHT AND EARLY MORNING HOURS AND
CONTINUES TO DRIFT FROM NW TO SE...DRIVEN IN PART BY A SHORT WAVE
TROUGH AND ASSOC SHEAR AXIS MOVING SE ACROSS VA. FARTHER SOUTH...
OVER THE PAST FEW HOURS ADDITIONAL RAIN HAS DEVELOPED FROM SW TOWARD
THE NE AS LOWER LEVEL ISENTROPIC UPGLIDE HAS HELPED LIFT...COOL...
AND SATURATE THE COLUMN WITH TIME. IN BOTH AREAS...RAINFALL AMOUNTS
ARE GENERALLY LIGHT. THE LATEST HRRR SHOWS THESE PROCESSES
CONTINUING THROUGH THE REST OF THE MORNING HOURS...WITH ADDITION
LIGHT RAIN CONTINUING OVER A GOOD PORTION OF CENTRAL NC. FOR THE
NEAR TERM UPDATE HAVE INCREASED POPS TO CATEGORICAL FOR THE MORNING
HOURS. TEMPS WILL BE SLOW TO RISE THIS MORNING WITH THE CLOUDS AND
RAIN...HOLDING IN THE LOWER 70S...PERHAPS GETTING INTO THE MID 70S
THIS AFTERNOON.
&&
.SHORT TERM /THIS AFTERNOON THROUGH SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...
NOT MUCH CHANGE IN THE FORECAST THINKING FROM PREV CYCLES...WITH
CLOUDY AND WET-AT-TIMES WEATHER FOR MUCH OF THIS WEEKEND...AS A
SERIES OF UPPER SHORT WAVES ARE PROGGED TO MOVE ACROSS OUR REGION
OVER TOP OF THE SFC BOUNDARY THAT IS PROGGED TO REMAIN SOMEWHERE
INVOF OF THE NC/SC BORDER. NORTH OF THIS BOUNDARY AND ACROSS THE
PIEDMONT...A HYBRID CAD PATTERN WILL PERSIST. THE MODELS RECENTLY
HAVE BEEN RATHER ROBUST WITH QPF VALUES...A CONSENSUS OF WHICH HAVE
GENERALLY BEEN PAINTING A PICTURE OF ANYWHERE BETWEEN 2 TO 4 (OR
MORE) INCHES OF RAIN ACROSS OUR CWA THIS WEEKEND...GENERALLY HIGHEST
WEST. WHILE ITS TOUGH TO PIN DOWN EXACTLY WHICH AREAS WILL RECEIVE
THE HEAVIEST RAIN AND WHAT THE FINAL TOTALS WILL BE...THE HEAVIEST
RAIN TODAY MAY END UP BEING CLOSER TO...AND JUST NORTH OF THE
BOUNDARY WHERE THE PRECIP WILL BE MORE CONVECTIVE IN NATURE...MUCH
LIKE THE CLUSTER OF RAIN SHOWERS THAT MOVED NORTH OUT OF NORTH-
CENTRAL SC A FEW HOURS AGO. WILL ALSO HAVE TO CLOSELY MONITOR THE
SHORT WAVE TROUGH NOW CROSSING THE CENTRAL PLAINS...AS MODELS SHOW
THIS WAVE MOVING SE AND INDUCING A WELL-DEFINED SFC LOW TO OUR SOUTH
ALONG THE AFOREMENTIONED BOUNDARY LATE SUNDAY AND SUNDAY NIGHT. THE
COMBINATION AND STRENGTHENING E/SE FLOW AHEAD OF THIS LOW...VIGOROUS
1000-850MB MOISTURE TRANSPORT ASSOC WITH THIS FLOW...AND ASCENT
OVERTOP THE WEDGE (ON THE N/NW SIDE OF THE SFC WAVE)...SHOULD RESULT
IN A PERIOD OF MODERATE TO HEAVY RAINFALL FROM LATE SUNDAY MORNING
LASTING THROUGH MUCH OF THE DAY SUNDAY AND PERHAPS INTO THE NIGHT-
TIME HOURS...WITH THE HEAVIEST RAIN ACROSS OUR PIEDMONT ZONES WHERE
CAD WILL BE DEEPER. THIS PERIOD OF TIME WILL LIKELY ACCOUNT FOR THE
BULK OF THE RAINFALL THAT WE GET WITH THIS SYSTEM.
IN TERMS OF IMPACTS...IF THE MODEL QPF IS CORRECT...THEN URBAN...
POOR DRAINAGE...AND SMALL CREEK FLOODING WOULD LIKELY BE A CONCERN
IN THE SHORTER TERM...THEN THE POTENTIAL FOR MINOR RIVER FLOODING IN
THE LONGER TERM. HOWEVER...THERE IS STILL A CONSIDERABLE AMOUNT OF
UNCERTAINLY AND LOWER-THAN-NORMAL CONFIDENCE IN THESE QPF VALUES...
ESP SINCE PRECIP HAS BEEN SOMEWHAT SLOWER TO DEVELOP SO FAR COMPARED
TO WHAT MODELS HAVE BEEN SUGGESTING. AS SUCH...WE PLAN TO HOLD OFF
ISSUING ANY FLOOD WATCHES ATTM...AND INSTEAD CONTINUE TO STRONGLY
WORD THE HWO. THEN IF THE PRECIP INDEED BEGINS TO DEVELOP AS MODELS
HAVE BEEN SUGGESTING...WE MAY NEED TO ISSUE A QUICK FLOOD WATCH FOR
THE AFOREMENTIONED CONCERNS.
OTHERWISE...GIVEN THE SFC BOUNDARY AND BEST INSTABILITY POSITIONED
TO OUR SOUTH...RIGHT NOW IT LOOKS LIKE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER OUR AREA WILL BE LOW DURING THIS WEEKEND.
TEMPS WILL BE A FUNCTION OF THE CLOUDS AND PRECIP...BUT OVERALL
EXPECTED TO RUN BELOW NORMAL FOR HIGHS (GENERALLY IN THE
70S...WARMEST SE) AND NEAR NORMAL FOR LOWS (MID-UPR 60S).
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
THE COLD AIR DAMMING AIRMASS WILL HOLD ON THROUGH
MONDAY...POTENTIALLY INTO TUESDAY...WHILE A MILLER TYPE-B LOW
PRESSURE MOVES SLOWLY ALONG THE STALLED FRONTAL ZONE OVER SC AND
EASTERN NC. THE UPPER LEVEL FLOW CONTINUES TO BE WEAK AND WEST-
NORTHWESTERLY WITH THE POTENTIAL FOR A FEW WEAK DISTURBANCES ALOFT.
AS THE SURFACE WAVE TRACKS NEAR FROM SC TOWARD THE NC COAST...THE
LOW-LEVEL FLOW OVER CENTRAL NC WEAKENS AND BACKS AROUND TO MORE EAST-
NORTH...REDUCING THE ISENTROPIC ACCENT OVER THE WEDGE AIRMASS.
THUS...THE PRIMARY FORCING SHOULD SHIFT TO THE ENHANCED LOW-LEVEL
CONVERGENCE OF NEAR THE SURFACE WAVE....AND PRECIP SHOULD BECOME
LESS WIDESPREAD/INTENSE. WILL MAINTAIN HIGHER POPS ACROSS THE
COASTAL PLAIN..BUT EXPECT PRECIP TO BECOME MORE DRIZZLY OVER THE
PIEDMONT. HIGHS WILL AGAIN BE WELL BELOW NORMAL AND NOT MUCH HIGHER
THAN SUNDAY...LOW/MID 70S NORTHWEST AND UPPER 70S SOUTHEAST. LOWS
MONDAY NIGHT IN THE UPPER 60S.
THE SURFACE WAVE WILL CONTINUE TO MOVE OFF TO THE NORTHEAST TUESDAY
WHILE THE PARENT LOW WEST OF THE MOUNTAINS LIFTS OFF TOWARD THE GREAT
LAKES. THE COLD FRONT ATTENDANT TO THE LOW SHOULD BE WHAT
ULTIMATELY CLEARS TO THE LINGERING WEDGE AIRMASS AND LOW CLOUDS
OUT...THOUGH SOME DRIER AIR ALOFT AHEAD OF THE FRONT MAY ALSO HELP.
IT IS POSSIBLE THAT THE LOW CLOUDS MAY THIN ON TUESDAY BUT NOT BE
COMPLETELY GONE UNTIL WEDNESDAY. WITHOUT BETTER DEEP FORCING
ACCOMPANYING THE FRONT OR A CHANCE FOR BETTER INSTABILITY...WILL
KEEP POPS IN THE CHANCE RANGE FOR TUESDAY INTO TUESDAY NIGHT. THE
COLD FRONT MAY BE VERY SLOW TO CLEAR THE AREA WEDNESDAY INTO
THURSDAY...AS DEPICTED BY THE GFS...BUT MUCH DRIER AIR THROUGH A
DEEP LAYER WILL BRING PRECIP CHANCES TO AN END BY WEEKS END...AS
ANOTHER UPPER TROUGH SETS UP OVER THE EASTERN US AND A DRY NORTHWEST
FLOW DOMINATES. THIS WILL ALSO LEAD TO TEMPS A CATEGORY OR SO BELOW
NORMAL...WITH HIGHS IN THE LOW/MID 80S AND LOWS IN THE LOW/MID 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
FOR THE 24 HOUR TAF PERIOD: OVER THE PAST FEW HOURS LIGHT RAIN HAS
STARTED TO FILL IN ACROSS CENTRAL NC...ESP EAST OF THE TRIAD REGION.
ASIDE FROM A FEW POCKETS OF HEAVIER RAIN...MOST OF THE RAIN IS
LIGHT. EVEN WITH THIS RAIN...FLT CONDITIONS REMAIN MOSTLY MVFR EAST
OF A LINE FROM KHNZ-KRDU-KRCZ. WEST OF THIS LINE WE`RE SEEING
NUMEROUS IFR CIGS AND VSBYS. REGIONAL RADAR TRENDS AND LATEST HRRR
SUGGEST THAT THE RAIN WILL CONTINUE TO EXPAND ACROSS MOST OF CENTRAL
NC THROUGH THE REST OF THE MORNING HOURS...WITH FLT CONDITIONS
FURTHER DETERIORATING EAST. THEREAFTER...EXPECT IFR TO LOW-MVFR
CONDITIONS THROUGH THE REST OF THE TAF PERIOD. WIND WILL GENERALLY
BE LESS THAN 10 KT.
BEYOND 12Z SUN...WIDESPREAD STEADY RAIN IS EXPECTED TO DEVELOP
DURING THE DAYTIME SUNDAY AND LAST INTO EARLY MONDAY...RESULTING IN
IFR OR PERHAPS LIFR CONDITIONS ACROSS MUCH OF CENTRAL NC DURING THIS
TIME. THEREAFTER...PRECIP AND REDUCED FLT CONDITIONS WILL DECREASE
IN COVERAGE DURING THE FIRST HALF OF NEXT WEEK...THEN CONDITIONS
EXPECTED TO FINALLY IMPROVE TO VFR DURING THE MIDDLE TO LATTER
PORTION OF NEXT WEEK AFTER A COLD FRONT MOVES ACROSS THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...BLS
AVIATION...NP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT SAT AUG 9 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING WET WEATHER TO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OVERNIGHT AND THIS MORNING/...
AS OF 315 AM SATURDAY...
WILL CONTINUE TO SEE LIGHT RAIN MOVE ACROSS OUR NORTHERN AND
NORTHEAST ZONES DRIVEN IN PART BY A SHORT WAVE TROUGH AND ASSOC
SHEAR AXIS MOVING SE ACROSS VA. FARTHER SOUTH ACROSS OUR SOUTHERN
COASTAL PLAIN ZONES...A CLUSTER OF SHALLOW CONVECTIVE CELLS THAT
MOVED OUT OF NORTH-CENTRAL SC AND INTO OUR SOUTHERN ZONES A FEW
HOURS AGO...HAVE SINCE DISSIPATED WHILE MOVING NORTHEAST AWAY FROM
THE STALLED SFC BOUNDARY AND TOWARD DRIER AIR. THE LATEST
HRRR...WHILE ADEQUATELY DEPICTING THE LIGHT RAIN ACROSS OUR NORTHERN
ZONES...SO FAR BASED ON CURRENT RADAR TRENDS...APPEARS TO BE TOO
AGGRESSIVE DEVELOPING ADDTIONAL RAIN OVER MUCH OF OUR CWA BETWEEN
NOW AND 12Z. EVEN STILL...AS LOWER LEVEL ISENTROPIC UPGLIDE
INCREASES ACROSS OUR CWA AND THE COLUMN CONTINUES TO BECOME MORE
SATURATED FROM WEST TO EAST WITH TIME...ADDITIONAL LIGHT RAIN OR
SCATTERED SHALLOW SHOWERS ARE EXPECTED TO DEVELOP...ALBETIT PROBABLY
LESS COVERAGE THAN THE CURRENT HRRR IS SUGGESTING. RAINFALL AMOUNTS
IN THE NORTHERN STRATIFORM PRECIP AREA WILL REMAIN LIGHT...WHILE
SOMEWHAT HEAVIER PRECIP WILL BE POSSIBLE WITH ANY SHALLOW CONVECTIVE
CELLS THAT DEVELOP FARTHER SOUTH CLOSER TO THE SFC BOUNDARY THAT IS
STALLED ACROSS CENTRAL SC.
&&
.SHORT TERM /THIS AFTERNOON THROUGH SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...
NOT MUCH CHANGE IN THE FORECAST THINKING FROM PREV CYCLES...WITH
CLOUDY AND WET-AT-TIMES WEATHER FOR MUCH OF THIS WEEKEND...AS A
SERIES OF UPPER SHORT WAVES ARE PROGGED TO MOVE ACROSS OUR REGION
OVER TOP OF THE SFC BOUNDARY THAT IS PROGGED TO REMAIN SOMEWHERE
INVOF OF THE NC/SC BORDER. NORTH OF THIS BOUNDARY AND ACROSS THE
PIEDMONT...A HYBRID CAD PATTERN WILL PERSIST. THE MODELS RECENTLY
HAVE BEEN RATHER ROBUST WITH QPF VALUES...A CONSENSUS OF WHICH HAVE
GENERALLY BEEN PAINTING A PICTURE OF ANYWHERE BETWEEN 2 TO 4 (OR
MORE) INCHES OF RAIN ACROSS OUR CWA THIS WEEKEND...GENERALLY HIGHEST
WEST. WHILE ITS TOUGH TO PIN DOWN EXACTLY WHICH AREAS WILL RECEIVE
THE HEAVIEST RAIN AND WHAT THE FINAL TOTALS WILL BE...THE HEAVIEST
RAIN TODAY MAY END UP BEING CLOSER TO...AND JUST NORTH OF THE
BOUNDARY WHERE THE PRECIP WILL BE MORE CONVECTIVE IN NATURE...MUCH
LIKE THE CLUSTER OF RAIN SHOWERS THAT MOVED NORTH OUT OF NORTH-
CENTRAL SC A FEW HOURS AGO. WILL ALSO HAVE TO CLOSELY MONITOR THE
SHORT WAVE TROUGH NOW CROSSING THE CENTRAL PLAINS...AS MODELS SHOW
THIS WAVE MOVING SE AND INDUCING A WELL-DEFINED SFC LOW TO OUR SOUTH
ALONG THE AFOREMENTIONED BOUNDARY LATE SUNDAY AND SUNDAY NIGHT. THE
COMBINATION AND STRENGTHENING E/SE FLOW AHEAD OF THIS LOW...VIGOROUS
1000-850MB MOISTURE TRANSPORT ASSOC WITH THIS FLOW...AND ASCENT
OVERTOP THE WEDGE (ON THE N/NW SIDE OF THE SFC WAVE)...SHOULD RESULT
IN A PERIOD OF MODERATE TO HEAVY RAINFALL FROM LATE SUNDAY MORNING
LASTING THROUGH MUCH OF THE DAY SUNDAY AND PERHAPS INTO THE NIGHT-
TIME HOURS...WITH THE HEAVIEST RAIN ACROSS OUR PIEDMONT ZONES WHERE
CAD WILL BE DEEPER. THIS PERIOD OF TIME WILL LIKELY ACCOUNT FOR THE
BULK OF THE RAINFALL THAT WE GET WITH THIS SYSTEM.
IN TERMS OF IMPACTS...IF THE MODEL QPF IS CORRECT...THEN URBAN...
POOR DRAINAGE...AND SMALL CREEK FLOODING WOULD LIKELY BE A CONCERN
IN THE SHORTER TERM...THEN THE POTENTIAL FOR MINOR RIVER FLOODING IN
THE LONGER TERM. HOWEVER...THERE IS STILL A CONSIDERABLE AMOUNT OF
UNCERTAINLY AND LOWER-THAN-NORMAL CONFIDENCE IN THESE QPF VALUES...
ESP SINCE PRECIP HAS BEEN SOMEWHAT SLOWER TO DEVELOP SO FAR COMPARED
TO WHAT MODELS HAVE BEEN SUGGESTING. AS SUCH...WE PLAN TO HOLD OFF
ISSUING ANY FLOOD WATCHES ATTM...AND INSTEAD CONTINUE TO STRONGLY
WORD THE HWO. THEN IF THE PRECIP INDEED BEGINS TO DEVELOP AS MODELS
HAVE BEEN SUGGESTING...WE MAY NEED TO ISSUE A QUICK FLOOD WATCH FOR
THE AFOREMENTIONED CONCERNS.
OTHERWISE...GIVEN THE SFC BOUNDARY AND BEST INSTABILITY POSITIONED
TO OUR SOUTH...RIGHT NOW IT LOOKS LIKE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER OUR AREA WILL BE LOW DURING THIS WEEKEND.
TEMPS WILL BE A FUNCTION OF THE CLOUDS AND PRECIP...BUT OVERALL
EXPECTED TO RUN BELOW NORMAL FOR HIGHS (GENERALLY IN THE
70S...WARMEST SE) AND NEAR NORMAL FOR LOWS (MID-UPR 60S).
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
THE COLD AIR DAMMING AIRMASS WILL HOLD ON THROUGH
MONDAY...POTENTIALLY INTO TUESDAY...WHILE A MILLER TYPE-B LOW
PRESSURE MOVES SLOWLY ALONG THE STALLED FRONTAL ZONE OVER SC AND
EASTERN NC. THE UPPER LEVEL FLOW CONTINUES TO BE WEAK AND WEST-
NORTHWESTERLY WITH THE POTENTIAL FOR A FEW WEAK DISTURBANCES ALOFT.
AS THE SURFACE WAVE TRACKS NEAR FROM SC TOWARD THE NC COAST...THE
LOW-LEVEL FLOW OVER CENTRAL NC WEAKENS AND BACKS AROUND TO MORE EAST-
NORTH...REDUCING THE ISENTROPIC ACCENT OVER THE WEDGE AIRMASS.
THUS...THE PRIMARY FORCING SHOULD SHIFT TO THE ENHANCED LOW-LEVEL
CONVERGENCE OF NEAR THE SURFACE WAVE....AND PRECIP SHOULD BECOME
LESS WIDESPREAD/INTENSE. WILL MAINTAIN HIGHER POPS ACROSS THE
COASTAL PLAIN..BUT EXPECT PRECIP TO BECOME MORE DRIZZLY OVER THE
PIEDMONT. HIGHS WILL AGAIN BE WELL BELOW NORMAL AND NOT MUCH HIGHER
THAN SUNDAY...LOW/MID 70S NORTHWEST AND UPPER 70S SOUTHEAST. LOWS
MONDAY NIGHT IN THE UPPER 60S.
THE SURFACE WAVE WILL CONTINUE TO MOVE OFF TO THE NORTHEAST TUESDAY
WHILE THE PARENT LOW WEST OF THE MOUNTAINS LIFTS OFF TOWARD THE GREAT
LAKES. THE COLD FRONT ATTENDANT TO THE LOW SHOULD BE WHAT
ULTIMATELY CLEARS TO THE LINGERING WEDGE AIRMASS AND LOW CLOUDS
OUT...THOUGH SOME DRIER AIR ALOFT AHEAD OF THE FRONT MAY ALSO HELP.
IT IS POSSIBLE THAT THE LOW CLOUDS MAY THIN ON TUESDAY BUT NOT BE
COMPLETELY GONE UNTIL WEDNESDAY. WITHOUT BETTER DEEP FORCING
ACCOMPANYING THE FRONT OR A CHANCE FOR BETTER INSTABILITY...WILL
KEEP POPS IN THE CHANCE RANGE FOR TUESDAY INTO TUESDAY NIGHT. THE
COLD FRONT MAY BE VERY SLOW TO CLEAR THE AREA WEDNESDAY INTO
THURSDAY...AS DEPICTED BY THE GFS...BUT MUCH DRIER AIR THROUGH A
DEEP LAYER WILL BRING PRECIP CHANCES TO AN END BY WEEKS END...AS
ANOTHER UPPER TROUGH SETS UP OVER THE EASTERN US AND A DRY NORTHWEST
FLOW DOMINATES. THIS WILL ALSO LEAD TO TEMPS A CATEGORY OR SO BELOW
NORMAL...WITH HIGHS IN THE LOW/MID 80S AND LOWS IN THE LOW/MID 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM SATURDAY...
THROUGH THE 24 HOUR TAF PERIOD...SUB-VFR CONDITIONS CAN BE EXPECTED
FOR MUCH OF THE PERIOD WITH REDUCED VSBY AND CIGS IN LIGHT RAIN.
THROUGH 14Z THIS MORNING...LOCATIONS WEST OF A KRWI-KFAY LINE WILL
HAVE THE BEST CHANCE TO SEE LOW-MVFR OR IFR CONDITIONS...WHILE
LINGERING DRY MID LEVEL AIR EAST OF THIS LINE MAY DELAY THE ONSET OF
SUB-VFR CONDITIONS. HOWEVER AS THE DAY PROGRESSES EXPECT SUB-VFR
CONDITIONS TO OVERSPREAD ALL OF CENTRAL NC...WITH THE LOWEST CIGS
EXPECTED ACROSS THE TRIAD.
BEYOND 06Z SUN...WIDESPREAD STEADY RAIN IS EXPECTED TO DEVELOP
DURING THE DAYTIME SUNDAY AND LAST INTO EARLY MONDAY...RESULTING IN
IFR OR PERHAPS LIFR CONDITIONS ACROSS MUCH OF CENTRAL NC DURING THIS
TIME. THEREAFTER...PRECIP AND REDUCED FLT CONDITIONS WILL DECREASE
IN COVERGE DURING THE FIRST HALF OF NEXT WEEK...THEN CONDITIONS
EXPECTED TO FINALLY IMPROVE TO VFR DURING THE MIDDLE TO LATTER
PORTION OF NEXT WEEK AFTER A COLD FRONT MOVES ACROSS THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...BLS
AVIATION...NP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT SAT AUG 9 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING WET WEATHER TO THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OVERNIGHT AND THIS MORNING/...
AS OF 315 AM SATURDAY...
WILL CONTINUE TO SEE LIGHT RAIN MOVE ACROSS OUR NORTHERN AND
NORTHEAST ZONES DRIVEN IN PART BY A SHORT WAVE TROUGH AND ASSOC
SHEAR AXIS MOVING SE ACROSS VA. FARTHER SOUTH ACROSS OUR SOUTHERN
COASTAL PLAIN ZONES...A CLUSTER OF SHALLOW CONVECTIVE CELLS THAT
MOVED OUT OF NORTH-CENTRAL SC AND INTO OUR SOUTHERN ZONES A FEW
HOURS AGO...HAVE SINCE DISSIPATED WHILE MOVING NORTHEAST AWAY FROM
THE STALLED SFC BOUNDARY AND TOWARD DRIER AIR. THE LATEST
HRRR...WHILE ADEQUATELY DEPICTING THE LIGHT RAIN ACROSS OUR NORTHERN
ZONES...SO FAR BASED ON CURRENT RADAR TRENDS...APPEARS TO BE TOO
AGGRESSIVE DEVELOPING ADDTIONAL RAIN OVER MUCH OF OUR CWA BETWEEN
NOW AND 12Z. EVEN STILL...AS LOWER LEVEL ISENTROPIC UPGLIDE
INCREASES ACROSS OUR CWA AND THE COLUMN CONTINUES TO BECOME MORE
SATURATED FROM WEST TO EAST WITH TIME...ADDITIONAL LIGHT RAIN OR
SCATTERED SHALLOW SHOWERS ARE EXPECTED TO DEVELOP...ALBETIT PROBABLY
LESS COVERAGE THAN THE CURRENT HRRR IS SUGGESTING. RAINFALL AMOUNTS
IN THE NORTHERN STRATIFORM PRECIP AREA WILL REMAIN LIGHT...WHILE
SOMEWHAT HEAVIER PRECIP WILL BE POSSIBLE WITH ANY SHALLOW CONVECTIVE
CELLS THAT DEVELOP FARTHER SOUTH CLOSER TO THE SFC BOUNDARY THAT IS
STALLED ACROSS CENTRAL SC.
&&
.SHORT TERM /THIS AFTERNOON THROUGH SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...
NOT MUCH CHANGE IN THE FORECAST THINKING FROM PREV CYCLES...WITH
CLOUDY AND WET-AT-TIMES WEATHER FOR MUCH OF THIS WEEKEND...AS A
SERIES OF UPPER SHORT WAVES ARE PROGGED TO MOVE ACROSS OUR REGION
OVER TOP OF THE SFC BOUNDARY THAT IS PROGGED TO REMAIN SOMEWHERE
INVOF OF THE NC/SC BORDER. NORTH OF THIS BOUNDARY AND ACROSS THE
PIEDMONT...A HYBRID CAD PATTERN WILL PERSIST. THE MODELS RECENTLY
HAVE BEEN RATHER ROBUST WITH QPF VALUES...A CONSENSUS OF WHICH HAVE
GENERALLY BEEN PAINTING A PICTURE OF ANYWHERE BETWEEN 2 TO 4 (OR
MORE) INCHES OF RAIN ACROSS OUR CWA THIS WEEKEND...GENERALLY HIGHEST
WEST. WHILE ITS TOUGH TO PIN DOWN EXACTLY WHICH AREAS WILL RECEIVE
THE HEAVIEST RAIN AND WHAT THE FINAL TOTALS WILL BE...THE HEAVIEST
RAIN TODAY MAY END UP BEING CLOSER TO...AND JUST NORTH OF THE
BOUNDARY WHERE THE PRECIP WILL BE MORE CONVECTIVE IN NATURE...MUCH
LIKE THE CLUSTER OF RAIN SHOWERS THAT MOVED NORTH OUT OF NORTH-
CENTRAL SC A FEW HOURS AGO. WILL ALSO HAVE TO CLOSELY MONITOR THE
SHORT WAVE TROUGH NOW CROSSING THE CENTRAL PLAINS...AS MODELS SHOW
THIS WAVE MOVING SE AND INDUCING A WELL-DEFINED SFC LOW TO OUR SOUTH
ALONG THE AFOREMENTIONED BOUNDARY LATE SUNDAY AND SUNDAY NIGHT. THE
COMBINATION AND STRENGTHENING E/SE FLOW AHEAD OF THIS LOW...VIGOROUS
1000-850MB MOISTURE TRANSPORT ASSOC WITH THIS FLOW...AND ASCENT
OVERTOP THE WEDGE (ON THE N/NW SIDE OF THE SFC WAVE)...SHOULD RESULT
IN A PERIOD OF MODERATE TO HEAVY RAINFALL FROM LATE SUNDAY MORNING
LASTING THROUGH MUCH OF THE DAY SUNDAY AND PERHAPS INTO THE NIGHT-
TIME HOURS...WITH THE HEAVIEST RAIN ACROSS OUR PIEDMONT ZONES WHERE
CAD WILL BE DEEPER. THIS PERIOD OF TIME WILL LIKELY ACCOUNT FOR THE
BULK OF THE RAINFALL THAT WE GET WITH THIS SYSTEM.
IN TERMS OF IMPACTS...IF THE MODEL QPF IS CORRECT...THEN URBAN...
POOR DRAINAGE...AND SMALL CREEK FLOODING WOULD LIKELY BE A CONCERN
IN THE SHORTER TERM...THEN THE POTENTIAL FOR MINOR RIVER FLOODING IN
THE LONGER TERM. HOWEVER...THERE IS STILL A CONSIDERABLE AMOUNT OF
UNCERTAINLY AND LOWER-THAN-NORMAL CONFIDENCE IN THESE QPF VALUES...
ESP SINCE PRECIP HAS BEEN SOMEWHAT SLOWER TO DEVELOP SO FAR COMPARED
TO WHAT MODELS HAVE BEEN SUGGESTING. AS SUCH...WE PLAN TO HOLD OFF
ISSUING ANY FLOOD WATCHES ATTM...AND INSTEAD CONTINUE TO STRONGLY
WORD THE HWO. THEN IF THE PRECIP INDEED BEGINS TO DEVELOP AS MODELS
HAVE BEEN SUGGESTING...WE MAY NEED TO ISSUE A QUICK FLOOD WATCH FOR
THE AFOREMENTIONED CONCERNS.
OTHERWISE...GIVEN THE SFC BOUNDARY AND BEST INSTABILITY POSITIONED
TO OUR SOUTH...RIGHT NOW IT LOOKS LIKE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER OUR AREA WILL BE LOW DURING THIS WEEKEND.
TEMPS WILL BE A FUNCTION OF THE CLOUDS AND PRECIP...BUT OVERALL
EXPECTED TO RUN BELOW NORMAL FOR HIGHS (GENERALLY IN THE
70S...WARMEST SE) AND NEAR NORMAL FOR LOWS (MID-UPR 60S).
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...
LATEST GFS AND ECMWF EXHIBIT STRONG CONSENSUS WITH THE PERSISTENT
DAMMING REGIME MAINTAINING A FAMILIAR BUT ANOMALOUSLY UNSEASONABLE
WINTRY LOOK AS IT EVOLVES EARLY IN THE WORK WEEK. WHILE THE PARENT
HIGH EDGES OFF THE MID ATLANTIC COAST...ISENTROPIC LIFT IS
MAINTAINED...ALBEIT MORE EASTERLY AND WEAKER...ON MONDAY BY
DEVELOPMENT OF A COASTAL LOW IN RESPONSE TO A SHORT WAVE APPROACHING
IN THE NORTHWEST MID LEVEL FLOW. THIS MILLER-B LOOKING PATTERN
EFFECTIVELY LOCKS COOL AIR IN PLACE...AND ONGOING FORECAST HIGHS
MONDAY OF 75-80 DEGREES ARE ON TRACK...BUT COULD BE A COUPLE OF
DEGREES ON THE HIGH SIDE IF RAIN IS MORE WIDESPREAD. WILL BE RAISING
POPS ACROSS THE BOARD...BUT MORE SO IN THE EAST WHERE THE EFFECTS OF
EASTERLY ISENTROPIC LIFT AND LOW LEVEL CONVERGENCE IN THE VICINITY
OF THE SURFACE LOW WILL BE CONCENTRATED.
THE SURFACE LOW OVER THE NORTHWEST LIFTS INTO THE GREAT LAKES AND
COASTAL SYSTEM WEAKENS...BUT SITU DAMMING WILL CONTINUE THROUGH
TUESDAY AS SCOURING WILL BE SLOW...BASICALLY FROM THE TOP DOWN FROM
HEATING. THE PATTERN FINALLY BREAKS DURING THE MID WEEK AS DEEPER
MOISTURE WILL GET A PUSH EAST AND OFFSHORE LATER WEDNESDAY AS THE
UPPER TROF AXIS OVER THE MID WEST ROTATES ACROSS THE GREAT LAKES AND
PUSHES A FRONT AND DRIER AIR INTO THE AREA FROM THE NORTHWEST.
CHANCES OF RAIN WILL TAIL OFF FROM LIKELY ON MONDAY TO CHANCES ON
TUESDAY INTO WEDNESDAY...WITH DRY WEATHER FINALLY SETTLING IN FOR
THURSDAY AND FRIDAY. MEANWHILE...UNSEASONABLY COOL TEMPS WILL PERSIST
THROUGH THE END OF THE WEEK...WITH HIGHS FROM 80 TO 85 TUESDAY
THROUGH FRIDAY. MORNING LOWS WILL BE IN THE 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 315 AM SATURDAY...
THROUGH THE 24 HOUR TAF PERIOD...SUB-VFR CONDITIONS CAN BE EXPECTED
FOR MUCH OF THE PERIOD WITH REDUCED VSBY AND CIGS IN LIGHT RAIN.
THROUGH 14Z THIS MORNING...LOCATIONS WEST OF A KRWI-KFAY LINE WILL
HAVE THE BEST CHANCE TO SEE LOW-MVFR OR IFR CONDITIONS...WHILE
LINGERING DRY MID LEVEL AIR EAST OF THIS LINE MAY DELAY THE ONSET OF
SUB-VFR CONDITIONS. HOWEVER AS THE DAY PROGRESSES EXPECT SUB-VFR
CONDITIONS TO OVERSPREAD ALL OF CENTRAL NC...WITH THE LOWEST CIGS
EXPECTED ACROSS THE TRIAD.
BEYOND 06Z SUN...WIDESPREAD STEADY RAIN IS EXPECTED TO DEVELOP
DURING THE DAYTIME SUNDAY AND LAST INTO EARLY MONDAY...RESULTING IN
IFR OR PERHAPS LIFR CONDITIONS ACROSS MUCH OF CENTRAL NC DURING THIS
TIME. THEREAFTER...PRECIP AND REDUCED FLT CONDITIONS WILL DECREASE
IN COVERGE DURING THE FIRST HALF OF NEXT WEEK...THEN CONDITIONS
EXPECTED TO FINALLY IMPROVE TO VFR DURING THE MIDDLE TO LATTER
PORTION OF NEXT WEEK AFTER A COLD FRONT MOVES ACROSS THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...MLM
AVIATION...NP
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1043 PM EDT SUN AUG 10 2014
.SYNOPSIS...
STRENGTHENING LOW PRESSURE IN OHIO VALLEY LIFTS NORTHEAST INTO
NORTHERN OHIO BY MONDAY EVENING. DEEPER MOISTURE LIFTS NORTHEAST AS
STEERING FLOW INCREASES. COLD FRONT LATE TUESDAY. DRIER WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
1030 PM UPDATE...
FCST ON TRACK.
830 PM UPDATE...
NAM12 AND NEAR TERM MODELS SHOW A LULL IN ACTIVITY AFTER SUNSET
BEFORE AN UPTICK LATER IN THE OVERNIGHT WITH WEAK S/W TROUGH AND
WARM ADVECTION. TRIMMED BACK LIKELY POPS 03-06Z...FCST OTHERWISE ON
TRACK.
PREV DISCN...
DESPITE THE STEERING FLOW INCREASING ON MONDAY...STILL CONCERNED
ABOUT DOWNPOURS THROUGH THIS NEAR TERM...WITH THIS HAZARD ALSO
SPILLING OVER INTO MONDAY NIGHT.
WITH THE SOUTHEAST LOW LEVEL FLOW REMAINING INTO MONDAY...THE MOST
UNSTABLE AIR EXPECTED TO REMAIN IN THE TRI STATE OF SOUTHERN OHIO
AND EASTERN KENTUCKY OVERNIGHT...BEFORE INCREASING FURTHER EAST LATE
MONDAY AFTERNOON. AS OF MID AFTERNOON ON SUNDAY...WE ARE STILL
TAKING THE ATTITUDE OF MONITORING THE RADAR AND NEAR TERM MODELS...
BEFORE POSTING ANY FLASH FLOOD WATCH HEADLINE. OF COURSE...OUR
SOUTHERN WV COAL FIELD COUNTIES ARE MOST VULNERABLE...WITH CONCERNS
ABOVE 1.5 INCHES. BUT EVEN IN OUR DRIER COUNTIES...THE FLASH FLOOD
THREAT REMAINS. WILL CONTINUE THE HAZARDS IN THE HAZARDOUS WEATHER
POTENTIAL.
WILL LEAVE HEAVY RAIN MENTIONED WITH HIGHER POPS THROUGH MONDAY.
THE SOUTHEAST LOW LEVEL FLOW INCREASES OVERNIGHT...AS THE MID LEVELS
STARTS TURNING OUT OF THE SOUTH AND SOUTHWEST. 12Z MODELS AGREEING
MORE WITH THE RAP PULLING THE INITIAL DEEPER MOISTURE NORTH
OVERNIGHT INTO EASTERN OHIO AND NORTHERN WEST VIRGINIA BY MONDAY
MORNING. WILL HAVE A BAND OF HIGHER POPS WITH THAT...COVERAGE STILL
DEBATABLE WITH THE SE LOW LEVEL FLOW ALONG THE WESTERN SLOPES.
THE NAM STILL TRIES TO ANOTHER PCPN MAX ALONG THE EASTERN SLOPES IN
POCAHONTAS COUNTY...BUT NOT SOLD ON THAT SOLUTION.
AFTER THE MORNING SHOWERS LIFT NORTH...HAVE HIGHER POPS DEVELOPING
IN THE AFTERNOON OVER OHIO AND KENTUCKY MOVING INTO WV LATE IN THE
DAY.
STILL WORKING ON FINE TUNING TEMPERATURES FOR TONIGHT AND MONDAY BUT
DO NOT FORESEE ANY MAJOR CHANGES.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SURFACE LOW WILL BE MOVING THROUGH THE GREAT LAKES TUESDAY INTO
WEDNESDAY...WITH UPPER LEVEL TROUGH APPROACHING FROM THE WEST. HAVE
COLD FRONT CROSSING TUESDAY...WITH A SECONDARY SURFACE TROUGH/COLD
FRONT TUESDAY EVENING INTO TUESDAY NIGHT. CAPE TOPS 1000J/KG
TUESDAY...AND WITH CONVERGENCE ALONG THE FRONT HELPING...CANNOT
RULE OUT A STRONGER CELL OR TWO TUESDAY. WITH UPPER TROUGH LAGGING
BEHIND HAVE SOME CHANCE POPS...MAINLY IN THE MOUNTAINS...LINGERING
INTO WEDNESDAY MORNING WITH CLOUDS BREAKING UP FROM WEST TO EAST
THROUGH THE DAY.
BLENDED IN BIAS-CORRECTED CONSENSUS GUIDANCE FOR HIGHS AND
LOWS...RESULTING IN MINIMAL CHANGES TO PREVIOUS FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PRECIP SHOULD BE GONE BY THE START OF THE LONG TERM...WITH A FAIRLY
DRY FORECAST INTO THE WEEKEND WITH SURFACE HIGH PRESSURE. DO HAVE
WEAK NW FLOW ALOFT...SO COULD HAVE A VORT MAX SLIDE THROUGH AT SOME
POINT...BUT CONFIDENCE TOO LOW TO PLUG ANYTHING SPECIFIC IN. STAYED
FAIRLY CLOSE TO WPC GUIDANCE THROUGH THE PERIOD.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
FRONT STALLED SW OF THE AREA FINALLY MAKES A MOVE NEWD...APPROACHING
THE AREA OVERNIGHT...AND THEN PUSHING ON THROUGH THE AREA ON
MON...IN RESPONSE TO INCREASING STEERING FLOW ALOFT. THE SHOWERS
OVER THE MIDDLE OHIO VALLEY...TUG FORK...AS WELL AS THE BATCH OVER
CENTRAL WV...WILL WEAKEN OR DISSIPATE 01-02Z. BUT...AS THE WARM
FRONT APPROACHES OVERNIGHT...SHOWERS WILL INCREASE IN COVERAGE OVER
THE MIDDLE OHIO VALLEY AND SOUTHERN WV...AND THEN MOVE NEWD ACROSS
WV ON MON. THESE SHOWERS WILL THEN CLEAR OUT MON AFTERNOON...IN
TIME FOR SHOWERS AND THUNDERSTORMS TO BEGIN POPPING OVER THE MIDDLE
OHIO VALLEY IN THE AFTERNOON HEAT...AND OUT AHEAD OF A COLD FRONT
APPROACHING FROM THE W.
THE SHOWERS WILL CREATE MVFR CONDITIONS AT TIMES. IFR IS MOST
LIKELY IN ANY HEAVIER SHOWER OR THUNDERSTORM...AND IN THE WAKE OF
SHOWERS EARLY MON MORNING.
BKW WILL HAVE MVFR STRATUS IN GUSTY SE FLOW THROUGH THE PD...PERHAPS
HIGH IFR EARLY MON MORNING. OTHERWISE S TO SE SFC FLOW OVERNIGHT
WILL BECOME GUSTY ON MON. LIGHT S FLOW ALOFT WILL BECOME MODERATE S
TO SW OVERNIGHT...AND THEN LIGHT TO MODERATE S TO SW ON MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: AVIATION CONDITIONS ARE LIKELY TO VARY
OVERNIGHT INTO MON MORNING WITH THE APPROACH OF A WARM FRONT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/11/14
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H M M M H H H H H H H
BKW CONSISTENCY M M L L M H H H M M H M
EKN CONSISTENCY M M M H H H M M M M M H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z TUESDAY...
IFR CONDITIONS IN ROUNDS OF SHOWERS AND THUNDERSTORMS MON NT...POST
RAIN STRATUS TUE MORNING...AND ONE LAST ROUND OF THUNDERSTORMS LATER
TUE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM/MZ
NEAR TERM...KTB/TRM
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
815 PM EDT SUN AUG 10 2014
.SYNOPSIS...
STRENGTHENING LOW PRESSURE IN OHIO VALLEY LIFTS NORTHEAST INTO
NORTHERN OHIO BY MONDAY EVENING. DEEPER MOISTURE LIFTS NORTHEAST AS
STEERING FLOW INCREASES. COLD FRONT LATE TUESDAY. DRIER WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
NAM12 AND NEAR TERM MODELS SHOW A LULL IN ACTIVITY AFTER SUNSET
BEFORE AN UPTICK LATER IN THE OVERNIGHT WITH WEAK S/W TROUGH AND
WARM ADVECTION. TRIMMED BACK LIKELY POPS 03-06Z...FCST OTHERWISE ON
TRACK.
PREV DISCN...
DESPITE THE STEERING FLOW INCREASING ON MONDAY...STILL CONCERNED
ABOUT DOWNPOURS THROUGH THIS NEAR TERM...WITH THIS HAZARD ALSO
SPILLING OVER INTO MONDAY NIGHT.
WITH THE SOUTHEAST LOW LEVEL FLOW REMAINING INTO MONDAY...THE MOST
UNSTABLE AIR EXPECTED TO REMAIN IN THE TRI STATE OF SOUTHERN OHIO
AND EASTERN KENTUCKY OVERNIGHT...BEFORE INCREASING FURTHER EAST LATE
MONDAY AFTERNOON. AS OF MID AFTERNOON ON SUNDAY...WE ARE STILL
TAKING THE ATTITUDE OF MONITORING THE RADAR AND NEAR TERM MODELS...
BEFORE POSTING ANY FLASH FLOOD WATCH HEADLINE. OF COURSE...OUR
SOUTHERN WV COAL FIELD COUNTIES ARE MOST VULNERABLE...WITH CONCERNS
ABOVE 1.5 INCHES. BUT EVEN IN OUR DRIER COUNTIES...THE FLASH FLOOD
THREAT REMAINS. WILL CONTINUE THE HAZARDS IN THE HAZARDOUS WEATHER
POTENTIAL.
WILL LEAVE HEAVY RAIN MENTIONED WITH HIGHER POPS THROUGH MONDAY.
THE SOUTHEAST LOW LEVEL FLOW INCREASES OVERNIGHT...AS THE MID LEVELS
STARTS TURNING OUT OF THE SOUTH AND SOUTHWEST. 12Z MODELS AGREEING
MORE WITH THE RAP PULLING THE INITIAL DEEPER MOISTURE NORTH
OVERNIGHT INTO EASTERN OHIO AND NORTHERN WEST VIRGINIA BY MONDAY
MORNING. WILL HAVE A BAND OF HIGHER POPS WITH THAT...COVERAGE STILL
DEBATABLE WITH THE SE LOW LEVEL FLOW ALONG THE WESTERN SLOPES.
THE NAM STILL TRIES TO ANOTHER PCPN MAX ALONG THE EASTERN SLOPES IN
POCAHONTAS COUNTY...BUT NOT SOLD ON THAT SOLUTION.
AFTER THE MORNING SHOWERS LIFT NORTH...HAVE HIGHER POPS DEVELOPING
IN THE AFTERNOON OVER OHIO AND KENTUCKY MOVING INTO WV LATE IN THE
DAY.
STILL WORKING ON FINE TUNING TEMPERATURES FOR TONIGHT AND MONDAY BUT
DO NOT FORESEE ANY MAJOR CHANGES.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SURFACE LOW WILL BE MOVING THROUGH THE GREAT LAKES TUESDAY INTO
WEDNESDAY...WITH UPPER LEVEL TROUGH APPROACHING FROM THE WEST. HAVE
COLD FRONT CROSSING TUESDAY...WITH A SECONDARY SURFACE TROUGH/COLD
FRONT TUESDAY EVENING INTO TUESDAY NIGHT. CAPE TOPS 1000J/KG
TUESDAY...AND WITH CONVERGENCE ALONG THE FRONT HELPING...CANNOT
RULE OUT A STRONGER CELL OR TWO TUESDAY. WITH UPPER TROUGH LAGGING
BEHIND HAVE SOME CHANCE POPS...MAINLY IN THE MOUNTAINS...LINGERING
INTO WEDNESDAY MORNING WITH CLOUDS BREAKING UP FROM WEST TO EAST
THROUGH THE DAY.
BLENDED IN BIAS-CORRECTED CONSENSUS GUIDANCE FOR HIGHS AND
LOWS...RESULTING IN MINIMAL CHANGES TO PREVIOUS FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PRECIP SHOULD BE GONE BY THE START OF THE LONG TERM...WITH A FAIRLY
DRY FORECAST INTO THE WEEKEND WITH SURFACE HIGH PRESSURE. DO HAVE
WEAK NW FLOW ALOFT...SO COULD HAVE A VORT MAX SLIDE THROUGH AT SOME
POINT...BUT CONFIDENCE TOO LOW TO PLUG ANYTHING SPECIFIC IN. STAYED
FAIRLY CLOSE TO WPC GUIDANCE THROUGH THE PERIOD.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FRONT STALLED SW OF THE AREA FINALLY MAKES A MOVE NEWD...APPROACHING
THE AREA OVERNIGHT...AND THEN PUSHING ON THROUGH THE AREA ON
MON...IN RESPONSE TO INCREASING STEERING FLOW ALOFT. THE SHOWERS
OVER THE MIDDLE OHIO VALLEY...TUG FORK...AS WELL AS THE BATCH OVER
CENTRAL WV...WILL WEAKEN OR DISSIPATE 01-02Z. BUT...AS THE WARM
FRONT APPROACHES OVERNIGHT...SHOWERS WILL INCREASE IN COVERAGE OVER
THE MIDDLE OHIO VALLEY AND SOUTHERN WV...AND THEN MOVE NEWD ACROSS
WV ON MON. THESE SHOWERS WILL THEN CLEAR OUT MON AFTERNOON...IN
TIME FOR SHOWERS AND THUNDERSTORMS TO BEGIN POPPING OVER THE MIDDLE
OHIO VALLEY IN THE AFTERNOON HEAT...AND OUT AHEAD OF A COLD FRONT
APPROACHING FROM THE W.
THE SHOWERS WILL CREATE MVFR CONDITIONS AT TIMES. IFR IS MOST
LIKELY IN ANY HEAVIER SHOWER OR THUNDERSTORM...AND IN THE WAKE OF
SHOWERS EARLY MON MORNING.
BKW WILL HAVE MVFR STRATUS IN GUSTY SE FLOW THROUGH THE PD.
OTHERWISE S TO SE SFC FLOW OVERNIGHT WILL BECOME GUSTY ON MON.
LIGHT S FLOW ALOFT WILL BECOME MODERATE S TO SW OVERNIGHT...AND THEN
LIGHT TO MODERATE S TO SW ON MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: AVIATION CONDITIONS ARE LIKELY TO VARY
OVERNIGHT INTO MON MORNING WITH THE APPROACH OF A WARM FRONT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/11/14
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H M H H H H H H
BKW CONSISTENCY M M M M L L M H H H M M
EKN CONSISTENCY H M M M M H H H M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z TUESDAY...
IFR CONDITIONS IN ROUNDS OF SHOWERS AND THUNDERSTORMS MON NT...POST
RAIN STRATUS TUE MORNING...AND ONE LAST ROUND OF THUNDERSTORMS LATER
TUE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/TRM
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS TULSA OK
644 PM CDT SUN AUG 10 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WEAK BOUNDARY HAS PUSHED INTO EAST CENTRAL OKLAHOMA EARLY THIS
EVENING WITH A FEW ISOLATED THUNDERSTORMS ONGOING. THIS ACTIVITY
WILL BEGIN TO SLOWLY DISSIPATE THIS EVENING WITH NO IMPACT EXPECTED
AT ANY TAF SITES. PATCHY LIGHT FOG WILL BE POSSIBLE ACROSS NW AR
TONIGHT...OTHERWISE VFR CONDITIONS ARE EXPECTED. NORTHERLY WINDS
WILL BEGIN TO INCREASE INTO MONDAY AS WEAK HIGH PRESSURE BUILDS
INTO THE REGION BEHIND FRONT.
&&
.PREV DISCUSSION... /ISSUED 311 PM CDT SUN AUG 10 2014/
DISCUSSION...
THE PATTERN ALOFT IS CURRENTLY UNDERGOING AMPLIFICATION IN THE
HIGHER LATITUDES...WITH A SPLIT FLOW BLOCK ALONG THE WEST COAST
AND A TROUGH NOW BEGINNING TO TAKE SHAPE OVER THE NORTHERN PLAINS
INTO THE GREAT LAKES. FARTHER SOUTH...A DISTURBANCE EVIDENT ON WV
IMAGERY OVER THE MID MISSOURI VALLEY WILL TRANSLATE SOUTHEAST
TOWARD THE MID MISSISSIPPI VALLEY BY 12Z MONDAY. AT THE
SURFACE...A WEAK BOUNDARY WILL SLIDE SOUTH ACROSS OUR REGION WITH
THE LEAD DISTURBANCE...WHILE THE REINFORCING PUSH OF SOME COOLER
AND DRIER AIR IN ASSOCIATION WITH THE DEVELOPING GREAT LAKES UPPER
TROUGH ARRIVES LATE TONIGHT INTO MONDAY. THE LATEST HI-RES SHORT
TERM MODELS INCLUDING THE HRRR AND LOCAL WRF ARE NOT VERY EXCITED
IN DEVELOPING CONVECTION THIS EVENING AND OVERNIGHT IN ADVANCE OF
THE BOUNDARY. THE BETTER CHANCES WILL BE OVER THE OZARKS AND OVER
SOUTHEAST OKLAHOMA...WITH SCATTERED POPS MAINTAINED IN THE GRIDS.
RAIN CHANCES WILL QUICKLY BE USHERED OUT OF HERE FROM NORTH TO
SOUTH LATE TONIGHT INTO MONDAY AS THE COOLER...DRIER AIR WORKS ITS
WAY IN.
MUCH OF THE WORK WEEK LOOKS RATHER PLEASANT...ESPECIALLY TUESDAY
AND WEDNESDAY...WITH HIGHS FALLING BACK INTO THE 80S AND LOWS
DROPPING BACK INTO THE 60S AND EVEN 50S IN THE COOLER SPOTS. NICE
PREVIEW OF FALL I WOULD SAY. THE HEAT AND HUMIDITY WILL GRADUALLY
RETURN BY NEXT WEEKEND. MODELS HAVE NOT HAD GOOD RUN TO RUN
CONSISTENCY DURING THIS TIME ON HOW THE PATTERN WILL EVOLVE.
TODAY`S RUNS BRING A DISTURBANCE SOUTHEAST ACROSS THE CENTRAL
PLAINS ON THE EASTERN FRINGES OF A SOUTHERN HI PLAINS RIDGE AND
THUS THERE WILL BE SOME POTENTIAL FOR RAIN BY NEXT WEEKEND AS WELL.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...12
AREA FORECAST DISCUSSION
NWS PENDLETON OR
823 PM PDT SUN AUG 10 2014
.UPDATE...THUNDERSTORMS HAVE DEVELOPED IN THE SOUTHERN FRINGE OF
THE FORECAST AREA THIS EVENING WITH THE BULK OF THE ACTIVITY IN
DESCHUTES COUNTY SOUTH OF BEND. THUNDERSTORMS HAVE NOT BEEN
PARTICULARLY STRONG AND APPEAR TO BE WEAKENING AS SUNDOWN
APPROACHES. HOWEVER, THE LATEST RUN OF THE HRRR MODEL SHOWS
ANOTHER BAND OF THUNDERSTORMS ARRIVING IN DESCHUTES COUNTY FROM
THE SOUTH AROUND MIDNIGHT. THUNDERSTORMS ARE SHOWN MOVING AS FAR
NORTH AS NORTHERN JEFFERSON COUNTY A COUPLE OF HOURS LATER SO HAVE
EXPANDED THE AREA OF ISOLATED THUNDERSTORMS OVERNIGHT FURTHER
NORTH. HAVE ALSO ADJUSTED SKY COVER TO MATCH CURRENT TRENDS AND
THE POSSIBLE THUNDERSTORMS LATER TONIGHT. FORECAST IS OTHERWISE IN
GOOD SHAPE. UPDATE WILL BE OUT SHORTLY. PERRY
&&
.PREV DISC... /ISSUED 337 PM PDT SUN AUG 10 2014/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. CUMULUS STARTING TO
FORM OVER THE HIGHER TERRAIN OF CENTRAL AND NORTHEAST OREGON EARLY
THIS AFTERNOON. IF THE TREND CONTINUES SHOULD SEE ISOLATED SHOWERS
AND THUNDERSTORMS DEVELOP LATE AFTERNOON INTO THE EVENING. THIS IS
IN RESPONSE TO A LARGE UPPER LOW JUST OFF THE CALIFORNIA COAST AND
INCREASING INSTABILITY. 18Z NAM INDICATES SOME ACTIVITY COULD
CONTINUE OVERNIGHT FOR CENTRAL OREGON. NORTH OF THIS AREA SKIES
SHOULD REMAIN MOSTLY CLEAR THROUGH THE EVENING AND TONIGHT. THE
UPPER LOW REMAINS NEARLY STATIONARY ALONG THE CALIFORNIA COAST
MONDAY HOWEVER THE UPPER LEVEL FLOW BECOMES MORE SOUTHERLY OVER OUR
FORECAST AREA. THIS SHOULD ALLOW CONVECTION TO MOVE NORTHWARD DURING
THE DAY AND INTO MONDAY NIGHT. MORE ENHANCEMENT FROM THE JET COULD
PRODUCE SOME STRONGER STORMS TOMORROW AS WELL. THE LOW WEAKENS A BIT
AND MOVES NORTHEAST ACROSS THE REGION TUESDAY AND SHOULD BRING MORE
WIDESPREAD SHOWERS AND THUNDERSTORMS. ON WEDNESDAY ANOTHER UPPER LOW
MOVES ACROSS THE PACIFIC NORTHWEST WITH ADDITIONAL SHOWERS AND
STORMS. AS FOR TEMPERATURES MONDAY WILL BE HOT WITH 90S TO NEAR 100.
COOLER TUESDAY WITH 80S TO LOWER 90S. EVEN COOLER WEDNESDAY WITH 70S
AND 80S. 94
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY NIGHT...A CLOSED UPPER
LEVEL LOW IS PROGGED TO SLOWLY MOVE EAST ACROSS THE AREA WEDNESDAY
NIGHT AND BE MAINLY OUT OF THE AREA BY EARLY SATURDAY MORNING. THIS
WILL RESULT IN A MUCH WETTER PERIOD DURING THE EXTENDED RANGE WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. GIVEN THE POTENTIAL PROJECTED PRECIPITATION WITH THE SYSTEM
AS IT PASSES THROUGH...THERE IS GOING TO BE SOME FLASH FLOOD
CONCERNS OVER THE NUMEROUS BURN SCARS WITHIN THE CWA IF ANY STORMS
DEVELOP AND TRANSITION OVER THOSE AREAS. THIS WILL NEED TO BE
MONITORED AS THE EVENT APPROACHES. WRAP AROUND MOISTURE MAY LINGER
BEHIND THE SYSTEM TO BRING SOME SHOWERS TO THE NORTHERN BLUE AND
WALLOWA MOUNTAINS EARLY FRIDAY MORNING BEFORE MOISTURE CLEARS OUT OF
THE AREA BY SATURDAY MORNING. A BRIEF SHORTWAVE RIDGE NUDGES INTO
THE AREA SATURDAY AND SUNDAY FOR A BRIEF DRYING TREND BEFORE MORE
MOISTURE AHEAD OF A POTENTIAL SHORTWAVE TROUGH ENCROACHES SUNDAY
EVENING. HIGH TEMPERATURES DURING THE PERIOD WILL BE IN THE MID 70S
TO MID 80S EXCEPT MID 60S TO MID 70S MOUNTAINS ON WEDNESDAY WITH
TEMPERATURES WARMING BACK UP INTO THE MID 70S TO UPPER 80S BY SUNDAY
AFTERNOON. BIEDA
AVIATION...00Z TAFS...UPPER LEVEL LOW OFF THE CENT CA COAST
CONTINUES TO PULL IN MOISTURE WHILE INCREASING INSTABILITY. ISOLD
THUNDERSTORMS HAVE DEVELOPED NEAR KBDN AND KRDM AND WILL CONTINUE
THRU 11/05Z. A BREAK IN ACTIVITY WILL OCCUR BTWN 11/05Z THRU 11/20Z
AFTER WHICH MORE THUNDERSTORMS WILL BREAK OUT OVER CENTRAL AND
NORTHEAST OREGON MOUNTAINS. VCTS IS INDICATED ON TAF SITES WITH
HIGHER CHANCES OF ACTIVITY. WINDS ARE EXPECTED TO BE AOB 12 KTS
DURING THE TAF PERIOD. BIEDA
FIRE WX...A LOW PRESSURE SYSTEM OFF THE COAST OF NORTHERN
CALIFORNIA WILL CONTINUE TO BRING MOISTURE FURTHER NORTH INTO THE
REGION EACH DAY. THIS WILL LEAD TO INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS. A RED FLAG WARNING FOR CENTRAL OREGON AND THE
SOUTHERN BLUE AND STRAWBERRY MOUNTAINS IS IN EFFECT STARTING THIS
AFTERNOON AND RUNNING THROUGH TUESDAY EVENING. THE CHANCE OF
THUNDERSTORMS WILL SPREAD NORTH AND EASTWARD ON MONDAY. THEREFORE A
RED FLAG WARNING HAS BEEN ISSUED STARTING MONDAY LATE MORNING AND
RUNNING THROUGH TUESDAY EVENING FOR THE EAST SLOPES OF THE OREGON
AND WASHINGTON CASCADES AND NORTHEAST OREGON MOUNTAINS. A FIRE
WEATHER WATCH REMAINS FOR THE COLUMBIA BASIN FOR THE POTENTIAL OF
THUNDERSTORMS MONDAY EVENING THROUGH TUESDAY. THESE THUNDERSTORMS
WILL START OUT WITH LITTLE TO NO RAINFALL. EXPECT PRECIPITATION
CHANCES TO INCREASE MONDAY AND TUESDAY. A TROUGH OF LOW PRESSURE
WILL MOVE INTO THE REGION TUESDAY INTO WEDNESDAY...WITH BREEZY WINDS
EXPECTED IN THE CASCADE GAPS TUESDAY AND WEDNESDAY AFTERNOONS. THE
POTENTIAL FOR THUNDERSTORMS WILL CONTINUE THROUGH THE MIDWEEK AS THE
TROUGH SLOWLY MOVES THROUGH THE REGION. DMH
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 64 99 70 88 / 0 10 20 30
ALW 66 100 72 90 / 0 10 20 30
PSC 62 102 69 92 / 0 10 20 30
YKM 60 99 71 87 / 0 10 20 30
HRI 60 100 68 91 / 0 10 20 30
ELN 59 99 67 88 / 0 10 20 30
RDM 57 93 61 85 / 20 30 30 40
LGD 57 94 61 86 / 10 30 30 40
GCD 59 95 60 86 / 20 30 30 40
DLS 63 100 70 87 / 0 20 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY ORZ041.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ506-509-511.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
ORZ049-050-502-503-507.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
ORZ041-044-503-507-508-510.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ505-510.
WA...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
WAZ024-520-521.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY WAZ030.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
WAZ024-026>029-521.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/98/98/84
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
859 PM CDT SUN AUG 10 2014
.DISCUSSION...00Z UPPER AIR ANALYSIS THIS EVENING PLACES A 500 MB
MID LEVEL TROUGH AXIS LOCATED ACROSS THE UPPER MIDWEST AND
PORTIONS OF MISSOURI AND EAST KANSAS. REGIONAL WSR-88D RADAR
TRENDS INDICATE INCREASED COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST MISSOURI
AND NORTH CENTRAL ARKANSAS THIS EVENING IN RESPONSE TO THIS MID
LEVEL SHORTWAVE TROUGH. LATEST MESOANALYSIS YIELDS SURFACE BASED CAPE
VALUES AROUND BETWEEN 2000-2500 J/KG...SURFACE BASED LI/S AROUND
-6. LATEST SHORT TERM TRENDS INCLUDING THE 11/00Z HRRR RUN
INDICATE A POTENTIAL FOR UPSTREAM SHOWERS AND THUNDERSTORMS TO
MOVE INTO PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL IN THE NEXT FEW HOURS AND SPREAD ACROSS THE REMAINDER OF
THE MID SOUTH OVERNIGHT. WILL MAKE ADJUSTMENTS TO RAIN CHANCES TO
ACCOUNT FOR SHORT TERM CONVECTIVE TRENDS AND ADJUST ANY OTHER
ELEMENTS AS NEEDED.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 624 PM CDT SUN AUG 10 2014/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 316 PM CDT SUN AUG 10 2014/
A STATIONARY FRONT CURRENTLY STRETCHES ACROSS SOUTHERN MISSOURI
THIS AFTERNOON. THIS FRONT WILL SLIDE INTO THE MIDSOUTH ON MONDAY
AS A COLD FRONT. SHOWERS AND THUNDERSTORMS ARE BEGINNING TO FIRE
ALONG THE FRONT. THESE SHOWERS AND THUNDERSTORMS MAY DEVELOP INTO
A LINE LATER THIS EVENING. THE LINE MAY BEGIN TO PUSHING INTO
NORTHEAST ARKANSAS LATE TONIGHT INTO THE EARLY MORNING HOURS.
MEANWHILE...EXPECT DIURNAL SHOWERS AND THUNDERSTORMS THAT ARE CURRENTLY
OCCURRING NEAR THE TENNESSEE RIVER AND ACROSS NORTHWEST
MISSISSIPPI TO DIE OUT DURING THE EARLY EVENING HOURS. ANOTHER
HUMID NIGHT IS EXPECTED ACROSS THE MIDSOUTH. LOWS WILL BE IN THE
LOWER TO MID 70S.
EXPECT SOME LINGERING CONVECTION MONDAY MORNING ACROSS NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL AND WEST TENNESSEE FROM IS LEFT
OF LINE THAT MOVES IN DURING THE OVERNIGHT HOURS AHEAD OF THE
APPROACHING COLD FRONT. REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS
WILL OCCUR ALONG THE COLD FRONT MONDAY AFTERNOON. SOME STORMS MAY
BECOME SEVERE PRODUCING LARGE HAIL...DAMAGING WINDS...AND FLASH
FLOODING. HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S.
THE COLD FRONT WILL CONTINUE TO PUSH SOUTHWARD MONDAY NIGHT.
LINGERING CHANCES FOR SHOWERS AND THUNDERSTORMS WILL OCCUR MAINLY
ACROSS WEST TENNESSEE NEAR THE MISSISSIPPI BORDER INTO NORTH
MISSISSIPPI. COOLER AND DRIER AIR MAY BEGIN TO FILTER INTO THE
MISSOURI BOOTHEEL...NORTHEAST ARKANSAS...AND NORTHWEST TENNESSEE
DURING THE EARLY MORNING HOURS.
TUESDAY THROUGH FRIDAY WILL BE BEAUTIFUL ACROSS THE MIDSOUTH. SFC
HIGH PRESSURE WILL MOVE INTO THE AREA FROM THE UPPER MIDWEST. EXPECT
COOLER TEMPERATURES WITH LOW HUMIDITY AND PLENTY OF SUNSHINE.
HIGHS WILL BE IN THE 80S WITH LOWS IN THE MID 50S TO MID 60S.
PATTERN BECOMES UNSETTLED ONCE AGAIN BY NEXT WEEKEND AS SFC HIGH
SHIFTS EAST. WEAK NORTHWEST FLOW ALOFT WILL ALLOW A COUPLE OF
DISTURBANCES TO MOVE THROUGH THE REGION SETTING OFF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. HUMIDITY WILL ALSO RETURN TO
THE AREA.
KRM
&&
.AVIATION...
00Z TAF CYCLE
NO THUNDERSTORMS ARE EXPECTED AT ANY TAF SITE FOR THE NEXT SEVERAL
HOURS. EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD ALTHOUGH
SOME MVFR CIGS AND VIS IS POSSIBLE LATE TONIGHT/EARLY TOMORROW.
AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL APPROACH THE
REGION LATER TONIGHT AND MONDAY MORNING. AS A RESULT EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP THOUGH TIMING IS A
PROBLEM SO OPTED TO CONTINUE VCTS FOR NOW STARTING LATER TONIGHT.
EXPECT SOME LIGHT FOG AT KMKL AND KTUP LATER TONIGHT. WINDS WILL
BE GENERALLY LIGHT FROM THE SW/WSW.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
706 PM CDT SUN AUG 10 2014
.UPDATE...FOR 00Z TAFS.
&&
.AVIATION...
LOW-LEVEL MOISTURE EXPECTED TO REMAIN HIGH OVER THE NEXT DAY OR
TWO...AND THAT WILL CONTINUE TREND OF SCATTERED STORMS AND LATE
NIGHT FOG/LOW CIGS. CKV/CSV AGAIN BEST CHANCE FOR MVFR/IFR
CONDITIONS OVERNIGHT. CONDITIONS EXPECTED TO BE VFR ALL SITES BY
15Z MON BUT PASSING STORM MAY BRIEFLY LOWER AT TIMES... ESPECIALLY
IN THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 630 PM CDT SUN AUG 10 2014/
DISCUSSION...
MOIST CONDITIONS CONTINUE ACROSS THE MID STATE THIS AFTERNOON WITH
DEWPOINTS GENERALLY IN THE LOWER 70S. LAST NIGHT...FOG DID FORM
ACROSS MUCH OF THE AREA. A COMPARISON OF EXPECTED 12Z DEWPOINT
DEPRESSIONS TO THAT OF THIS MORNING REVEALS THAT IT WILL BE ONLY
SLIGHTLY DRIER. THEREFORE...WILL GO AHEAD AND INCLUDE PATCHY FOG
AFTER 06Z.
OTHERWISE...CONVECTION IS CURRENTLY QUITE LIMITED AT THIS TIME. WE
DO SEE AN AREA OF CONVECTION DEVELOPING ACROSS MO. HRRR AS WELL AS
A VARIETY OF MODEL SOLUTIONS DO EXPECTED THIS AREA TO HOLD
TOGETHER OVERNIGHT WITH THE CONVECTION REACHING OUR NW CORNER
AROUND 06Z. AFTERWARD...IT DOES LOOK LIKE UPPER DIVERGENCE FIELDS
WILL WEAKEN AFTER MIDNIGHT WITH THE MAIN MID LEVEL SHORTWAVE AXIS
ORIENTED UPSTREAM A GOOD WAYS.
SO...FOR THE FCST...WILL SLIGHTLY LOWER EVENING POPS ACROSS THE
NORTHWEST HALF. OTW...KEEP POPS AS IS THEREAFTER...WITH A CHANCE
OF SHOWERS AND TSTMS THROUGH 12Z. WILL ADD PATCHY FOG FOR THE POST
06Z PERIOD. REMAINDER OF FCST LOOKS TO BE IN GOOD SHAPE. A SEASONABLY
HUMID NIGHT FOR EARLY/MID AUGUST IS IN STORE.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 303 PM CDT SUN AUG 10 2014/
DISCUSSION...THE ATMOSPHERE REMAINS VERY MOIST OVER MID TN THIS
AFTERNOON. IN SPITE OF THICK EARLY MORNING CLOUDS...SUNSHINE HAS
BROKEN THROUGH AND TEMPS HAVE REACHED OR EXCEEDED EXPECTED LEVELS
THIS AFTERNOON. A WEAK SURFACE LOW CONTINUES TO SIT OVER THE
REGION...CENTERED ROUGHLY OVER LOUISVILLE. NO OTHER MAJOR FORCING
MECHANISMS WERE NOTED...SO THE FORECAST FOR AROUND 30 PERCENT
COVERAGE OF THUNDERSTORMS WILL CONTINUE INTO THIS EVENING. ANY
STORMS COULD BE STRONG WITH HEAVY DOWNPOURS AND LOCALIZED STREET
FLOODING.
CONVECTION SHOULD DIMINISH LATE THIS EVENING...BUT ADDITIONAL
STORMS ARE EXPECTED TO DEVELOP LATER IN THE NIGHT AS ANOTHER WAVE
APPROACHES...AND UPPER LEVEL WINDS BECOME INCREASINGLY DIFLUENT.
OTHERWISE...EXPECT A MUGGY NIGHT WITH SOME AREAS OF LATE NIGHT
STRATUS AND FOG.
FOR MONDAY INTO MONDAY NIGHT...THE ATMOSPHERE WILL BE LOADED WITH
MOISTURE AND MODERATE INSTABILITY AS A TROUGH AND SURFACE FRONT
APPROACH. THUNDERSTORMS ARE LIKELY MONDAY THROUGH MONDAY
EVENING...ESPECIALLY LATE AFTERNOON AND EVENING WHEN PEAK HEATING
AND SURFACE FORCING WILL BE THE STRONGEST. FORECAST SOUNDINGS
POINT TO SOME STRONG STORMS WITH LOCALIZED VERY HEAVY DOWNPOURS.
AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS WILL LINGER INTO TUESDAY
AS THE MAIN SURFACE BOUNDARY CONTINUES TO PUSH ACROSS THE AREA.
THE GREATEST CHANCE WILL BE EAST OF I 65.
COOLER AND DRIER AIR WILL MOVE IN FOR MIDWEEK WITH A LEAST A
COUPLE OF DAYS OF BELOW NORMAL TEMPERATURES. MOST SPOTS WILL BE
IN THE 50S LATE WEDNESDAY NIGHT. HIGHS WEDNESDAY AND THURSDAY WILL
BE IN THE LOW TO MID 80S...WITH 70S ON THE PLATEAU. HUMIDITY
LEVELS WILL BE QUITE PLEASANT FOR AUGUST WITH DEW POINTS IN THE
50S.
LATE WEEK WILL BRING DEVELOPING SOUTHERLY LOW LEVEL WINDS AS
AN IMPULSE APPROACHES FROM THE WEST NORTHWEST. THIS WILL MEAN A
RETURN TO NORMAL TEMPS AND HUMIDITY AND A CHANCE FOR
THUNDERSTORMS FOR NEXT WEEKEND.
13
PREV DISCUSSION... /ISSUED 154 PM CDT SUN AUG 10 2014/
UPDATE...FOR 18Z TAFS
AVIATION...
JUST A FEW SHOWERS AND THUNDERSTORMS AROUND THE AREA THIS
AFTERNOON. THE POTENTIAL FOR SHOWERS WILL INCREASE SLIGHTLY AS WE
GO THROUGHOUT THE NIGHT AND THE WEAK SURFACE LOW TO OUR NORTH
STRENGTHENS. FOG IS LIKELY AT ALL SITES EARLY MONDAY
MORNING...WITH AT LEAST IFR VIS AT CSV AND MVFR VIS LIKELY AT BNA
AND CKV. SHOWER AND THUNDERSTORM CHANCES WILL INCREASE FROM THE
WEST FROM 12Z THROUGH 18Z TOMORROW. NOT EXPECTING SEVERE
WEATHER...BUT HEAVY DOWNPOURS AND GUSTY WINDS WILL BE POSSIBLE WITH
SOME STORMS ESPECIALLY AS WE APPROACH THE AFTERNOON HOURS. CIGS
WILL BE BORDERLINE VFR/MVFR CRITERIA FOR MOST OF THE FORECAST
PERIOD...WITH FALLING CIGS TO AROUND 700FT EARLY MONDAY MORNING AT
CSV.
11
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
630 PM CDT SUN AUG 10 2014
.DISCUSSION...
MOIST CONDITIONS CONTINUE ACROSS THE MID STATE THIS AFTERNOON WITH
DEWPOINTS GENERALLY IN THE LOWER 70S. LAST NIGHT...FOG DID FORM
ACROSS MUCH OF THE AREA. A COMPARISON OF EXPECTED 12Z DEWPOINT
DEPRESSIONS TO THAT OF THIS MORNING REVEALS THAT IT WILL BE ONLY
SLIGHTLY DRIER. THEREFORE...WILL GO AHEAD AND INCLUDE PATCHY FOG
AFTER 06Z.
OTHERWISE...CONVECTION IS CURRENTLY QUITE LIMITED AT THIS TIME. WE
DO SEE AN AREA OF CONVECTION DEVELOPING ACROSS MO. HRRR AS WELL AS
A VARIETY OF MODEL SOLUTIONS DO EXPECTED THIS AREA TO HOLD
TOGETHER OVERNIGHT WITH THE CONVECTION REACHING OUR NW CORNER
AROUND 06Z. AFTERWARD...IT DOES LOOK LIKE UPPER DIVERGENCE FIELDS
WILL WEAKEN AFTER MIDNIGHT WITH THE MAIN MID LEVEL SHORTWAVE AXIS
ORIENTED UPSTREAM A GOOD WAYS.
SO...FOR THE FCST...WILL SLIGHTLY LOWER EVENING POPS ACROSS THE
NORTHWEST HALF. OTW...KEEP POPS AS IS THEREAFTER...WITH A CHANCE
OF SHOWERS AND TSTMS THROUGH 12Z. WILL ADD PATCHY FOG FOR THE POST
06Z PERIOD. REMAINDER OF FCST LOOKS TO BE IN GOOD SHAPE. A SEASONABLY
HUMID NIGHT FOR EARLY/MID AUGUST IS IN STORE.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 303 PM CDT SUN AUG 10 2014/
DISCUSSION...THE ATMOSPHERE REMAINS VERY MOIST OVER MID TN THIS
AFTERNOON. IN SPITE OF THICK EARLY MORNING CLOUDS...SUNSHINE HAS
BROKEN THROUGH AND TEMPS HAVE REACHED OR EXCEEDED EXPECTED LEVELS
THIS AFTERNOON. A WEAK SURFACE LOW CONTINUES TO SIT OVER THE
REGION...CENTERED ROUGHLY OVER LOUISVILLE. NO OTHER MAJOR FORCING
MECHANISMS WERE NOTED...SO THE FORECAST FOR AROUND 30 PERCENT
COVERAGE OF THUNDERSTORMS WILL CONTINUE INTO THIS EVENING. ANY
STORMS COULD BE STRONG WITH HEAVY DOWNPOURS AND LOCALIZED STREET
FLOODING.
CONVECTION SHOULD DIMINISH LATE THIS EVENING...BUT ADDITIONAL
STORMS ARE EXPECTED TO DEVELOP LATER IN THE NIGHT AS ANOTHER WAVE
APPROACHES...AND UPPER LEVEL WINDS BECOME INCREASINGLY DIFLUENT.
OTHERWISE...EXPECT A MUGGY NIGHT WITH SOME AREAS OF LATE NIGHT
STRATUS AND FOG.
FOR MONDAY INTO MONDAY NIGHT...THE ATMOSPHERE WILL BE LOADED WITH
MOISTURE AND MODERATE INSTABILITY AS A TROUGH AND SURFACE FRONT
APPROACH. THUNDERSTORMS ARE LIKELY MONDAY THROUGH MONDAY
EVENING...ESPECIALLY LATE AFTERNOON AND EVENING WHEN PEAK HEATING
AND SURFACE FORCING WILL BE THE STRONGEST. FORECAST SOUNDINGS
POINT TO SOME STRONG STORMS WITH LOCALIZED VERY HEAVY DOWNPOURS.
AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS WILL LINGER INTO TUESDAY
AS THE MAIN SURFACE BOUNDARY CONTINUES TO PUSH ACROSS THE AREA.
THE GREATEST CHANCE WILL BE EAST OF I 65.
COOLER AND DRIER AIR WILL MOVE IN FOR MIDWEEK WITH A LEAST A
COUPLE OF DAYS OF BELOW NORMAL TEMPERATURES. MOST SPOTS WILL BE
IN THE 50S LATE WEDNESDAY NIGHT. HIGHS WEDNESDAY AND THURSDAY WILL
BE IN THE LOW TO MID 80S...WITH 70S ON THE PLATEAU. HUMIDITY
LEVELS WILL BE QUITE PLEASANT FOR AUGUST WITH DEW POINTS IN THE
50S.
LATE WEEK WILL BRING DEVELOPING SOUTHERLY LOW LEVEL WINDS AS
AN IMPULSE APPROACHES FROM THE WEST NORTHWEST. THIS WILL MEAN A
RETURN TO NORMAL TEMPS AND HUMIDITY AND A CHANCE FOR
THUNDERSTORMS FOR NEXT WEEKEND.
13
PREV DISCUSSION... /ISSUED 154 PM CDT SUN AUG 10 2014/
UPDATE...FOR 18Z TAFS
AVIATION...
JUST A FEW SHOWERS AND THUNDERSTORMS AROUND THE AREA THIS
AFTERNOON. THE POTENTIAL FOR SHOWERS WILL INCREASE SLIGHTLY AS WE
GO THROUGHOUT THE NIGHT AND THE WEAK SURFACE LOW TO OUR NORTH
STRENGTHENS. FOG IS LIKELY AT ALL SITES EARLY MONDAY
MORNING...WITH AT LEAST IFR VIS AT CSV AND MVFR VIS LIKELY AT BNA
AND CKV. SHOWER AND THUNDERSTORM CHANCES WILL INCREASE FROM THE
WEST FROM 12Z THROUGH 18Z TOMORROW. NOT EXPECTING SEVERE
WEATHER...BUT HEAVY DOWNPOURS AND GUSTY WINDS WILL BE POSSIBLE WITH
SOME STORMS ESPECIALLY AS WE APPROACH THE AFTERNOON HOURS. CIGS
WILL BE BORDERLINE VFR/MVFR CRITERIA FOR MOST OF THE FORECAST
PERIOD...WITH FALLING CIGS TO AROUND 700FT EARLY MONDAY MORNING AT
CSV.
11
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1253 PM CDT SAT AUG 9 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 1045 AM CDT SAT AUG 9 2014/
UPDATE...
AREAS OF SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE SOUTHEAST OVER
WEST TENNESSEE NEAR THE TENNESSEE RIVER...NORTH MISSISSIPPI AND
EASTERN ARKANSAS. LATEST HRRR AND 12Z NAM INDICATE THAT ONCE THIS
ACTIVITY SHIFTS SOUTH AND EAST INTO CENTRAL MISSISSIPPI AND
ALABAMA THAT IT MAY BE IT FOR CONVECTION FOR AT LEAST THE REST OF
THE AFTERNOON. WILL UPDATE TO LOWER POPS FOR THE AFTERNOON HOURS.
MAY ALSO LOWER HIGHS A TAD ACROSS NORTH MISSISSIPPI DUE TO
CONVECTION AND CLOUD COVER.
KRM
DISCUSSION... /ISSUED 405 AM CDT SAT AUG 9 2014/
IT WAS A QUIET NIGHT WEATHERWISE EARLY THIS MORNING WITH ONLY A
FEW LIGHT SHOWERS. SKIES WERE MOSTLY CLOUDY WITH TEMPERATURES IN
THE 70S. WINDS WERE LIGHT.
A WEAK COLD FRONT WILL EDGE INTO NORTHEAST AR...THE MO BOOTHEEL AND
NORTHWEST TN FROM THE NORTHWEST TODAY. UPPER LEVEL HEIGHTS REMAIN
BELOW NORMAL WITH THE MIDSOUTH IN A WEAK WEST TO NORTHWEST WIND FLOW
ALOFT. THE ATMOSPHERE CONTINUES VERY MOIST WITH THE 00Z LITTLE ROCK
SOUNDING HAVING A PRECIPITABLE WATER VALUE OF 2.14 INCHES. THE
ATMOSPHERE WILL BECOME VERY UNSTABLE AGAIN TODAY WITH DAYTIME
HEATING ALTHOUGH MIDDLE LEVEL LAPSE RATES WILL REMAIN POOR.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP ONCE AGAIN. A FEW STRONG TO SEVERE THUNDERSTORMS ARE
POSSIBLE. STRONG GUSTY WINDS AND HEAVY RAINFALL RESULTING IN FLASH
FLOODING MAY OCCUR. IT WILL BE VERY WARM AND HUMID WITH SOME COOLING
FROM THE SHOWERS AND THUNDERSTORMS.
THE WEAK COLD FRONT WILL GRADUALLY WASH OUT ACROSS THE MIDSOUTH
THROUGH SUNDAY AS IT SINKS A LITTLE FURTHER SOUTH. DRIER AIR ALOFT
WILL SPREAD INTO THE REGION FROM THE NORTH. THUS LESS CONVECTION IS
EXPECTED SUNDAY WITH HOTTER TEMPERATURES. HEAT INDEX READINGS SUNDAY
AFTERNOON ARE EXPECTED TO CLIMB TO BETWEEN 100 AND 104 DEGREES
ACROSS A LARGE SECTION OF THE MIDSOUTH. WILL STILL HAVE THE THREAT
OF A FEW STRONG TO SEVERE THUNDERSTORMS WITH STRONG GUSTY WINDS
ALONG WITH LOCALLY HEAVY RAINFALL AND POSSIBLE FLASH FLOODING.
SUNDAY NIGHT...A STRONG UPPER LEVEL SHORT WAVE WILL MOVE THROUGH THE
MIDDLE MS RIVER VALLEY HELPING TO PUSH A STRONGER COLD FRONT
SOUTHWARD TOWARD THE MIDSOUTH. THIS COLD FRONT WILL APPROACH THE
MIDSOUTH FROM THE NORTHWEST BY LATE SUNDAY NIGHT THEN MOVE THROUGH
THE REGION MONDAY. THIS WILL CAUSE AN INCREASE IN THE CHANCE OF
SHOWERS AND THUNDERSTORMS. A FEW STRONG TO SEVERE THUNDERSTORMS WILL
BE POSSIBLE ALONG WITH HEAVY RAINFALL AND LOCALIZED FLASH FLOODING.
KEPT POPS AT 50 PERCENT MONDAY...BUT THIS MAY NEED TO BE INCREASED
IN LATER FORECASTS.
LATEST MODELS ARE MOVING THIS STRONGER COLD FRONT THROUGH THE
MIDSOUTH A LITTLE FASTER THAN EARLIER INDICATED. TRIMMED THE POPS
BACK A LITTLE FROM THE NORTHWEST TUESDAY...AND THEY MAY NEED TO BE
TRIMMED BACK FURTHER IN LATER FORECASTS.
BY WEDNESDAY IF NOT A LITTLE SOONER...SOME GORGEOUS SUMMERTIME
WEATHER WILL ONCE AGAIN SET UP ACROSS THE MIDSOUTH FOR A FEW DAYS.
AN UPPER LEVEL RIDGE TO OUR WEST AND A DEEP UPPER LEVEL TROUGH OVER
THE NORTHEASTERN UNITED STATES WILL PLACE THE MIDSOUTH IN DRY
NORTHWESTERLY FLOW ALOFT. UNSEASONABLY MILD SURFACE HIGH PRESSURE
WILL SETTLE OVER THE MIDSOUTH FROM THE NORTH. LOWS WILL BE IN THE
60S...EVEN 50S ALONG THE TN RIVER VALLEY...WITH HIGHS IN THE 80S
ALONG WITH COMFORTABLE HUMIDITY.
SOME UNCERTAINTY ARRIVES IN THE FORECAST BY FRIDAY WITH MODELS
INDICATING VARYING SOLUTIONS AND PERHAPS SOME CHANCE OF RAIN. FOR
NOW KEPT THE FORECAST RAIN FREE.
JCL
&&
.AVIATION...
18Z TAF CYCLE
THIS MORNINGS ROUND OF SHRAS/TSRAS CONTINUES TO PUSH OFF TO THE
SOUTHEAST. LOOKS LIKE KTUP HAS THE BEST CHANCE FOR A TSRA THIS
AFTERNOON SO KEPT A VCTS OTRW THE REMAINDER OF AREA MAY REMAIN
QUIET. DECIDED TO REMOVE THE VCTS AT KMEM...KJBR AND KMKL.
LATEST MODELS GUIDANCE LOOKS FAIRLY QUIET OVERNIGHT AS WELL. THERE
MAY BE SOME ACTIVITY MOVING INTO THE DELTA THIS EVENING BUT
CONFIDENCE IS TOO LOW TO INCLUDE THAT IN THE TAFS. GIVEN THE
AMOUNT OF LOW CLOUDS AROUND THIS MORNING DECIDED TO PLACE SOME IFR
CONDS INTO THE TAFS LATE TONIGHT/EARLY SUNDAY SINCE THE PATTERN
WILL BE SIMILAR. WINDS WILL GENERALLY BE LIGHT THROUGH THE
PERIOD..MAINLY OUT OF THE WSW.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1045 AM CDT SAT AUG 9 2014
.UPDATE...
AREAS OF SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE SOUTHEAST OVER
WEST TENNESSEE NEAR THE TENNESSEE RIVER...NORTH MISSISSIPPI AND
EASTERN ARKANSAS. LATEST HRRR AND 12Z NAM INDICATE THAT ONCE THIS
ACTIVITY SHIFTS SOUTH AND EAST INTO CENTRAL MISSISSIPPI AND
ALABAMA THAT IT MAY BE IT FOR CONVECTION FOR AT LEAST THE REST OF
THE AFTERNOON. WILL UPDATE TO LOWER POPS FOR THE AFTERNOON HOURS.
MAY ALSO LOWER HIGHS A TAD ACROSS NORTH MISSISSIPPI DUE TO
CONVECTION AND CLOUD COVER.
KRM
&&
.DISCUSSION... /ISSUED 405 AM CDT SAT AUG 9 2014/
IT WAS A QUIET NIGHT WEATHERWISE EARLY THIS MORNING WITH ONLY A
FEW LIGHT SHOWERS. SKIES WERE MOSTLY CLOUDY WITH TEMPERATURES IN
THE 70S. WINDS WERE LIGHT.
A WEAK COLD FRONT WILL EDGE INTO NORTHEAST AR...THE MO BOOTHEEL AND
NORTHWEST TN FROM THE NORTHWEST TODAY. UPPER LEVEL HEIGHTS REMAIN
BELOW NORMAL WITH THE MIDSOUTH IN A WEAK WEST TO NORTHWEST WIND FLOW
ALOFT. THE ATMOSPHERE CONTINUES VERY MOIST WITH THE 00Z LITTLE ROCK
SOUNDING HAVING A PRECIPITABLE WATER VALUE OF 2.14 INCHES. THE
ATMOSPHERE WILL BECOME VERY UNSTABLE AGAIN TODAY WITH DAYTIME
HEATING ALTHOUGH MIDDLE LEVEL LAPSE RATES WILL REMAIN POOR.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP ONCE AGAIN. A FEW STRONG TO SEVERE THUNDERSTORMS ARE
POSSIBLE. STRONG GUSTY WINDS AND HEAVY RAINFALL RESULTING IN FLASH
FLOODING MAY OCCUR. IT WILL BE VERY WARM AND HUMID WITH SOME COOLING
FROM THE SHOWERS AND THUNDERSTORMS.
THE WEAK COLD FRONT WILL GRADUALLY WASH OUT ACROSS THE MIDSOUTH
THROUGH SUNDAY AS IT SINKS A LITTLE FURTHER SOUTH. DRIER AIR ALOFT
WILL SPREAD INTO THE REGION FROM THE NORTH. THUS LESS CONVECTION IS
EXPECTED SUNDAY WITH HOTTER TEMPERATURES. HEAT INDEX READINGS SUNDAY
AFTERNOON ARE EXPECTED TO CLIMB TO BETWEEN 100 AND 104 DEGREES
ACROSS A LARGE SECTION OF THE MIDSOUTH. WILL STILL HAVE THE THREAT
OF A FEW STRONG TO SEVERE THUNDERSTORMS WITH STRONG GUSTY WINDS
ALONG WITH LOCALLY HEAVY RAINFALL AND POSSIBLE FLASH FLOODING.
SUNDAY NIGHT...A STRONG UPPER LEVEL SHORT WAVE WILL MOVE THROUGH THE
MIDDLE MS RIVER VALLEY HELPING TO PUSH A STRONGER COLD FRONT
SOUTHWARD TOWARD THE MIDSOUTH. THIS COLD FRONT WILL APPROACH THE
MIDSOUTH FROM THE NORTHWEST BY LATE SUNDAY NIGHT THEN MOVE THROUGH
THE REGION MONDAY. THIS WILL CAUSE AN INCREASE IN THE CHANCE OF
SHOWERS AND THUNDERSTORMS. A FEW STRONG TO SEVERE THUNDERSTORMS WILL
BE POSSIBLE ALONG WITH HEAVY RAINFALL AND LOCALIZED FLASH FLOODING.
KEPT POPS AT 50 PERCENT MONDAY...BUT THIS MAY NEED TO BE INCREASED
IN LATER FORECASTS.
LATEST MODELS ARE MOVING THIS STRONGER COLD FRONT THROUGH THE
MIDSOUTH A LITTLE FASTER THAN EARLIER INDICATED. TRIMMED THE POPS
BACK A LITTLE FROM THE NORTHWEST TUESDAY...AND THEY MAY NEED TO BE
TRIMMED BACK FURTHER IN LATER FORECASTS.
BY WEDNESDAY IF NOT A LITTLE SOONER...SOME GORGEOUS SUMMERTIME
WEATHER WILL ONCE AGAIN SET UP ACROSS THE MIDSOUTH FOR A FEW DAYS.
AN UPPER LEVEL RIDGE TO OUR WEST AND A DEEP UPPER LEVEL TROUGH OVER
THE NORTHEASTERN UNITED STATES WILL PLACE THE MIDSOUTH IN DRY
NORTHWESTERLY FLOW ALOFT. UNSEASONABLY MILD SURFACE HIGH PRESSURE
WILL SETTLE OVER THE MIDSOUTH FROM THE NORTH. LOWS WILL BE IN THE
60S...EVEN 50S ALONG THE TN RIVER VALLEY...WITH HIGHS IN THE 80S
ALONG WITH COMFORTABLE HUMIDITY.
SOME UNCERTAINTY ARRIVES IN THE FORECAST BY FRIDAY WITH MODELS
INDICATING VARYING SOLUTIONS AND PERHAPS SOME CHANCE OF RAIN. FOR
NOW KEPT THE FORECAST RAIN FREE.
JCL
&&
.AVIATION...
12Z TAF CYCLE
A TRICKY FORECAST IN THE SHORT TERM DUE TO AN ALREADY UNSTABLE
ATMOSPHERE THIS MORNING. CURRENTLY A COLD FRONT EXTENDS FROM
SOUTHERN IL TO JUST NORTH OF JBR. SOUTH OF THIS BOUNDARY...-SHRA
AND -TSRA HAVE ALREADY POPPED AND ARE NEAR TAF SITES MKL AND MEM.
MVFR/IFR CEILINGS AT MEM...MKL...AND JBR WILL LIKELY CONTINUE
THROUGH AT LEAST 09/14Z OR PERSIST EVEN LONGER.
CURRENT THINKING IS THAT ONGOING CONVECTION WILL MOVE EASTWARD
OUT OF THE AREA AND CONDITIONS WILL IMPROVE TO VFR AT ALL SITES
FOR A FEW HOURS. BY EARLY AFTERNOON -TSRAS ARE EXPECTED TO
REDEVELOP...MAINLY SOUTH OF AND ALONG THE COLD FRONT. SHORT TERM
MODELS DO NOT HANDLE THE CURRENT CONDITIONS WELL...SO AMENDMENTS
MAY BE NEEDED THROUGH EARLY AFTERNOON FOR RAPIDLY EVOLVING
CONDITIONS AND RADAR TRENDS.
AC3
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1100 AM EDT SAT AUG 9 2014
.DISCUSSION...FORECAST ON TRACK. MINOR UPDATE TO DEW POINTS AND
HUMIDITY. VERY MOIST AIRMASS IN PLACE. CONVECTION EXPECTED TO
INCREASE IN THE AFTERNOON HOURS. SLOW MOVING CELLS WILL PRODUCE HEAY
RAINFALL. SON
PREVIOUS DISCUSSION:
SHORT TERM...(TODAY AND TONIGHT)...SHORTWAVE RIDGING IN PLACE PLUS
THE TYPICAL STABILIZATION OVERNIGHT...HAS LED TO VERY SPARSE
CONVECTION THIS MORNING. THIS RIDGING ALOFT FLATTENS LATER TODAY AND
THE WARM FRONT FROM NRN PLATEAU TO SE TN SHOULD AID IN INCREASED
CONVECTION BY THIS AFTERNOON. HOWEVER...ONLY THE POORLY PERFORMING
GFS MODEL IS VERY AGGRESSIVE IN HOW MUCH CONVECTION OCCURS EVEN THIS
AFTERNOON. THE RAP AND HRRR MODELS REALLY DON`T ADVERTISE MORE THAN
SCATTERED SHOWERS AND TSRA. HAD NO CHOICE BUT TO DOWNPLAY POPS FOR
THE MORNING HOURS...THEN BLEND INTO SIMILAR HIGHER POPS FOR THE
AFTERNOON HOURS.
EXPECT CONVECTION TO DIMINISH AFTER MIDNIGHT...WHICH WAS GENERALLY
THE TREND IN PREVIOUS POP GRIDS. ADDED SOME PATCHY FOG LATE TONIGHT
WHICH HAS A BETTER CHANCE TO DEVELOP THAN THIS MORNING.
A FEW STRONG TO MARGINALLY SEVERE STORMS COULD OCCUR THIS AFTERNOON
AND EVENING. AIR MASS WILL BE AT LEAST MODERATELY UNSTABLE
TODAY... BUT FORECAST SOUNDINGS SHOW LESS SHEAR TODAY THAN
YESTERDAY. SO MIGHT JUST SEE ISOLATED PULSE TYPE STRONG STORMS.
WILL MENTION THIS AND LOCALLY HEAVY RAINS IN OUR HAZARDOUS WEATHER
PRODUCT.
OTHERWISE...AIR MASS LOOKS TOO MOIST TO GO ANY HIGHER THAN NAM MOS
MAXES. GFS MOS MAXES PROBABLY TOO WARM BUT LOOKED GREAT FOR
TONIGHT`S MINS.
LONG TERM...(SUNDAY THROUGH FRIDAY)...WET PERIOD CONTINUES SUNDAY
THROUGH TUESDAY. SLOW MOVING SHORTWAVE WILL BE MOVING SLOWLY EAST
SUNDAY MORNING AND AFTERNOON. HIGHEST RAIN CHANCES EASTERN AND
NORTHERN AREAS. WEAK SURFACE LOW PRESSURE REMAINS OVER THE FORECAST
AREA. EVENING SHOWERS AND STORMS WILL GIVE WAY TO A BREAK IN
RAIN...THEN ANOTHER SHORTWAVE MOVES INTO TN VALLEY WITH BROAD UPPER
TROUGH OVER REGION MONDAY. WITH DAY TIME HEATING SHOWERS AND STORMS
LIKELY NORTHEAST SECTIONS. DRYING OUT MONDAY NIGHT. ON TUESDAY
SURFACE LOW DEEPENS TO THE NORTH AND A COLD FRONT MOVES INTO THE TN
VALLEY. SHOWERS AND STORMS INCREASE OUT AHEAD OF THE FRONT AND NEXT
SHORTWAVE. PRECIPITATION CHANCES THEN LOWER TUESDAY NIGHT AND
WEDNESDAY AS COLD FRONT MOVES THROUGH. DRIER NW FLOW LATER WEDNESDAY
THROUGH FRIDAY WITH NO RAIN EXPECTED. BELOW NORMAL TEMPERATURES
ENTIRE FORECAST PERIOD. HIGHS IN THE MID TO UPPER 70S MOUNTAINS AND
PARTS OF SW VA TO THE LOWER TO MID 80S LOWER ELEVATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 86 72 87 70 / 70 60 60 40
KNOXVILLE MCGHEE TYSON AIRPORT, TN 83 71 85 69 / 80 60 60 40
OAK RIDGE, TN 83 70 84 69 / 70 60 60 40
TRI CITIES AIRPORT, TN 80 67 82 65 / 80 60 70 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG/TD
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
404 AM EDT SAT AUG 9 2014
.SHORT TERM...(TODAY AND TONIGHT)...SHORTWAVE RIDGING IN PLACE
PLUS THE TYPICAL STABILIZATION OVERNIGHT...HAS LED TO VERY SPARSE
CONVECTION THIS MORNING. THIS RIDGING ALOFT FLATTENS LATER TODAY
AND THE WARM FRONT FROM NRN PLATEAU TO SE TN SHOULD AID IN
INCREASED CONVECTION BY THIS AFTERNOON. HOWEVER...ONLY THE POORLY
PERFORMING GFS MODEL IS VERY AGGRESSIVE IN HOW MUCH CONVECTION
OCCURS EVEN THIS AFTERNOON. THE RAP AND HRRR MODELS REALLY DON`T
ADVERTISE MORE THAN SCATTERED SHOWERS AND TSRA. HAD NO CHOICE BUT
TO DOWNPLAY POPS FOR THE MORNING HOURS...THEN BLEND INTO SIMILAR
HIGHER POPS FOR THE AFTERNOON HOURS.
EXPECT CONVECTION TO DIMINISH AFTER MIDNIGHT...WHICH WAS GENERALLY
THE TREND IN PREVIOUS POP GRIDS. ADDED SOME PATCHY FOG LATE TONIGHT
WHICH HAS A BETTER CHANCE TO DEVELOP THAN THIS MORNING.
A FEW STRONG TO MARGINALLY SEVERE STORMS COULD OCCUR THIS AFTERNOON
AND EVENING. AIR MASS WILL BE AT LEAST MODERATELY UNSTABLE
TODAY... BUT FORECAST SOUNDINGS SHOW LESS SHEAR TODAY THAN
YESTERDAY. SO MIGHT JUST SEE ISOLATED PULSE TYPE STRONG STORMS.
WILL MENTION THIS AND LOCALLY HEAVY RAINS IN OUR HAZARDOUS WEATHER
PRODUCT.
OTHERWISE...AIR MASS LOOKS TOO MOIST TO GO ANY HIGHER THAN NAM MOS
MAXES. GFS MOS MAXES PROBABLY TOO WARM BUT LOOKED GREAT FOR
TONIGHT`S MINS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)...WET PERIOD CONTINUES SUNDAY
THROUGH TUESDAY. SLOW MOVING SHORTWAVE WILL BE MOVING SLOWLY EAST
SUNDAY MORNING AND AFTERNOON. HIGHEST RAIN CHANCES EASTERN AND
NORTHERN AREAS. WEAK SURFACE LOW PRESSURE REMAINS OVER THE FORECAST
AREA. EVENING SHOWERS AND STORMS WILL GIVE WAY TO A BREAK IN
RAIN...THEN ANOTHER SHORTWAVE MOVES INTO TN VALLEY WITH BROAD UPPER
TROUGH OVER REGION MONDAY. WITH DAY TIME HEATING SHOWERS AND
STORMS LIKELY NORTHEAST SECTIONS. DRYING OUT MONDAY NIGHT. ON
TUESDAY SURFACE LOW DEEPENS TO THE NORTH AND A COLD FRONT MOVES
INTO THE TN VALLEY. SHOWERS AND STORMS INCREASE OUT AHEAD OF THE
FRONT AND NEXT SHORTWAVE. PRECIPITATION CHANCES THEN LOWER TUESDAY
NIGHT AND WEDNESDAY AS COLD FRONT MOVES THROUGH. DRIER NW FLOW
LATER WEDNESDAY THROUGH FRIDAY WITH NO RAIN EXPECTED. BELOW NORMAL
TEMPERATURES ENTIRE FORECAST PERIOD. HIGHS IN THE MID TO UPPER 70S
MOUNTAINS AND PARTS OF SW VA TO THE LOWER TO MID 80S LOWER
ELEVATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 86 72 87 70 / 70 60 60 40
KNOXVILLE MCGHEE TYSON AIRPORT, TN 83 71 85 69 / 80 60 60 40
OAK RIDGE, TN 83 70 84 69 / 70 60 60 40
TRI CITIES AIRPORT, TN 80 67 82 65 / 80 60 70 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG/TD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1126 PM CDT FRI AUG 8 2014
.UPDATE...AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 914 PM CDT FRI AUG 8 2014/
DISCUSSION...SURFACE ANALYSIS THIS EVENING PLACES A QUASI-
STATIONARY BOUNDARY OVER NORTHERN ARKANSAS...SOUTHEAST
MISSOURI...SOUTHERN ILLINOIS...WESTERN KENTUCKY...MIDDLE TENNESSEE
AND INTO ALABAMA. 00Z UPPER AIR ANALYSIS ALONG WITH LATEST WATER
VAPOR SATELLITE/WSR-88D VAD WIND PROFILE TRENDS INDICATE AT LEAST
A COUPLE OF SHORTWAVE TROUGHS OVER THE MISSISSIPPI VALLEY. THE
FIRST ONE LOCATED ACROSS THE LOWER MISSISSIPPI VALLEY AND A MORE
SUBTLE ONE OVER PORTIONS OF NORTHWEST ARKANSAS. SHOWERS AND
THUNDERSTORMS HAVE DECREASED IN COVERAGE CONSIDERABLY ACROSS THE
MID SOUTH THIS EVENING WHILE AN MESOSCALE CONVECTIVE SYSTEM /MCS/
MOVES ACROSS THE WESTERN HALF OF ARKANSAS THIS EVENING.
LATEST 00Z WRF HAS JUST STARTED TO ARRIVE AND THINK IT MAY BE
SOMEWHAT OVERDONE AND WILL THUS LEAN PRECIPITATION CHANCES
TOWARDS THE HRRR SINCE IT/S PERFORMED BETTER THAN THE WRF/GFS OVER
THE PAST COUPLE OF NIGHTS. NONETHELESS...ISOLATED TO PERHAPS
SCATTERED RAIN CHANCES SEEM JUSTIFIED GIVEN CURRENT TRENDS.
WILL UPDATE FORECAST TO ADJUST RAIN CHANCES...ADD PATCHY FOG...AND
ADJUST ALL OTHER ELEMENTS AS NEEDED.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 612 PM CDT FRI AUG 8 2014/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 317 PM CDT FRI AUG 8 2014/
THE UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH EARLY NEXT
WEEK. WEAK NORTHWEST FLOW ALOFT WILL ALLOW SEVERAL UPPER LEVEL
DISTURBANCES TO MOVE THROUGH REGION. IN ADDITION...A WEAK FRONT
WILL MOVE INTO THE AREA AND THEN WASH OUT OVER THE CWA BY THE END
OF THE WEEKEND. EXACT TIMING OF THE DISTURBANCES AND THE BETTER
CHANCES OF RAIN ARE HARD TO PINPOINT MUCH MORE THAN 12-24 HOURS
OFF.
CURRENT RADAR SHOWS NUMEROUS SHOWERS AND THUNDERSTORMS MOVING
THROUGH WEST TENNESSEE NEAR THE TENNESSEE RIVER AND NORTH
MISSISSIPPI. A SECOND AREA OF SHOWERS AND THUNDERSTORMS ARE
FORMING ACROSS NORTHEAST ARKANSAS. BOTH AREAS SHOULD PUSH EAST
INTO MIDDLE TENNESSEE AND NORTH ALABAMA BETWEEN 5-8 PM.
THEREAFTER...A LULL SHOULD OCCUR. ADDITIONAL CONVECTION MAY FORM
AROUND SUNRISE AND WILL BLOSSOM AS THE WEAK FRONT INTERACTS WITH
DAYTIME HEATING. THUS EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS TO
BE OCCURRING BY EARLY AFTERNOON ACROSS PORTIONS OF THE MIDSOUTH.
FOR THE REST OF THE WEEKEND...HAVE LEFT SMALL POPS OF 20-30S.
A STRONGER COLD FRONT WILL MOVE INTO THE AREA
MONDAY INTO MONDAY NIGHT. BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL OCCUR WITH THE FRONT.
COOLER AND DRIER AIR WILL FILTER INTO THE MIDSOUTH BEHIND THE
FRONT. HIGH PRESSURE WILL SETTLE OVER THE REGION FOR THE MIDDLE TO
END OF NEXT WEEK. HIGHS WILL BE IN THE MID TO UPPER 80S WITH LOWS
IN THE 60S.
KRM
&&
.AVIATION...06Z TAF CYCLE
THUNDERSTORMS ARE LINGERING THIS EVENING...AND CURRENTLY APPROACHING
MEM. WILL KEEP VCTS IN THE TAF THROUGH 07Z. RADAR TRENDS SEEM TO
FINALLY BE WEAKENING...BUT STORMS THIS EVENING HAVE BEEN VERY
PERSISTENT.
THE UNSETTLED WEATHER PATTERN CONTINUES WITH NO DISTINCT FEATURE
TO BASE THE FORECAST ON...SO WILL LEAN TOWARDS CONSISTENCY FOR THE
UPCOMING TAF CYCLE. EXPECT THUNDERSTORMS TO DEVELOP EARLY TOMORROW
AND REMAIN ACTIVE THROUGH THE DAY. ADDITIONAL STORMS CANNOT BE
RULED OUT TONIGHT...BUT AT THIS POINT FEEL SAFE LEAVING ANY
MENTION OUT OF THE FORECAST FOR NOW. WINDS WILL BE LIGHT
TONIGHT...INCREASING SLIGHTLY TOMORROW...FROM THE SOUTHWEST. PATCHY
FOG IS POSSIBLE...MAINLY AT MKL AND TUP. LOCALLY VFR CONDITIONS DUE
TO HEAVY RAIN IS POSSIBLE ALONG WITH BRIEF GUSTY WIND. COVERAGE AND
STRENGTH OF STORMS SHOULD DIMINISH AFTER SUNSET.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1238 PM CDT SAT AUG 9 2014
.AVIATION...
/18Z TAFS/
VFR conditions will again prevail through tomorrow. More scattered
mid level clouds will be possible through early evening. A few may
produce some showers, but theses showers will be scattered and
brief, so have not mentioned in the TAFS. Winds may be
occasionally gusty this afternoon.
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT SAT AUG 9 2014/
AVIATION...
/12Z TAFS/
VFR conditions should prevail across West Central Texas terminals
through tonight. A few isolated showers and storms are possible,
mainly near KABI-Abilene, but given the sparse nature and the
small odds of actually passing over a site, will not mention at
this time.
PREV DISCUSSION... /ISSUED 400 AM CDT SAT AUG 9 2014/
SHORT TERM...
(Today and tonight)
Scattered showers and thunderstorms developed Friday evening and
continue into the early morning hours across portions of the Big
Country and the Concho Valley. Several outflow boundaries have
rippled to the south. These boundaries have at least provided for
slightly cooler conditions behind the boundaries, with temperatures
in the mid 70s instead of the lower 80s ahead of them.
For today, similar to our discussion from yesterday morning, latest
TTU WRF and HRRR show at least isolated convection this afternoon
across portions of the Big Country, mainly north of I-20 where the
outflow boundaries will have an effect. Have again added slight
chance pops up there for today.
Highs on Friday afternoon were 1 or 2 degrees cooler than on
Thursday, and with the models suggesting the upper level ridge will
continue to gradually weaken across the area, temperatures should
cool another degree or two. Upper 90s to around 100 expected.
LONG TERM...
Upper level ridging will continue into the later part of next
week. However, not all showers and thunderstorms will be
suppressed with the upper ridging. A thunderstorm complex in the
Panhandle Sunday may move into the Big Country late Sunday night,
A weak cold front will also move into the Big Country Monday
afternoon, and push south as far as the I-10 corridor Monday
night. This front will also provide an additional low level focus
for thunderstorm development. Kept a slight chance of
thunderstorms going Tuesday and Tuesday night, mainly in the
Concho Valley and areas southward, as the front washes out.
Temperatures Sunday will be near or slightly above 100 degrees.
Highs the rest of next week should be 2 to 4 degrees less hot, with
isolated storms and increased cloud cover.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 100 76 100 76 96 / 20 10 5 20 20
San Angelo 100 74 100 74 98 / 5 10 5 5 20
Junction 100 75 99 75 98 / 5 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Reimer
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
623 AM CDT SAT AUG 9 2014
.AVIATION...
/12Z TAFS/
VFR conditions should prevail across West Central Texas terminals
through tonight. A few isolated showers and storms are possible,
mainly near KABI-Abilene, but given the sparse nature and the
small odds of actually passing over a site, will not mention at
this time.
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT SAT AUG 9 2014/
SHORT TERM...
(Today and tonight)
Scattered showers and thunderstorms developed Friday evening and
continue into the early morning hours across portions of the Big
Country and the Concho Valley. Several outflow boundaries have
rippled to the south. These boundaries have at least provided for
slightly cooler conditions behind the boundaries, with temperatures
in the mid 70s instead of the lower 80s ahead of them.
For today, similar to our discussion from yesterday morning, latest
TTU WRF and HRRR show at least isolated convection this afternoon
across portions of the Big Country, mainly north of I-20 where the
outflow boundaries will have an effect. Have again added slight
chance pops up there for today.
Highs on Friday afternoon were 1 or 2 degrees cooler than on
Thursday, and with the models suggesting the upper level ridge will
continue to gradually weaken across the area, temperatures should
cool another degree or two. Upper 90s to around 100 expected.
LONG TERM...
Upper level ridging will continue into the later part of next
week. However, not all showers and thunderstorms will be
suppressed with the upper ridging. A thunderstorm complex in the
Panhandle Sunday may move into the Big Country late Sunday night,
A weak cold front will also move into the Big Country Monday
afternoon, and push south as far as the I-10 corridor Monday
night. This front will also provide an additional low level focus
for thunderstorm development. Kept a slight chance of
thunderstorms going Tuesday and Tuesday night, mainly in the
Concho Valley and areas southward, as the front washes out.
Temperatures Sunday will be near or slightly above 100 degrees.
Highs the rest of next week should be 2 to 4 degrees less hot, with
isolated storms and increased cloud cover.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 100 76 100 76 96 / 20 10 5 20 20
San Angelo 100 74 100 74 98 / 5 10 5 5 20
Junction 100 75 99 75 98 / 5 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
400 AM CDT SAT AUG 9 2014
.SHORT TERM...
(Today and tonight)
Scattered showers and thunderstorms developed Friday evening and
continue into the early morning hours across portions of the Big
Country and the Concho Valley. Several outflow boundaries have
rippled to the south. These boundaries have at least provided for
slightly cooler conditions behind the boundaries, with temperatures
in the mid 70s instead of the lower 80s ahead of them.
For today, similar to our discussion from yesterday morning, latest
TTU WRF and HRRR show at least isolated convection this afternoon
across portions of the Big Country, mainly north of I-20 where the
outflow boundaries will have an effect. Have again added slight
chance pops up there for today.
Highs on Friday afternoon were 1 or 2 degrees cooler than on
Thursday, and with the models suggesting the upper level ridge will
continue to gradually weaken across the area, temperatures should
cool another degree or two. Upper 90s to around 100 expected.
.LONG TERM...
Upper level ridging will continue into the later part of next
week. However, not all showers and thunderstorms will be
suppressed with the upper ridging. A thunderstorm complex in the
Panhandle Sunday may move into the Big Country late Sunday night,
A weak cold front will also move into the Big Country Monday
afternoon, and push south as far as the I-10 corridor Monday
night. This front will also provide an additional low level focus
for thunderstorm development. Kept a slight chance of
thunderstorms going Tuesday and Tuesday night, mainly in the
Concho Valley and areas southward, as the front washes out.
Temperatures Sunday will be near or slightly above 100 degrees.
Highs the rest of next week should be 2 to 4 degrees less hot, with
isolated storms and increased cloud cover.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 100 76 100 76 96 / 20 10 5 20 20
San Angelo 100 74 100 74 98 / 5 10 5 5 20
Junction 100 75 99 75 98 / 5 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/04
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
705 PM CDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND OVER
THE EASTERN GREAT LAKES...WHILE TROUGHING WAS DROPPING SOUTH THROUGH
SOUTH CENTRAL CANADA. TWO OTHER SHORTWAVE TROUGHS WERE EVIDENT OVER
NORTHERN MN AND SOUTHERN IOWA. BOTH OF THESE SHORTWAVE TROUGHS WERE
PRODUCING SHOWERS AND SOME THUNDERSTORMS...BUT SO FAR THEY HAVE
STAYED WEST OF THE FORECAST AREA. THIS IS DUE TO HIGH PRESSURE
REMAINING IN PLACE OVER THE GREAT LAKES...PROVIDING A FLOW OF DRY
AIR INTO THE REGION. GOES PRECIPITABLE WATER IMAGERY DEPICTED THE
DIFFERENCE IN MOISTURE WELL...RANGING FROM 1-1.25 INCHES OVER THE
FORECAST AREA TO 1.5-1.75 INCHES FROM NORTH CENTRAL MN INTO WESTERN
IOWA AND MISSOURI. THE DRIER AIRMASS OVER THE FORECAST AREA HAS LED
TO A MOSTLY SUNNY DAY...AMD WITH 850MB TEMPS OF 12-14C ON 12Z
RAOBS...TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S/LOW 80S. IN THE
SEA LEVEL PRESSURE FIELD...MAIN ITEM TO NOTE IS A COLD FRONT
TRACKING ACROSS WESTERN MN AHEAD OF THE SOUTH CENTRAL CANADA UPPER
TROUGH. ANOTHER SIGNIFICANT DRY AIRMASS WAS COMING IN BEHIND IT WITH
PRECIPITABLE WATER VALUES OF 0.5-0.75 INCHES ACROSS NORTH DAKOTA.
OVER THE NEXT 24 HOURS...THE TROUGHING OVER SOUTH CENTRAL CANADA IS
PROGGED TO DROP THROUGH THE FORECAST AREA. AS THE TROUGHING
APPROACHES...THE STREAM OF HIGHER PRECIPITABLE WATER VALUES JUST OFF
TO OUR WEST WILL MOVE INTO THE FORECAST AREA...BRINGING THE
POTENTIAL FOR PRECIPITATION. HOWEVER...FORCING MECHANISMS FOR
PRECIPITATION ARE A BIT PROBLEMATIC. FOR TONIGHT...THAT SHORTWAVE
TROUGH OVER NORTHERN MN IS PROGGED TO PROGRESS TOWARDS LAKE
SUPERIOR...WHILE THE SHORTWAVE TROUGH OVER IOWA HEADS DOWN INTO
MISSOURI AND SOUTHERN ILLINOIS. THUS...THESE SHORTWAVES SPLIT AROUND
THE REGION. MODEL QPF PROGS REFLECT THIS WELL. PERHAPS SOME SHOWERS
TRAILING SOUTH OF THE NORTHERN MN SHORTWAVE...AIDED BY DAYTIME
HEATING...WILL MAKE IT INTO NORTHWEST SECTIONS OF THE FORECAST AREA.
THIS IS EVIDENT ON CURRENT RADAR IMAGERY. THUS...HAVE MAINTAINED
SOME LOW PRECIPITATION CHANCES.
HEADING INTO MONDAY...PRECIPITATION CHANCES LOOK A LITTLE
BETTER...PRIMARILY ACROSS WISCONSIN AS THE MAIN TROUGHING COMES
THROUGH AT PEAK HEATING. ITS INTERESTING TO NOTE THAT THE SURFACE
COLD FRONT SHOULD COME THROUGH TONIGHT...BUT THE MOISTURE REALLY
DOESNT GET SCOURED OUT UNTIL THE MAIN TROUGHING MOVES IN. WITH
GOOD MODEL AGREEMENT FOR SHOWERS AND STORMS TO FIRE ACROSS
WISCONSIN IN THE LATE MORNING AND AFTERNOON...HAVE KEPT
PRECIPITATION CHANCES UP IN THE 60-70 RANGE. ONE THING WE WILL
HAVE TO WATCH IS SOME OF THE 12Z HIRES MODELS...ARW/NMM/SPCWRF-
NMM...SUGGEST PRECIPITATION COULD INITIATE JUST EAST OF THE
FORECAST AREA AND STAY TO THE EAST. WEST OF THE MS RIVER...CLOUDS
THAT MOVE IN TONIGHT ARE LIKELY TO CLEAR AS THE LOWER PRECIPITABLE
WATER VALUES ADVECT IN.
NOT ANTICIPATING ANYTHING SEVERE WITH THE STORMS ON MONDAY. ALTHOUGH
EQUILIBRIUM LEVELS ARE UP NEAR 30000 FT...CAPE PROFILE OVERALL IS
QUITE SKINNY. 0-6KM SHEAR IS LESS THAN 25 KT AND WARM CLOUD DEPTHS
ARE AROUND 3500 M. IF ANYTHING...WE WILL HAVE A COUPLE OF HEAVY RAIN
PRODUCERS.
INCREASING CLOUDS AND HIGHER PRECIPITABLE WATER TONIGHT SHOULD
RESULT IN A WARMER NIGHT TONIGHT. COOLEST SPOT LIKELY TO BE IN
CENTRAL WI WHERE CLOUDS/MOISTURE ARRIVE LAST. CLOUDS WILL BE A BIT
OF AN ISSUE ON MONDAY FROM WARMING...BUT ENOUGH SUN SHOULD FILTER
THROUGH PLUS CLEARING WEST OF MS RIVER LATER IN THE DAY TO ALLOW FOR
HIGHS IN THE 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
STRONG DRYING AND SUBSIDENCE ARE ON TRACK TO COME INTO THE FORECAST
AREA MONDAY EVENING...PUSHING ANY LINGERING PRECIPITATION QUICKLY
OFF TO THE EAST AND CAUSING SKIES TO CLEAR OUT. PRECIPITABLE WATER
VALUES FALLING TO 0.5-0.75 INCHES BY 12Z TUESDAY WOULD BE FAVORABLE
FOR A GOOD RADIATIONAL COOLING NIGHT...BUT A PERSISTENT NORTHWEST
BREEZE SHOULD HELP A BIT FROM ALLOWING TEMPERATURES TO COMPLETELY
TANK.
TUESDAY THROUGH WEDNESDAY FEATURES GRADUALLY RISING 500MB HEIGHTS AS
UPPER TROUGHING DEVELOPS OVER THE PACIFIC NORTHWEST...PUSHING THE
UPPER RIDGING THERE EASTWARD AND THE NEW TROUGHING OVER THE FORECAST
AREA EASTWARD. SUBSIDENCE FROM THESE RISING 500MB HEIGHTS SHOULD
HELP TO KEEP THE FORECAST AREA DRY. HOWEVER...LATE WEDNESDAY...BOTH
THE 10.12Z GFS AND NAM DEPICT SOME LIGHT QPF MOSTLY NORTH OF I-90.
10.12Z ECMWF HAS SOME ISOLATED LIGHT QPF...MOSTLY NORTH OF I-90.
10.12Z CANADIAN ALSO DEPICTS SOME LIGHT QPF BUT SOUTH OF I-90. THIS
QPF IS A RESULT OF A WARM ADVECTION PATTERN DEVELOPING...WITH
ISENTROPIC LIFT/800-700MB MOISTURE TRANSPORT INITIATING PRECIPITABLE
BELOW THE 500MB SUBSIDENCE. CONCERNED THE GFS/NAM MAY BE OVERLY
WET...ESPECIALLY THE GFS...BUT WITH THE SIGNAL THERE HAVE INCLUDED A
MENTION OF SPRINKLES ALONG/NORTH OF I-90. TEMPERATURES TUESDAY
SHOULD BOUNCE WELL INTO THE 70S...FOLLOWED BY GOOD RADIATIONAL
COOLING AT NIGHT AS A SURFACE RIDGE SETTLES IN. COULD SEE SOME
VALLEY/RADIATIONAL FOG EARLY WEDNESDAY MORNING AS WELL. SLIGHTLY
WARMER 850MB TEMPS ON WEDNESDAY COMBINED WITH MORNING SUN SHOULD
HELP GIVE A COUPLE DEGREE BOOST TO HIGHS COMPARED TO TUESDAY.
IN THE EXTENDED RANGE...GOOD MODEL AGREEMENT EXISTS OF THE PACIFIC
NORTHWEST TROUGH LIFTING OUT AND TRACKING EAST...ALLOWING THE UPPER
RIDGE DOWNSTREAM EVENTUALLY TO MOVE OVER THE FORECAST AREA FOR THE
WEEKEND. THIS 500MB FLOW PATTERN SUGGESTS PERSISTENT WARM ADVECTION.
09.12Z/10.00Z ECMWF AND 10.12Z GFS IN FACT SUGGEST A BRIEF SURGE OF
HEAT TO COME INTO THE AREA ON SUNDAY. HOWEVER...THE NEW 10.12Z HAS
COMPLETELY WENT AWAY FROM THIS...DUE TO A SHORTWAVE TROUGH DIGGING
SOUTH THROUGH THE PLAINS WHICH BLOCKS THE HEAT FROM ARRIVING ON
SUNDAY. MOST DAYS WE SHOULD SEE HIGHS IN THE UPPER 70S TO PERHAPS AT
MOST MID 80S. ON THE PRECIPITATION SIDE OF THINGS...ITS POSSIBLE
THAT MID-LEVEL SHOWER/SPRINKLE STUFF FROM WEDNESDAY AFTERNOON
PERSISTS THROUGH FRIDAY. THE LOCATION LOOKS TO SHIFT TO MOSTLY WEST
OF THE MS RIVER AND MAY HAVE A FEW MORE SHOWERS WITH IT.
THEREFORE...DO HAVE SOME 20-30 PERCENT CHANCES. FRIDAY NIGHT THROUGH
THE WEEKEND IS NOW UP IN THE AIR AFTER THE 10.12Z ECMWF CAME IN.
PREVIOUSLY IT APPEARED A BETTER SHOT FOR SHOWERS AND STORMS WOULD
COME FRIDAY NIGHT AND SATURDAY AHEAD OF THE HEAT SURGE...AND AGAIN
LATE SUNDAY AS THE PACIFIC NORTHWEST TROUGH APPROACHED. HOWEVER...
THE NEW ECMWF HAS THE ENTIRE REGION UNDER HIGH PRESSURE AND DRY
CONDITIONS. HAVE SPLIT THE DIFFERENCE FOR NOW WHICH RESULTS IN 20-40
PERCENT CHANCES...MAYBE A 50 THERE ON SUNDAY. IF THE ECMWF IS RIGHT
WITH THIS SHORTWAVE DIVING THROUGH THE PLAINS...THE WEEKEND WILL
NEED TO BE DRIED OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 700 PM CDT SUN AUG 10 2014
FRONT MAKING SLOW PROGRESS TOWARD THE REGION...BUT NOT ANTICIPATED
TO HAVE ANY PRECIPIATION BY THAT TIME. MESOANALYSIS SHOWS NEXT TO
NO INSTABILITY AVAILABLE AS YOU MOVE EAST TOWARD KLSE...AND
SHOWERS HAVE BEEN DYING. MESOSCALE MODELS SHOW THIS DIMINISHING
TREND AS WELL. SO FOR NOW GOING WITH THAT SCENARIO AND NO SHOWERS
AT EITHER TAF SITE. WIND SHIFT WILL BE SLOW TO ARRIVE...AFTER
MIDNIGHT. MODELS ALL IN AGREEMENT THAT SOME LOW LEVEL MOISTURE
WILL SWEEP IN BEHIND THE FRONT...SO KEEPING A PERIOD OF MVFR
CEILINGS LOOKS PRUDENT. NORTHWEST WINDS AND GOOD MIXING EXPECTED
BY MID-DAY...WITH SOME GUSTS IN THE 20-25KT RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
616 PM CDT SUN AUG 10 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE STRETCHING FROM THE WESTERN GREAT LAKES TO NORTHEAST
NORTH AMERICA WHILE A COLD FRONT IS DROPPING SOUTHEAST OVER THE
NORTHERN GREAT PLAINS. A WEAK AREA OF LOW PRESSURE IS SPINNING OVER
CENTRAL MINNESOTA AHEAD OF THE FRONT...AND COMBINED WITH WEAK
SHORTWAVE ENERGY...IS PRODUCING SHOWERS FROM JUST WEST OF DULUTH TO
SOUTHWEST MINNESOTA. OTHER SPOTTIER SHOWERS ARE POPPING UP IN THE
MOISTURE RETURN OVER SOUTHERN AND CENTRAL LAKE MICHIGAN. MOST OF
THE MESO MODELS KEEP THESE LIGHT SPOTTY SHOWERS OR SPRINKLES
OFFSHORE OVER THE LAKE. BUT AS THE FRONT MOVES INTO THE REGION LATE
TONIGHT AND MONDAY...TIMING OF SHOWERS AND THUNDERSTORMS IS THE MAIN
FORECAST CONCERN.
TONIGHT...A SHORTWAVE TROUGH DROPPING SOUTHEAST OUT OF SOUTH-CENTRAL
CANADA WILL PUSH A COOL FRONT INTO NORTHWEST WISCONSIN LATE. AHEAD
OF THIS FRONT...LOW AND MID-LEVEL WINDS WILL SWING TO THE SOUTH AND
ADVECT MOISTURE FROM ILLINOIS AND INDIANA. A FEW SHOWERS FROM THIS
MOISTURE ARE PROJECTED TO REMAIN OVER THE LAKE. AMPLE CLOUD COVER
SHOULD ALSO ARRIVE WITH THE FRONT AS A WEAK AREA OF LOW PRESSURE
MOVES INTO CENTRAL WISCONSIN LATE. PROGGED SOUNDINGS INDICATE A
MID-LEVEL DRY WEDGE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN ERODING
LATE TONIGHT WHEN A MID-LEVEL THETAE AXIS MOVES INTO THAT PART OF
THE STATE. WILL RAMP UP PRECIP CHANCES AFTER 09Z WHEN THE COLUMN
BECOMES MORE SATURATED AND FORCING MARGINALLY INCREASES.
OTHERWISE...SLOWED DOWN THE CHANCE OF PRECIP THIS EVENING DUE TO THE
PRESENCE OF DRY AIR. LOW TEMPS SHOULD BE SEVERAL DEGREES WARMER DUE
TO THE INCREASING CLOUD COVER...AND WENT WITH TEMPS RANGING FROM
THE UPPER 50S NORTH OT LOWER 60S SOUTH.
MONDAY...THE SHORTWAVE AND COLD FRONT WILL GRADUALLY MOVE ACROSS
WISCONSIN. WITH DAYTIME HEATING...THE SREF INCREASES PRECIP CHANCES
DRAMATICALLY IN THE 15Z-18Z PERIOD OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...AND THEN SPREAD THE HIGHER PRECIP CHANCES INTO NORTHEAST
WISCONSIN AFTER MIDDAY. THIS LOOKS REASONABLE. TOUGH TO GET AN
ESTIMATE ON POTENTIAL INSTABILITY SINCE PROGGED SOUNDINGS LOOK
CONVECTIVELY MODIFIED...BUT A ROUGH ESTIMATE IS BETWEEN 500-1000
J/KG OF ML CAPE. BUT 0-6KM BULK SHEARS ARE ONLY AROUND 25 KTS AND
THINK FORCING IS TOO WEAK TO GENERATE MUCH OF A SEVERE THREAT. A
FEW STORMS COULD PRODUCE GUSTY WINDS TO 40-50 MPH AND SMALL HAIL.
MOSTLY CLOUDY AND MORE HUMID WITH HIGHS NEAR 70 NORTH TO AROUND 80
SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
RATHER STABLE MEAN LONGWAVE PATTERN FOR MOST OF THE EXTENDED WITH
NOTABLE TROUGHS SITUATED ON BOTH COASTS AND RIDGE OVER THE
INTER-MOUNTAIN WEST EXTENDING INTO CANADA. THE WESTERN GREAT LAKES
WILL REMAIN UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE BENEATH
NORTHWESTERLY FLOW ALOFT. PATTERN OFFERS LITTLE OPPORTUNITY FOR
SUBSTANTIAL RAINFALL FOR MOST OF THE WORK WEEK. SEASONABLY WARM
TEMPERATURES WITH COMFORTABLE DAYTIME HUMIDITIES...AND COOL NIGHTS
WILL BE THE RULE.
EARLY IN THE EXTENDED...DEEPENING UPPER TROUGH OVER THE GREAT
LAKES REGION MONDAY NIGHT WILL CONTINUE TO SWING EAST DURING THE
DAY ON TUESDAY. IN GENERAL...THE MODELS IN FAIRLY GOOD AGREEMENT
ON OVERALL TIMING OF BACK EDGE OF BROKEN BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS MONDAY EVENING. USING A BLENDED MODEL QPF
SUGGESTS THAT PRECIPITATION SHOULD BE EAST OF THE FORECAST AREA BY
06Z TUESDAY.
IN THE WAKE OF THE DEPARTING SURFACE LOW SITUATED NEAR LAKE HURON
TUESDAY MORNING...EXPECT FAIRLY DECENT NORTHERLY BOUNDARY LAYER
FLOW TO PERSIST AT LEAST FOR THE FIRST HALF OF THE DAY OVER THE
FORECAST AREA. GRADIENT SHOULD RELAX DURING THE AFTERNOON WITH
DIMINISHING WIND AND CLEARING SKIES. WITH THE CLOUDY START...COLD
ADVECTION...AND CORE OF COOLEST 850 TEMPS IN THE 8 TO 10 DEGREE
CELSIUS RANGE OVER THE AREA...DAYTIME HIGHS WILL BE THE COOLEST OF
THE WEEK...MAINLY IN THE LOW TO MID 70S.
DAYTIME HIGHS SHOULD MODERATE QUICKLY WEDNESDAY WITH READINGS
AROUND NORMAL FOR MIDDLE OF AUGUST. WEAK COLD FRONT DROPPING SOUTH
DURING THE DAY ON WEDNESDAY MAY BRING A FEW MORE CLOUDS AND
PERHAPS A SPRINKLE SOMETIME DURING THE DAY. DO NOT EXPECT MUCH
MORE THAN THAT GIVEN PALTRY MOISTURE AND FORCING.
HIGH PRESSURE REMAINS IN CONTROL THURSDAY AND FRIDAY WITH NEAR
NORMAL TEMPERATURES.
LATEST GUIDANCE WOULD ALSO SUGGEST SATURDAY WILL REMAIN DRY WITH
HINTS OF A CONFLUENT UPPER-LEVEL FLOW AND SURFACE RIDGE AXIS
PERSISTING OVER THE AREA.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 616 PM CDT SUN AUG 10 2014
VFR MID TO HIGH LEVEL CLOUDS AHEAD OF A WEAK COLD
FRONT WILL INCREASE THIS EVENING. SCATTERED SHOWERS WITH AREAS OF
MVFR CIGS WILL SPREAD OVER THE NORTHWEST HALF OF THE STATE LATE
TONIGHT...AND THEN OVER THE REST OF THE AREA ON MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
557 PM CDT SAT AUG 9 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 257 PM CDT SAT AUG 9 2014
FOCUS IN THE FORECAST WAS ON SHOWERS/STORMS SUNDAY NIGHT THROUGH
MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA.
LATEST WATER VAPOR IMAGERY COMBINED WITH RAP 500 MB HEIGHTS
SHOWED WEAK SHORTWAVE ACROSS THE EASTERN DAKOTAS DOWN INTO PARTS
OF IOWA THIS AFTERNOON. THIS FEATURE HAS SLOWLY BEEN WORKING EAST
TODAY...WEAKENING AS IT APPROACHES THE UPPER MISSISSIPPI RIVER
VALLEY. AT THE SURFACE...THE PERSISTENT GREAT LAKES HIGH PRESSURE
HAS KEPT THE LOW LEVELS PLENTY DRY WITH EASTERLY FLOW. MID
AFTERNOON READINGS WERE IN THE UPPER 70S TO LOWER 80S AND CLOUD
COVER VARIED FROM MOSTLY SUNNY ACROSS CENTRAL WISCONSIN...TO
MOSTLY CLOUDY NEAR THE I-35 CORRIDOR WITH MID/HIGH LEVEL CLOUDS.
SOME VERY LIGHT RADAR RETURNS ARE SHOWING UP FROM MSP TO DODGE
CENTER...LIFTING NORTH. COULD NOT RULE OUT A SPRINKLE IN DODGE
COUNTY THE REMAINDER OF THE AFTERNOON...OTHERWISE PLAN ON DRY
CONDITIONS.
ANOTHER PLEASANT EVENING AND OVERNIGHT FOR THE UPPER MS RIVER
VALLEY. THE AFOREMENTIONED UPPER LEVEL SHORTWAVE WILL FIZZLE OUT
OVER THE NEXT 12 HOURS...KEEPING THE FORECAST AREA DRY THROUGH
SUNDAY MORNING. OVERNIGHT LOWS WILL RANGE FROM MIDDLE 50S IN THE
COOLER CENTRAL WISCONSIN LOCATIONS...TO MIDDLE 60S ACROSS
SOUTHEAST MN / NORTHEAST IA UNDER MORE CLOUD COVER.
THE UPPER LEVEL WEATHER PATTERN WILL CHANGE TOMORROW AS THE
WESTERN RIDGE AMPLIFIES...AND SENDS A PIECE OF ENERGY DOWN TOWARD
THE AREA. AS THE SURFACE HIGH MOVES EAST...THIS WILL ALLOW THE
MOISTURE AXIS OF 65F DEWPOINTS TO SHIFT EAST AS WELL. MUCAPE
INCREASES TO AROUND 1000 J/KG BY AFTERNOON WEST OF THE MS
RIVER...AND IS MOSTLY UNCAPPED. EXPECTING POP UP AIRMASS
SHOWERS/STORMS TO DEVELOP ACROSS CENTRAL MINNESOTA DOWN INTO
NORTHWEST IOWA. WHILE THE BULK OF ANY SHOWER/STORM THREAT WILL BE
CONFINED ALONG/WEST OF I-35 DURING THE AFTERNOON...THIS WILL
SLOWLY WORK EAST TOWARD ROCHESTER AND CHARLES CITY AREAS BY
MID/LATE AFTERNOON. NO SEVERE THREAT SUNDAY AS 0-6 KM SHEAR IS ON
THE ORDER OF 10 KTS.
AS THE MAIN UPPER LEVEL SHORTWAVES ARRIVES MONDAY...THIS WILL
HELP DRIVE A COLD FRONT THROUGH THE AREA. OVERALL...DYNAMICS ARE
WEAK/MODERATE NOTED BY SOME 500-300 MB PV ADVECTION AND WEAK
850-700 MB FRONTOGENESIS. THE ONLY REAL POSITIVE IS THAT PWATS
WILL BE 1.5 TO 2.0 INCHES. THERE SHOULD BE PLENTY OF CLOUDS AROUND
MONDAY MORNING AND WITH CONVECTION AROUND...FORECAST HIGHS WILL
BE TRICKY. GUIDANCE IS TRENDING DOWN...AND HAVE FOLLOWED SUIT BY
LOWERING HIGHS SEVERAL DEGREES. THIS MAY NOT BE ENOUGH. THE
GREATER CLOUD COVER ALSO LIMITS HOW MUCH INSTABILITY WILL BE
AROUND...AND GIVEN THE SHEAR ENVIRONMENT IS NOT IMPRESSIVE AT
ALL...NOT EXPECTING ANY ORGANIZED SEVERE WEATHER. END RESULT WAS A
TIGHTENING OF THE POPS LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON.
ALSO INCREASED INTO THE 40-60 PERCENT RANGE...HIGHEST ACROSS
NORTH CENTRAL WISCONSIN WHERE THE GREATER FORCING/LIFT IS EXPECTED.
FRONT SLIDES THROUGH MONDAY EVENING...ENDING PRECIPITATION WEST
TO EAST. COOLER CANADIAN HIGH PRESSURE BEGINS TO BUILD IN FROM THE
WEST MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 257 PM CDT SAT AUG 9 2014
THE FRONT HALF OF THE EXTENDED LOOKS QUIET WITH AFOREMENTIONED HIGH
PRESSURE MOVING ACROSS THE UPPER MIDWEST. 850 MB TEMPERATURES OF
7-10 C WILL PUT HIGHS IN THE LOWER TO UPPER 70S TUESDAY AND
WEDNESDAY. WITH LOWER HUMIDITY AND MOSTLY TO PARTLY SUNNY
SKIES...IT SHOULD BE A COUPLE OF NICE DAYS.
09.12Z GUIDANCE SHOWS THE WESTERN RIDGE BREAKING DOWN HELPING TO
SEND A PIECE OF ENERGY ACROSS THE ROCKIES TOWARD THE UPPER MIDWEST
BY LATER IN THE UPCOMING WORK WEEK. STILL CONSIDERABLE TIMING
DIFFERENCES BETWEEN ALL OF THE MODELS...AS THE GFS REMAINS THE
FASTER SOLUTION. ADJUSTED MODEL CONSENSUS TO KEEP CHANCES WEST OF
THE MS RIVER THROUGH FRIDAY MORNING...THEN SPREAD SLIGHT CHANCES
ACROSS THE ENTIRE AREA ON FRIDAY. SEASONABLE TEMPERATURES LOOK TO
PREVAIL WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 557 PM CDT SAT AUG 9 2014
A SIMILAR PATTERN TO YESTERDAY REMAINS IN PLACE...WITH HIGH
PRESSURE STUCK OVER MICHIGAN AND DRY EASTERLY FLOW HELPING TO KEEP
CONDITIONS VFR. EXPECT THIS PATTERN TO STILL NOT CHANGE MUCH OVER
THE NEXT 24 HOURS...THUS THE FORECAST MAINTAINS MOSTLY VFR
CONDITIONS. THERE ARE TWO CONCERNS...THOUGH. THE FIRST IS
POTENTIAL FOR VALLEY FOG AND STRATUS AT LSE. A LIGHT EASTERLY
WIND AT THE GROUND IS FAVORABLE ALONG WITH PERHAPS JUST SCATTERED
CLOUDS AROUND. HOWEVER...10 TO 20 KT WINDS ARE MODELED JUST ABOVE
THE GROUND FOR MUCH OF THE NIGHT...COMBINED WITH THE LACK OF
RECENT RAINFALL YIELDS LOW CONFIDENCE OF THIS OCCURRING.
THEREFORE...HAVE MAINTAINED THE BCFG AND SCT LIFR DECK FOR NOW.
THE SECOND CONCERN IS LATE SUNDAY WHERE THERE IS A LOW CHANCE FOR
A SHOWER OR STORM TO MOVE INTO RST FROM THE WEST. GIVEN THE LOW
CHANCE AND THE EASTERLY DRY FLOW...HAVE KEPT PRECIPITATION OUT OF
THE TAF.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CDT SAT AUG 9 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 257 PM CDT SAT AUG 9 2014
FOCUS IN THE FORECAST WAS ON SHOWERS/STORMS SUNDAY NIGHT THROUGH
MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA.
LATEST WATER VAPOR IMAGERY COMBINED WITH RAP 500 MB HEIGHTS
SHOWED WEAK SHORTWAVE ACROSS THE EASTERN DAKOTAS DOWN INTO PARTS
OF IOWA THIS AFTERNOON. THIS FEATURE HAS SLOWLY BEEN WORKING EAST
TODAY...WEAKENING AS IT APPROACHES THE UPPER MISSISSIPPI RIVER
VALLEY. AT THE SURFACE...THE PERSISTENT GREAT LAKES HIGH PRESSURE
HAS KEPT THE LOW LEVELS PLENTY DRY WITH EASTERLY FLOW. MID
AFTERNOON READINGS WERE IN THE UPPER 70S TO LOWER 80S AND CLOUD
COVER VARIED FROM MOSTLY SUNNY ACROSS CENTRAL WISCONSIN...TO
MOSTLY CLOUDY NEAR THE I-35 CORRIDOR WITH MID/HIGH LEVEL CLOUDS.
SOME VERY LIGHT RADAR RETURNS ARE SHOWING UP FROM MSP TO DODGE
CENTER...LIFTING NORTH. COULD NOT RULE OUT A SPRINKLE IN DODGE
COUNTY THE REMAINDER OF THE AFTERNOON...OTHERWISE PLAN ON DRY
CONDITIONS.
ANOTHER PLEASANT EVENING AND OVERNIGHT FOR THE UPPER MS RIVER
VALLEY. THE AFOREMENTIONED UPPER LEVEL SHORTWAVE WILL FIZZLE OUT
OVER THE NEXT 12 HOURS...KEEPING THE FORECAST AREA DRY THROUGH
SUNDAY MORNING. OVERNIGHT LOWS WILL RANGE FROM MIDDLE 50S IN THE
COOLER CENTRAL WISCONSIN LOCATIONS...TO MIDDLE 60S ACROSS
SOUTHEAST MN / NORTHEAST IA UNDER MORE CLOUD COVER.
THE UPPER LEVEL WEATHER PATTERN WILL CHANGE TOMORROW AS THE
WESTERN RIDGE AMPLIFIES...AND SENDS A PIECE OF ENERGY DOWN TOWARD
THE AREA. AS THE SURFACE HIGH MOVES EAST...THIS WILL ALLOW THE
MOISTURE AXIS OF 65F DEWPOINTS TO SHIFT EAST AS WELL. MUCAPE
INCREASES TO AROUND 1000 J/KG BY AFTERNOON WEST OF THE MS
RIVER...AND IS MOSTLY UNCAPPED. EXPECTING POP UP AIRMASS
SHOWERS/STORMS TO DEVELOP ACROSS CENTRAL MINNESOTA DOWN INTO
NORTHWEST IOWA. WHILE THE BULK OF ANY SHOWER/STORM THREAT WILL BE
CONFINED ALONG/WEST OF I-35 DURING THE AFTERNOON...THIS WILL
SLOWLY WORK EAST TOWARD ROCHESTER AND CHARLES CITY AREAS BY
MID/LATE AFTERNOON. NO SEVERE THREAT SUNDAY AS 0-6 KM SHEAR IS ON
THE ORDER OF 10 KTS.
AS THE MAIN UPPER LEVEL SHORTWAVES ARRIVES MONDAY...THIS WILL
HELP DRIVE A COLD FRONT THROUGH THE AREA. OVERALL...DYNAMICS ARE
WEAK/MODERATE NOTED BY SOME 500-300 MB PV ADVECTION AND WEAK
850-700 MB FRONTOGENESIS. THE ONLY REAL POSITIVE IS THAT PWATS
WILL BE 1.5 TO 2.0 INCHES. THERE SHOULD BE PLENTY OF CLOUDS AROUND
MONDAY MORNING AND WITH CONVECTION AROUND...FORECAST HIGHS WILL
BE TRICKY. GUIDANCE IS TRENDING DOWN...AND HAVE FOLLOWED SUIT BY
LOWERING HIGHS SEVERAL DEGREES. THIS MAY NOT BE ENOUGH. THE
GREATER CLOUD COVER ALSO LIMITS HOW MUCH INSTABILITY WILL BE
AROUND...AND GIVEN THE SHEAR ENVIRONMENT IS NOT IMPRESSIVE AT
ALL...NOT EXPECTING ANY ORGANIZED SEVERE WEATHER. END RESULT WAS A
TIGHTENING OF THE POPS LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON.
ALSO INCREASED INTO THE 40-60 PERCENT RANGE...HIGHEST ACROSS
NORTH CENTRAL WISCONSIN WHERE THE GREATER FORCING/LIFT IS EXPECTED.
FRONT SLIDES THROUGH MONDAY EVENING...ENDING PRECIPITATION WEST
TO EAST. COOLER CANADIAN HIGH PRESSURE BEGINS TO BUILD IN FROM THE
WEST MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 257 PM CDT SAT AUG 9 2014
THE FRONT HALF OF THE EXTENDED LOOKS QUIET WITH AFOREMENTIONED HIGH
PRESSURE MOVING ACROSS THE UPPER MIDWEST. 850 MB TEMPERATURES OF
7-10 C WILL PUT HIGHS IN THE LOWER TO UPPER 70S TUESDAY AND
WEDNESDAY. WITH LOWER HUMIDITY AND MOSTLY TO PARTLY SUNNY
SKIES...IT SHOULD BE A COUPLE OF NICE DAYS.
09.12Z GUIDANCE SHOWS THE WESTERN RIDGE BREAKING DOWN HELPING TO
SEND A PIECE OF ENERGY ACROSS THE ROCKIES TOWARD THE UPPER MIDWEST
BY LATER IN THE UPCOMING WORK WEEK. STILL CONSIDERABLE TIMING
DIFFERENCES BETWEEN ALL OF THE MODELS...AS THE GFS REMAINS THE
FASTER SOLUTION. ADJUSTED MODEL CONSENSUS TO KEEP CHANCES WEST OF
THE MS RIVER THROUGH FRIDAY MORNING...THEN SPREAD SLIGHT CHANCES
ACROSS THE ENTIRE AREA ON FRIDAY. SEASONABLE TEMPERATURES LOOK TO
PREVAIL WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1228 PM CDT SAT AUG 9 2014
SIMILAR CONCERNS TO THE PAST FEW DAYS. SHORT WAVE TROUGH MOVING
SLOWLY EAST THROUGH SD AND TOWARD MN BUT HINDERED BY PRESENCE OF
REX BLOCK OVER WESTERN GREAT LAKES. AGAIN EXPECTING SOME DIURNAL
CUMULUS TODAY AND SUNDAY...BUT OTHERWISE DEALING PRIMARILY WITH
MID/HIGH CLOUD SPREADING EAST WHILE BEING ERODED BY DRY EASTERLY
FLOW OUT OF THE GREAT LAKES HIGH. WITH WEAK FLOW COULD STILL SEE
PATCHES OF VALLEY FOG. AGAIN...NOT TERRIBLY CONFIDENT IT WILL BE
WIDESPREAD...AND WE DID NOT SEE A GREAT DEAL LAST NIGHT. BUT DO
THINK IT IS POSSIBLE...SO DID MAINTAIN THE MENTION THAT WAS ADDED
DURING THE 12Z ISSUANCE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....MW
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 251 PM CDT SAT AUG 9 2014
LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
STRETCHING FROM NORTHEAST NORTH AMERICA TO THE WESTERN GREAT LAKES
EARLY THIS AFTERNOON. DIURNAL CU POPPED AWAY FROM THE GREAT LAKES
AROUND MIDDAY WHILE A WEAK SHORTWAVE OVER IOWA IS SPREADING CIRRUS
NORTHEAST ACROSS THE WESTERN HALF OF THE BADGER STATE. ADDITIONAL
SHORTWAVE ACTIVITY IS SPINNING OVER THE DAKOTAS. PRECIPITATION FROM
THESE SHORTWAVES ARE CONFINED TO THE DEEPER MOISTURE OVER IOWA AND
MINNESOTA SINCE EAST FLOW CONTINUES TO FUNNEL IN DRY MID-LEVEL AIR
INTO EASTERN WISCONSIN. CLOUDS AND TEMPS REMAIN THE MAIN FORECAST
CONCERNS IN THE SHORT TERM.
TONIGHT...THE WEAK SHORTWAVE OVER IOWA WILL CONTINUE TO LIFT TO THE
ENE ACROSS NORTHERN ILLINOIS AND SOUTHERN WISCONSIN. DRY EAST TO
SOUTHEAST FLOW IN THE LOW TO MID-LEVELS SHOULD KEEP THIS PART OF THE
ATMOSPHERE DRY SO THINKING WE SHOULD JUST SEE AN INFLUX OF HIGH
CLOUDS FROM THIS SHORTWAVE. BUT THIS WILL BE MORE CLOUD COVER
OVERHEAD THAN THE PAST FEW NIGHTS SO THINKING LOWS WILL BE A COUPLE
DEGREES WARMER. LOWS RANGING THROUGH THE 50S.
SUNDAY...A LITTLE DEEPER SHORTWAVE ENERGY WILL BE MOVING INTO
WISCONSIN FROM THE WEST BUT WILL BE WEAKENING AS IT DOES SO. THE
DEEPEST MOISTURE WILL REMAIN WEST OF THE REGION...BUT BACKING
MID-LEVEL FLOW WILL ADVECT DEEPER MOISTURE INTO NORTHERN WISCONSIN
FROM THE SOUTH. AS A RESULT...SHOULD SEE A CLOUDIER AND MORE HUMID
DAY THAN TODAY. BUT THE CLOUDS WILL OFFSET WARMER LOW LEVEL TEMPS
SO SHOULD SEE TEMPS AROUND TODAYS READINGS.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 251 PM CDT SAT AUG 9 2014
PRIMARY FOCUS IN THE LONG TERM CONTINUES TO BE MONDAY AND MONDAY
NIGHT AS FRONTAL BOUNDARY DRIFTS SOUTHEAST ACROSS THE FORECAST
AREA...IN CONCERT WITH UPPER LEVEL JET ENERGY FORECAST TO DIVE
SOUTHEAST INTO THE WESTERN GREAT LAKES. THIS JET ENERGY EVENTUALLY
CARVES OUT AN UNSEASONABLY DEEP TROUGH OVER THE EASTERN CONUS BY
MIDWEEK...LEAVING THE WESTERN GREAT LAKES UNDER THE INFLUENCE OF A
NORTHWESTERLY FLOW REGIME FOR THE REMAINDER OF THE WORK WEEK.
CONSENSUS OF MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE DEEPENING
TROUGH OVER THE WESTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY AND
ASSOCIATED FRONTAL BOUNDARY WILL BEGIN TO IMPACT THE FORECAST AREA
MOST LIKELY AFTER 09Z MONDAY. ASSOCIATED BROKEN BAND OF SHOWERS
AND A FEW THUNDERSTORMS SHOULD BEGIN TO IMPACT WESTERN AND CENTRAL
WISCONSIN AFTER 09Z AND THEN EASTERN SECTION AFTER 12Z. MODELS
CONTINUE TO SUGGEST THAT SCATTERED ACTIVITY ASSOCIATED WITH THE
FRONTAL BOUNDARY SHOULD BECOME SOMEWHAT MORE WIDESPREAD AS LFQ OF
UPPER JET HELPS TO ORGANIZE AND FOCUS UPPER-LEVEL FORCING AND
SYNOPTIC SCALE LIFT OVER THE FORECAST AREA. RESULTING SURFACE LOW
PRESSURE SYSTEM SHOULD DEEPEN SOMEWHERE OVER INDIANA OR LOWER
MICHIGAN AND LIFT NORTHEAST TO LAKE HURON AREA BY 18Z TUESDAY.
STILL SOME MODEL DIFFERENCE ON THE TIMIMG AND LOCATION OF THIS
EVOLUTION. WILL CONTINUE TO PLACE A BIT MORE WEIGHT ON THE ECMWF
DEPICTION OF THIS EVOLUTION FOR THIS PORTION OF THE FORECAST WHICH
WOULD SUGGEST THE PERIOD FROM ABOUT 18Z MONDAY THROUGH ABOUT 06Z
TUESDAY TO BE THE MOST FAVORABLE WINDOW FOR BENEFICIAL RAINFALL
FOR NORTHEAST WISCONSIN...WHICH COULD REALLY USE SOME RAIN. AT THIS
TIME DOES NOT APPEAR STABILITY WILL BE FAVORABLE FOR WIDESPREAD
THUNDERSTORM ACTIVITY. BEST CHANCE FOR THUNDER AND PERHAPS SOME
HEAVIER DOWNPOURS WOULD BE ON MONDAY AFTERNOON.
SURFACE LOW AND ASSOCIATED PRECIPITATION SHOULD PULL AWAY FROM THE
FORECAST AREA SOMETIME TUESDAY MORNING...FOLLOWED BY INCREASING
NORTHERLY WINDS...CAA AND PROBABLY A FAIR AMOUNT OF RESIDUAL
CLOUD COVER. WOULD THINK TUESDAY WILL BE THE COOLEST DAY IN THE
EXTENDED WITH DAYTIME HIGHS GENERALLY IN THE UPPER 60S TO LOWER
70S. SOME MODERATION IN TEMPERATURES THEREAFTER AS SURFACE HIGH
PRESSURE BEGINS TO EDGE EASTWARD TOWARD WISCONSIN TUESDAY NIGHT
AND WEDNESDAY. CONSENSUS OF MODEL GUIDANCE CONTINUES TO SUGGEST A
WEAK COLD FRONT TO DROP SOUTHWARD ACROSS THE FORECAST AREA
SOMETIME ON WEDNESDAY...BUT DOES NOT APPEAR IT WILL GENERATE MUCH
IF ANY SHOWER ACTIVITY...THUS FORECAST WILL REMAIN DRY. THURSDAY
LOOKS TO BE A SEASONABLY WARM DAY UNDER HIGH PRESSURE WITH HIGHS
BACK NEAR SEASONAL NORMALS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1154 AM CDT SAT AUG 9 2014
OTHER THAN SOME PATCHY MORNING GROUND FOG OVER N-C
WISCONSIN...VFR CONDITIONS TO PREVAIL TODAY THROUGH SUNDAY WITH
LIGHT SURFACE WINDS. UNLIKE THE PAST FEW DAYS...WILL HAVE MORE MID
AND HIGH CLOUDS ARRIVING LATE TONIGHT INTO SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 PM CDT FRI AUG 8 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM CDT FRI AUG 8 2014
LATEST WATER VAPOR IMAGERY COMBINED WITH RAP 500 MB HEIGHTS
SHOWED WEAK ZONAL FLOW ACROSS CENTRAL PLAINS INTO THE UPPER
MIDWEST. A COUPLE OF WEAK SHORTWAVE TROUGHS WERE TRAVERSING
THROUGH IOWA AND THE DAKOTAS. MEANWHILE...SURFACE HIGH PRESSURE
CONTINUED TO SIT OVER THE GREAT LAKES REGION KEEPING RELATIVELY
DRIER AIR MASS ACROSS WISCONSIN.
A PLEASANT FRIDAY NIGHT SETTING UP WITH EVENING TEMPERATURES IN
THE 70S...REACHING THE 60S OVERNIGHT. INCLUDED PATCHY FOG
OVERNIGHT ONCE AGAIN FOR THE RIVER VALLEYS AND COOLER SPOTS OF
CENTRAL WISCONSIN. SURFACE WINDS DO DROP OFF TO LIGHT/VARIABLE AND
IT SHOULD BE A MOSTLY CLEAR NIGHT. IT WILL DEPEND LARGELY ON HOW
MUCH DEWPOINT RECOVERY TAKES PLACE...AND IF THE WINDS JUST OFF THE
SURFACE STAY DOWN.
FOR SATURDAY...PLAN ON MORE MID/HIGH LEVEL CLOUDINESS ESPECIALLY
WEST OF THE MS RIVER AS WEAK SHORTWAVES MOVE ACROSS THE DAKOTAS
INTO WESTERN IOWA. AT THE SURFACE...THE GREATER MOISTURE AXIS WILL
CONTINUE TO LIE WEST OF THE I-35 CORRIDOR IN MINN/IOWA SO NOT
EXPECTING ANY RAIN SHOWERS. THIS IS LARGELY DUE TO THE INFLUENCE
OF THE GREAT LAKES HIGH PRESSURE KEEPING A STEADY FLOW OF DRIER
AIR IN PLACE ACROSS WISCONSIN. DEWPOINTS DURING THE AFTERNOON
SHOULD BOTTOM OUT IN THE MIDDLE 50S...KEEPING HUMIDITY LEVELS
COMFORTABLE. HIGHS WILL VARY FROM LOW/MID 80S ACROSS CENTRAL
WISCONSIN WHERE MORE SUN/MIXING IS EXPECTED...TO MID/UPPER 70S IN
THE WEST UNDER MORE CLOUDS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 254 PM CDT FRI AUG 8 2014
FOCUS IN THE LONG TERM IS ON SHOWER/STORM CHANCES LATE IN THE
WEEKEND THROUGH MONDAY NIGHT ASSOCIATED WITH A COLD FRONT.
THE MOIST AIRMASS THAT HAS REMAINED TO THE WEST THE PAST FEW DAYS
WILL SLOWLY ADVANCE EASTWARD...SUCH THAT BY SUNDAY AFTERNOON
DEWPOINTS LOOK TO BE BACK IN THE LOWER TO MIDDLE 60S. PRECIPITABLE
WATER OFF THE 08.12Z MODEL GUIDANCE IS FORECAST TO BE AROUND 1.5
INCHES...ESPECIALLY WEST OF THE MS RIVER. DESPITE LITTLE IN THE
WAY OF ORGANIZED FORCING MECHANISMS...WITH MUCAPE OF 500 J/KG AND
PWATS AROUND 1.5 INCHES IN A WEAK CAP ENVIRONMENT...POP UP AIRMASS
SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE. THE GREATER
CHANCES LOOK TO BE WEST OF THE FORECAST AREA...BUT HAVE INCLUDED
20-30 PERCENT CHANCES WEST OF A ROCHESTER TO CHARLES CITY LINE FOR
SUNDAY.
08.12Z GUIDANCE CONTINUED THE PREVIOUS CYCLES AGREEMENT OF A
FRONTAL PASSAGE ON MONDAY. THE UPPER LEVEL SHORTWAVE DEEPENS AS IT
APPROACHES THE UPPER MIDWEST...GENERATING A MODEST AMOUNT OF
500-300 MB PV ADVECTION. MOISTURE TRANSPORT LEAVES A LOT TO BE
DESIRED BUT WITH DEWPOINTS PEGGED TO BE IN THE MIDDLE
60S...MUCAPES UP TO 1000 J/KG...AND AN UNCAPPED
ENVIRONMENT...EXPECTING A ROUND OF SHOWERS/STORMS TO DEVELOP
DURING THE DAY. SHEAR PROFILES ARE VERY LACKING...UNIDIRECTIONAL
AND LESS THAN 15 KTS SO AT THIS TIME NOT EXPECTING ANY ORGANIZED
SEVERE WEATHER. WITH RUN-TO-RUN CONSISTENCY TRENDING
HIGHER...INCREASED POPS TO THE 40-50 PERCENT RANGE.
FRONTAL PASSAGE LOOKS PROGRESSIVE ENOUGH TO KEEP FORECAST DRY
TUESDAY THROUGH THURSDAY AND WITH CANADIAN HIGH PRESSURE BUILDING
IN FROM THE WEST...SEASONABLE TO SLIGHTLY BELOW NORMAL
TEMPERATURES WILL BE THE RULE.
DIFFERENCES CREEP UP THURSDAY NIGHT AND FRIDAY...WITH THE ECMWF
HOLDING THE AREA DRY WITH GREAT LAKES HIGH PRESSURE BUT THE GFS
ATTEMPTS TO BRING A MID LEVEL SHORTWAVE ACROSS THE PLAINS INTO THE
UPPER MS RIVER VALLEY. FOR NOW...GIVEN THE LACK OF CONSISTENCY AND
REAL PATTERN SIGNALS...SLIGHT CHANCES IN A MODEL CONSENSUS LOOK
GOOD AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1131 PM CDT FRI AUG 8 2014
EASTERLY FLOW FROM HIGH PRESSURE IN THE GREAT LAKES WILL CONTINUE
TO PROVIDE A FEED OF DRY AIR INTO THE TAF SITES...GENERALLY
MAINTAINING VFR CONDITIONS. THE ONE EXCEPTION TO THIS IS THE
VALLEY FOG POTENTIAL AT LSE THIS MORNING. THERE HAS BEEN VERY GOOD
RH RECOVERY THIS EVENING...ENOUGH THAT THE CONCERN FOR VALLEY FOG
HAS INCREASED. ON THE OTHER HAND...THERE REMAINS SCATTERED TO
BROKEN ALTOSTRATUS MOVING THROUGH...THE POTENTIAL REMAINS FOR
10-15 KT WINDS TO DEVELOP JUST ABOVE THE GROUND OVERNIGHT...AND
ITS BEEN AWHILE SINCE THE LAST RAIN. GIVEN THESE NEGATIVES...HAVE
KEPT THE BCFG BETWEEN 09-1415Z BUT DID INCLUDE A SCT LIFR DECK
GIVEN THE RH RECOVERY. WILL HAVE TO KEEP A MONITOR ON THE VALLEY
THROUGH THE MORNING HOURS FOR NEED OF VISIBILITY AND/OR CEILING
RESTRICTIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
400 PM MDT SAT AUG 9 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 303 PM MDT SAT AUG 9 2014
STORMS ARE A LITTLE LESS WIDESPREAD THIS AFTN WITH THE EXCEPTION OF
THE NORTHERN HALF OF THE PANHANDLE. WEAK SHORTWAVE IS CURRENTLY
MOVING OVER THE CWA WITH THE SFC TROUGH JUST TO THE EAST OF THE
CWA. AS A RESULT...SFC WINDS ARE NORTH-TO-NORTHWEST OVER MUCH OF
THE CWA WITH A WEAK FRONT PASSING THROUGH. THESE WINDS HAVE BEEN
BREEZY AT TIMES WITH GUSTS TO 25-30 KTS. BEST SHOT AT STRONGER
STORMS THRU THE AFTN WILL BE TO THE NORTH OF THE NORTH PLATTE VALLEY
ACROSS THE NEBRASKA PANHANDLE. WHILE THE SOUTHERN PANHANDLE IS
DRIER (DEWPOINTS IN THE MID 40S)...LOCATIONS OVER THE NORTHERN
PANHANDLE ARE SEEING DEWPOINTS IN THE 55-50F RANGE. THE SPC
MESOANALYSIS SHOWS MLCAPES OF 1250-1500 OVER DAWES AND SIOUX
COUNTIES...HOWEVER THE MAIN LIMITING FACTOR FOR A GREATER SVR THREAT
WILL BE THE LACK OF SHEAR (BULK SHEAR IS ONLY 20-25 KTS). KEPT
SMALL HAIL IN THE FCST THROUGH THE AFTN FOR THE NORTHERN PANHANDLE
ESPECIALLY SINCE THE HRRR HAS BEEN CONSISTENTLY SHOWING STRONGER
STORMS OVER THIS AREA. STORMS COULD LINGER OVER THE PANHANDLE
THROUGH THE LATE EVENING AND THEN TAPER OFF THEREAFTER.
NORTHERLY WINDS WILL CONTINUE ACROSS THE PLAINS THROUGH THE NIGHT
WITH SFC PRESSURES RISING OVER THE CWA. WINDS WILL TURN EASTERLY BY
SUN AFTN WITH CONVERGENCE INCREASING OVER THE SOUTHERN LARAMIE
RANGE. THE MAIN MODEL TREND OVER THE PAST DAY IS TO SHOW LESS
INSTABILITY AND QPF ALONG THE SOUTHERN LARAMIE RANGE DURING THE
AFTN. APPEARS MORE AND MORE THAT NORTHERN COLORADO WILL SEE MUCH OF
THE STORM ACTIVITY...SO LOWERED POPS IN AREAS NEAR THE COLORADO
BORDER. TEMPS WILL BE ABOUT 5 DEGREES COOLER IN THE POST FRONTAL
AIRMASS. SUBTROPICAL HIGH CENTER SHIFTS WESTWARD TOWARD THE FOUR
CORNERS REGION BY MON WITH HEIGHTS RISING AND MONSOONAL MOISTURE
BEING SHUNTED WELL TO THE SOUTH AND WEST OF WY. WILL BE HARD
PRESSED TO GET MUCH MORE THAN ISOLATED STORM DEVELOPMENT IN THIS
TYPE OF PATTERN...WITH THE BEST CHANCES OVER THE HIGHER TERRAIN OF
SOUTHEAST WY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 330 PM MDT SAT AUG 9 2014
12Z MEDIUM RANGE MODEL GUIDANCE PROGS A STOUT UPPER RIDGE ALONG
THE FRONT RANGE TUESDAY TRANSLATING EAST THROUGH THE HIGH PLAINS
WEDNESDAY...AND EASTERN GREAT PLAINS THURSDAY. MEANWHILE...A UPPER
TROUGH ENTERS THE GREAT BASIN EARLY IN THE PERIOD...THEN LIFTS
NORTHEAST ACROSS THE NORTHERN ROCKY MOUNTAINS BY WEEK/S END. THE
ECMWF DEVELOPS A DOUBLE-BARREL LOW WHEREAS THE GFS MAINTAINS A
POSITIVE OPEN TROUGH WITH ITS MERIDIONAL AXIS ALONG THE FRONT RANGE.
A SURFACE RIDGE WILL BE SITUATED OVER THE NORTHERN/CENTRAL GREAT
PLAINS TUESDAY WITH A STATIONARY FRONT DRAPED OVER SOUTHEAST WY
AND EASTERN CO. WITH THE UPPER RIDGE AXIS OVER THE FRONT RANGE...
MUCH OF THE SUBTROPICAL MOISTURE WILL BE CONFINED SOUTH AND WEST
OF THE CWA. ISOLATED DIURNAL CONVECTION WILL BE POSSIBLE ALONG
AND WEST OF THE LARAMIE RANGE. AS THE RIDGE DRIFTS EAST TOWARD
THE HIGH PLAINS WEDNESDAY...SOUTHWEST FLOW ALOFT WILL TRANSPORT
MORE SUBTROPICAL MOISTURE INTO THE REGION WITH MORE SCATTERED
CONVECTION. A SHORTWAVE LIFTING NORTHEAST ACROSS EASTERN WY/CO
WILL LIKELY KEEP CONVECTION GOING INTO THE OVERNIGHT HOURS.
CONVECTIVE COVERAGE WILL BE MORE ISOLATED AND DIURNAL IN NATURE
THURSDAY AS FORCING WILL BE EAST OF THE CWA AND SUBTROPICAL
MOISTURE NOT AS PREVALENT AS THE FLOW ALOFT BECOMES MORE WESTERLY.
THE GFS LOOKS OVERDONE WITH QPF GIVEN THE ABOVE SCENARIO AND
LEANED CLOSER TO THE ECMWF. ANOTHER SHORTWAVE TROUGH WILL IMPACT
THE CWA FRIDAY/FRIDAY NIGHT WITH SLIGHTLY BETTER COVERAGE OF
CONVECTION. SATURDAY WILL TREND DRIER IN THE WAKE OF THE WAVE
WITH WEST-NORTHWEST FLOW ALOFT. COULD SEE ISOLATED DIURNAL
CONVECTION OVER WESTERN NEBRASKA WITH MARGINAL INSTABILITY AND
MOISTURE.
TEMPERATURES WILL AVERAGE 5 TO 10 DEGREES WARMER THAN NORMAL FOR
TUESDAY AND WEDNESDAY...THEN GRADUALLY COOL CLOSER TO SEASONAL
NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1148 AM MDT SAT AUG 9 2014
EXPECT VFR OUTSIDE CONVECTIVE ACTIVITY. ISLD TO SCT TSTORM
DEVELOPMENT MAINLY ALONG/EAST OF LARAMIE RANGE BETWEEN 20Z AND 03Z
WILL PRODUCE OCNL MVFR VSBYS. NORTHWESTERLY WINDS WILL BE BREEZY
AT TIMES THIS AFTN...OCNLY VARIABLE/GUSTY INVOF TSTORM ACTIVITY.
PARTIAL CLEARING SKIES AFTER CONVECTION DISSIPATES LATER THIS
EVE. CANNOT RULE OUT POSSIBILITY OF LOW CIGS/VSBYS AFTER 10Z FOR
PORTIONS OF THE WESTERN NE PNHDL.
&&
.FIRE WEATHER...
ISSUED AT 303 PM MDT SAT AUG 9 2014
AFTERNOON SHOWERS AND THUNDERSTORMS WILL BECOME MORE ISOLATED ON
SUNDAY AND INTO EARLY NEXT WEEK AS MONSOONAL MOISTURE GETS PUSHED
SOUTH OF THE REGION. TEMPERATURES ON SUNDAY WILL BE SLIGHTLY BELOW
NORMAL AS A COLD FRONT PUSHES ACROSS THE REGION TONIGHT. A WARMUP
WILL BEGIN ON MONDAY AND CONTINUE INTO MIDWEEK. MINIMUM HUMIDITY
VALUES WILL DROP TO AROUND 20-25 PERCENT ACROSS AREAS TO THE WEST OF
THE LARAMIE RANGE ON MONDAY AND TUESDAY AFTERNOONS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...JAMSKI
AVIATION...JAMSKI
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
601 AM EDT MON AUG 11 2014
...ANOTHER ROUND OF HEAVY RAINS AND DANGEROUS FLASH FLOODING
POSSIBLE THROUGH THIS EVENING...
.SYNOPSIS...
A WEAKENING STATIONARY FRONT WILL CONTINUE TO PRODUCE UNSETTLED
WEATHER OVER THE AREA TODAY. A COLD FRONT WILL SHIFT INTO THE
REGION MID TO LATE WEEK...BRINGING DRIER WEATHER TO THE SOUTHEAST
STATES. REMNANTS OF THE LINGERING FRONT COULD LIFT BACK NORTH
THROUGH THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES FOR THE SUNRISE UPDATE. THE 11/09Z RAP PICKED UP
ON THE HEAVY SHOWER ACTIVITY THAT IS CURRENTLY ANCHORED TO HUNTING
ISLAND. EXPECT ADDITIONAL CONVECTION TO SPREAD INLAND TOWARDS THE
CHARLESTON METRO AREA OVER THE NEXT FEW HOURS. COULD SEE AN
ENHANCED FLASH FLOOD THREAT IN THE DOWNTOWN CHARLESTON AREA BY
MID-MORNING WITH HIGH TIDE.
TODAY...ANOTHER ROUND OF HEAVY RAIN AND FLASH FLOODING WILL AFFECT
THE REGION TODAY. THE SYNOPTIC PATTERN HAS CHANGED LITTLE OVER THE
PAST FEW DAYS WITH A STATIONARY FRONT LINGERING OVER THE AREA. AT
11/07Z...THE FRONT WAS POSITIONED ROUGHLY ALONG OR JUST NORTH OF
THE SAVANNAH RIVER AND LINKED UP WITH A WAVE OF LOW PRESSURE
CENTERED WELL SOUTHEAST OF BUOY 41004. MODELS SHOW THE BOUNDARY
REMAINING NEARLY STATIONARY OVER THE AREA TODAY AND WILL SERVE AS
PRIMARY FOCUS FOR CONVECTION TO REFIRE LATER THIS MORNING THIS
AFTERNOON AS WAVES OF SHORTWAVE ENERGY TRAVERSE THE REGION. THE
HIGH RESOLUTION MODELS ARE SIMILAR IN SHOWING NUMEROUS TO
WIDESPREAD SHOWER/TSTMS DEVELOPING THIS AFTERNOON...FIRST
INITIATING OVER THE CHARLESTON TRI-COUNTY AREA LATER THIS MORNING
THEN REDEVELOPING SLOWLY SOUTH THROUGH THE LATE AFTERNOON HOURS.
POPS WILL BE INCREASED TO 70-90 PERCENT FOR ALL AREAS TODAY WITH
HIGHS RANGING FROM THE UPPER 80S/NEAR 90 NORTH TO THE LOWER 90S
SOUTH. SEE THE HYDROLOGY SECTION BELOW FOR ADDITIONAL INFORMATION
ON THE RISK FOR FLASH FLOODING THROUGH TONIGHT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...SIMILAR TO THE PAST FEW NIGHTS...CONVECTION WILL SLOWLY
DIMINISH WITH TIME WITH THE LOSS OF INSOLATION. HOWEVER...WEAK-
MODERATE INSTABILITY WILL REMAIN WHICH WILL FEED AT LEAST
ISOLATED-SCATTERED SHOWERS/TSTMS FOR MUCH OF THE NIGHT. LOWS WILL
RANGE LOWER-MID 70S INLAND TO THE MID-UPPER 70S AT THE COAST.
TUESDAY...THE PATTERN ALOFT WILL BE STEADILY TRANSITIONING...AS
STRONG SHORTWAVE ENERGY DIVES INTO THE GREAT LAKES/OHIO VALLEY
REGIONS AND SENDS AN AMPLIFYING UPPER TROUGH AXIS TOWARD THE EAST
COAST. THE SURFACE PATTERN WILL BE RATHER MUDDLED...WITH A WEAK
WAVE OF LOW PRESSURE ALONG A DIFFUSE BOUNDARY LIFTING NORTH INTO
THE MID ATLANTIC STATES DOWNSTREAM OF THE UPPER TROUGH AXIS. A
RIBBON OF DEEP MOISTURE...WHERE PRECIPITABLE WATER VALUES ARE 2
TO 2.25 INCHES...WILL REMAIN STRETCHED ACROSS THE CAROLINA AND
SOUTHEAST COASTLINE DURING THE MAJORITY OF THE DAY. CONSIDERING
THAT SYNOPTIC SCALE FORCING WILL STILL BE IN THE AREA...EXPECT
SHOWER/THUNDERSTORM COVERAGE TO ONCE AGAIN BE ABOVE SEASONAL
NORMALS. HAVE INDICATED RATHER HIGH RAIN CHANCES IN THE 50 PERCENT
RANGE GENERALLY ALONG AND INLAND OF THE SEABREEZE DURING THE
AFTERNOON HOURS...BEFORE MOISTURE DIMINISHES FROM WEST TO EAST
BEHIND THE DEPARTING LOW SYSTEM OVERNIGHT. STORM MOTIONS WILL BE
NOTABLY FASTER THAN THE PREVIOUS DAY...SUGGESTING THAT HEAVY
RAINFALL POTENTIAL AND LOCALIZED FLOODING WILL BE CONFINED TO
STORMS STALLED ALONG BOUNDARY INTERACTIONS. MID LEVEL DRY AIR EARLY
IN THE DAY AND SLIGHTLY HIGHER WIND FIELDS COULD SUPPORT AN
ISOLATED THUNDERSTORM BECOMING SEVERE AND PRODUCING DAMAGING WIND
GUSTS. ORGANIZED SEVERE WEATHER IS OTHERWISE NOT ANTICIPATED.
TEMPERATURES WILL PEAK IN THE LOWER 90S INLAND UNDER MOSTLY CLOUDY
SKIES.
WEDNESDAY...NUMERICAL MODEL FORECASTS HAVE ACCELERATED THE
APPROACH OF A COLD FRONT DEFINING THE LEADING EDGE OF DRIER HIGH
PRESSURE TO THE WEST/NORTHWEST. LATEST SOLUTIONS SUGGEST THAT THE
FRONT COULD SHIFT INTO THE FORECAST AREA BY LATE DAY...SWEPT
SOUTHEAST BY SHORTWAVE ENERGY EMBEDDED WITHIN THE LIFTING UPPER
TROUGH AXIS. HAVE MAINTAINED SOLID SHOWER/THUNDERSTORM CHANCES
WITH THE SURFACE FRONTAL TROUGH OVER THE FORECAST AREA PROVIDING
ADDITIONAL FORCING. DRIER MODELS ARE HINTING THAT BEST RAIN
COVERAGE COULD BE LIMITED TO THE COASTAL AREAS AND SOUTH OF
INTERSTATE 16 IN SOUTHEAST GEORGIA...CLOSEST TO THE LINGERING BAND
OF DEEP MOISTURE. PRECIPITABLE WATER VALUES WILL BE ON A NOTABLE
DOWNWARD TREND...THUS FLOODING CONCERNS WILL BE LESS THAN SEEN FOR
THE PAST SEVERAL DAYS. HAVE INDICATED THUNDERSTORM POTENTIAL
DIMINISHING FROM NORTHWEST TO SOUTHEAST DURING THE EVENING AND
NIGHTTIME HOURS. HIGH TEMPERATURES WILL REACH THE LOWER 90S UNDER
PARTLY CLOUDY SKIES NORTH TO MOSTLY CLOUDY SKIES SOUTH.
THURSDAY...THE COLD FRONT APPEARS STALLED ALONG THE SOUTHERN
PERIPHERY OF THE FORECAST AREA INTO THE LATE WEEK TIME
FRAME...WITH DEEP MOISTURE CONFINED ALONG AND SOUTH OF INTERSTATE
16 IN SOUTHEAST GEORGIA. A BROAD UPPER TROUGH PATTERN WILL REMAIN
ACROSS THE ENTIRE EASTERN UNITED STATES. HAVE HIGHLIGHTED FAR
SOUTHEAST GEORGIA AND THE SEABREEZE CORRIDOR FOR RAIN CHANCES
AROUND 20 TO 30 PERCENT...WHILE INDICATED ONLY ISOLATED
DEVELOPMENT ELSEWHERE. EXPECT HIGH TEMPERATURES TO BE A DEGREE OR
TWO COOLER THAN EARLIER IN THE WEEK...RANGING FROM 89 TO 92
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
DESPITE A PROMINENT AND PERSISTENT UPPER TROUGH ACROSS THE ENTIRE
EASTERN UNITED STATES FOR MUCH OF THE EXTENDED PERIOD...CONVECTIVE
COVERAGE SHOULD RETURN TO MORE SEASONAL NORMALS THROUGH AT LEAST
SUNDAY. HAVE INDICATED SLIGHT CHANCE TO LOW CHANCE POPS EACH
AFTERNOON...FORCED MAINLY BY TYPICAL SEABREEZE CONVERGENCE AND
DIURNAL INSTABILITY. MEDIUM RANGE MODEL SOLUTIONS THEN SUGGEST A
WEST TO EAST ORIENTED BOUNDARY...PERHAPS REMNANTS OF THE LATE WEEK
COLD FRONT...WILL LIFT NORTH AND BRING UNSETTLED WEATHER BACK TO
THE SOUTHEAST STATES FOR EARLY NEXT WEEK. HIGH TEMPERATURES WILL
VARY LITTLE THROUGH THE PERIOD...GENERALLY REACHING THE LOWER 90S
AWAY FROM THE LOCALLY COOLER COASTLINE EACH DAY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
SO FAR SUB-VFR CONDITIONS HAVE REMAINED WEST OF KCHS. WATCHING
TRENDS FOR A PSBL INCLUSION OF MVFR VSBYS/CIGS JUST BEFORE 12Z TAF
ISSUANCE. AT KSAV...LIFR CIGS HAVE RECENTLY DVLPD. THESE SHOULD
LINGER THROUGH SUNRISE BEFORE LIFTING.
ANOTHER VERY ACTIVE DAY IS EXPECTED ACROSS THE AREA WITH NUMEROUS
TO WIDESPREAD SHOWERS AND TSTMS. IMPACTS PROBABILITIES AT THE
TERMINALS LOOK HIGH AND PREVAILING MVFR TSRA CONDITIONS WILL BE
FORECASTED. LIMITED VSBYS/CIGS TO MVFR FOR NOW...ALTHOUGH TRANSIENT
PERIODS OF IFR/LIFR WILL BE POSSIBLE DURING PERIODS OF THE
HEAVIEST CONVECTIVE RAINFALL. WILL HIGHLIGHT TSTMS FROM 17-22Z AT
KCHS AND 20-02Z AT KSAV. AMENDMENTS WILL MOST CERTAINLY BE ISSUED
THROUGHOUT THE DAY AS TRENDS/TIMING BECOME MORE APPARENT.
EXTENDED AVIATION OUTLOOK...SCATTERED AND MAINLY DIURNAL SHRA/TSRA
WITH BRIEF PERIODS OF FLIGHT RESTRICTIONS ARE EXPECTED FOR TUESDAY
THROUGH THURSDAY.
&&
.MARINE...
TODAY AND TONIGHT...VARIABLE WIND FIELDS WILL REMAIN IN PLACE
THROUGH TONIGHT AS A WEAK STATIONARY WILL CONTINUE TO BISECT THE
LOCAL MARINE AREA. SEAS WILL AVERAGE 1-3 FT.
TUESDAY THROUGH FRIDAY...THE STATIONARY FRONT BECOMES DIFFUSE BY
TUESDAY AS A WEAK WAVE OF LOW PRESSURE LIFTS NORTH OF THE MARINE
ZONES. A MORE WELL-DEFINED COLD FRONT WILL APPROACH FROM THE
WEST/NORTHWEST WEDNESDAY AND SHIFT INTO THE MARINE ZONES THURSDAY
AND FRIDAY. ALTHOUGH THE PRESSURE GRADIENT COULD BRIEFLY TIGHTEN
BETWEEN THE APPROACHING FRONTAL TROUGH AND THE SUB-TROPICAL RIDGE
FAR TO THE SOUTHEAST...MARINE CONDITIONS WILL REMAIN WELL BELOW
ANY ADVISORY HEADLINES THROUGH THE PERIOD.
&&
.HYDROLOGY...
PWATS RUNNING 125-130 PERCENT OF NORMAL COUPLED WITH VERY LIGHT
STEERING WINDS IN THE 925-700 HPA LAYER WILL SUPPORT SLOW STORM
MOTIONS AGAIN TODAY. A SLIGHT VEERING WIND PROFILE NOTED ON
VARIOUS POINT FORECAST SOUNDINGS ALSO SUPPORT A POTENTIAL FOR
BACK-BUILDING AND/OR TRAINING...MAINLY ALONG MESOSCALE BOUNDARY
INTERACTIONS. GIVEN THE POTENTIAL IS THERE FOR TORRENTIAL RAINFALL
AND ADDITIONAL FLASH FLOODING...THE FLASH FLOOD WATCH WILL BE
EXTENDED UNTIL LATE THIS EVENING. HIGH RESOLUTION MODELS SHOW A
WEAK WAVE OF LOW PRESSURE FORMING ALONG THE STATIONARY FRONT LATER
THIS MORNING...WHICH WILL ENHANCE LOW-LEVEL CONVERGENCE ALONG THE
COAST AND THE ATTACHED FRONT THROUGH THIS EVENING. THEREFORE THE
HIGHEST FLOOD THREAT WILL LIKELY BE ACROSS THE COASTAL COUNTIES...
EVEN OUTSIDE OF POTENTIAL TIDAL INFLUENCES. HOWEVER...GROUNDS
REMAIN SATURATED FROM SEVERAL DAYS OF INTENSE RAINFALL AND FLASH
FLOODING IS POSSIBLE JUST ABOUT ANYWHERE TODAY ACROSS SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA. GENERAL RAINFALL AMOUNTS OF
1-3 INCHES IS LIKELY THROUGH TONIGHT WITH ISOLATED AMOUNTS
POTENTIALLY EXCEEDING 5 INCHES.
&&
.TIDES/COASTAL FLOODING...
THIS MORNING...TIDES WILL BE VERY CLOSE TO 7.0 FT MLLW IN THE
CHARLESTON HARBOR. GIVEN ALL THE TIDAL AND FRESH WATER LOADING
THAT HAS BEEN ONGOING OVER THE PAST FEW DAYS...SUSPECT SOME PROBLEMS
WILL LIKELY OCCUR CLOSER TO 6.8 FT MLLW...ESPECIALLY IN DOWNTOWN
CHARLESTON. A COASTAL FLOOD ADVISORY WILL BE ISSUED FOR THE
ENTIRE LOWER SOUTH CAROLINA COAST FROM 7 AM UNTIL 10 AM TO COVER
THIS POTENTIAL EVENT. A PEAK TIDE LEVEL OF 6.9-7.1 FT MLLW WILL BE
FORECASTED IN THE CHARLESTON HARBOR.
TONIGHT...TIDES WILL LIKELY BREACH ADVISORY CRITERIA WITH THE
EVENING HIGH TIDE CYCLE IN THE CHARLESTON HARBOR...BUT IT COULD BE
A BIT MORE MARGINAL FOR FORT PULASKI. WILL DEFER THE NEED FOR A
COASTAL FLOOD ADVISORY FOR THE EVENING HOURS TO THE NEXT FORECAST
SHIFT.
LINGERING INFLUENCES FROM THE RECENT PROXIGEAN SPRING TIDE WILL
CONTINUE TO GENERATE ELEVATED TIDES INTO EARLY THIS WEEK. SINCE
ONLY SMALL DEPARTURES ARE NEEDED ABOVE THE PREDICTED ASTRONOMICAL
TIDE VALUES TO RESULT IN AT LEAST SHALLOW COASTAL FLOODING...THIS
WILL LIKELY BOOST TIDE LEVELS ABOVE CRITICAL THRESHOLDS THROUGH
TUESDAY. THE BEST CHANCE FOR COASTAL FLOOD ADVISORIES WOULD BE
DURING THE EVENING HIGH TIDES. SHOULD HEAVY RAIN OCCUR AROUND THE
TIMES OF THE ELEVATED HIGH TIDES...RUNOFF WILL BE INHIBITED AND
MORE SIGNIFICANT FLOODING COULD OCCUR WITHIN THE COASTAL
COMMUNITIES.
&&
.CLIMATE...
RECORD RAINFALL AMOUNTS FOR 11 AUGUST...
KCHS 7.88 INCHES SET IN 1940...
KCXM 7.66 INCHES SET IN 1940...
KSAV 5.86 INCHES SET IN 1919...
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
047>052.
COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
SCZ048>051.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
126 AM EDT MON AUG 11 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH TUESDAY RESULTING IN NUMEROUS SHOWERS AND THUNDERSTORMS.
DRIER AIR WILL WORK INTO THE REGION MID WEEK AND LOWER RAIN
CHANCES.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CONVERGENCE ASSOCIATED WITH THE STALLED FRONT AND HIGH MOISTURE
WILL SUPPORT A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS
OVERNIGHT. HOWEVER...EXPECT LITTLE COVERAGE BASED ON RADAR TRENDS
AND NOCTURNAL COOLING. THE LATEST HRRR DISPLAYS JUST ISOLATED
COVERAGE.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH TUESDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH MONDAY NIGHT. THE MODELS SHOW PRECIPITABLE WATER OVER 2
INCHES. CONVERGENCE ASSOCIATED WITH THE FRONT AND HIGH MOISTURE
SHOULD SUPPORT SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN POSSIBLE
ONCE AGAIN. THE PATTERN SUPPORTS THE HIGHER GUIDANCE MONDAY
THROUGH MONDAY NIGHT. THE NAM AND GFS INDICATE THE H85 FLOW
BECOMING MORE WESTERLY MONDAY NIGHT. CONVERGENCE MAY DIMINISH AND
WITH NOCTURNAL COOLING THE NAM AND GFS MOS APPEAR REASONABLE WITH
POPS LOWERING TO AROUND 30 PERCENT. USED THE COOLER HIGH
TEMPERATURE GUIDANCE AND WARMER LOW TEMPERATURE GUIDANCE BECAUSE
OF CLOUDINESS THROUGH THE PERIOD...WHICH HAS BEEN THE TREND.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS INDICATE THAT A FRONT WILL BE MOVING THROUGH THE CWA ON
WEDNESDAY...THEN STALLING ACROSS THE SRN PORTION OF THE CWA OR
JUST TO THE SOUTH. THIS WILL ALLOW THE CWA TO DRY OUT SOMEWHAT AS
PW VALUES DROP BELOW 1.5 INCHES. THE GFS AND ECMWF DISPLAY THE
STALLED FROM OR TROUGH TO REMAIN IN THE VICINITY OF THE FORECAST
AREA THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW
DEEPER MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. LEANED
TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS FOR THE POP
FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR IFR/LIFR CONDITIONS EARLY THIS MORNING.
FRONTAL BOUNDARY STALLED IN THE CSRA WITH WEDGE CONDITIONS NORTH
OF THE BOUNDARY. WINDS NORTHEAST 5 KNOTS OR LESS OVERNIGHT.
WIDESPREAD MVFR CIGS. HIGH LOW-LEVEL MOISTURE AND NOCTURNAL
COOLING WILL RESULT IN IFR/LIFR CONDITIONS. MODELS INDICATE CIGS
LIFTING TO MVFR LATER THIS MORNING. LOW CONFIDENCE IN TIMING OF CIGS
LIFTING. AS LOW CLOUDS BEGIN TO BREAK UP LATER THIS
AFTERNOON...DIURNAL CONVECTION WILL ONCE AGAIN DEVELOP.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING MVFR TO IFR
RESTRICTIONS IN LOW CLOUDS AND/OR FOG EXPECTED...ALONG WITH HIGH
CHANCES OF MAINLY DIURNAL THUNDERSTORMS THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
346 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 344 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL SHIFT NORTHEAST ACROSS THE REGION
TODAY. THIS COMBINED WITH AN UPPER LEVEL SYSTEM WILL CAUSE PERIODS
OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE AREA TODAY INTO
TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM ALLOWING
FOR DRY WEATHER WEDNESDAY INTO THE END OF THE WORK WEEK. HIGHS
TODAY WILL IN THE MID TO UPPER 70S WITH OVERNIGHT LOWS IN THE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 108 AM EDT MON AUG 11 2014
TRICKY FORECAST FOR THE TAF PERIOD AS MORE ACTIVE WEATHER NEARS
THE AREA. MVFR CONDITIONS LIKELY FOR MOST OF THE PERIOD WITH
FLUCTUATIONS POSSIBLE. WINDS WILL GENERALLY BE BELOW 10 KTS BACKING
FROM THE EAST TO NNW BY THE END OF THE PERIOD.
WEAK SFC LOW ACROSS CENTRAL IN WILL SHIFT NE TODAY AS SHORTWAVE
CURRENTLY ACROSS MISSOURI/IOWA WILL BEGIN TO PHASE WITH UPPER
LEVEL TROF THAT WILL SWING THRU THE AREA TONIGHT INTO TUES. THIS
WILL ALLOW FOR NORTHWARD SURGE OF MOISTURE AND THE RETURN OF SOME
WEAK INSTABILITY. AREA OF SHOWERS AND MVFR BR CURRENTLY ACROSS
CENTRAL IN WILL AFFECT KFWA OVER THE NEXT FEW HOURS WITH CURRENT VFR
CONDITIONS DETERIORATING TO MVFR. ANOTHER AREA OF SHOWERS POPPING
UP TO THE WEST OF SBN WILL AFFECT THE TERMINAL AFTER 9Z. MORE
ROBUST PERIOD OF SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE
DURING THE DAY AND INTO THE LATE AFTERNOON/EVENING HOURS AT BOTH
TERMINALS AS SYSTEM MOVES THRU. BRIEF PERIOD OF IFR CONDITIONS
POSSIBLE IN ANY OF THE HEAVIER SHOWERS/TSRA BUT PINPOINTING TIMING
AND LOCATION AT THIS POINT IS TOO UNCERTAIN FOR INCLUSION. THIS
WILL NEED TO BE MONITORED FOR FUTURE ISSUANCES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...CEO
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
255 AM MDT MON AUG 11 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM MDT SUN AUG 10 2014
VFR CONDITIONS AND LIGHT WINDS SHOULD CONTINUE FOR THE NEXT 24
HOURS. WINDS ARE CALM ACROSS THE REGION PRESENTLY. TEMPERATURES
FELL OFF QUICKLY AND WITH DEWPOINTS IN THE LOW 60S...HAVE A LITTLE
HESITATION THAT THERE MAY BE SOME PATCHY FOG DEVELOPMENT. DID NOT
FEEL CONFIDENT ENOUGH TO PLACE IN TAF WITH HIGH CLOUDS COMING OVER
AND TEMPS RISING 1-2 DEGREES AT KGLD. MODEL GUIDANCE DOES NOT
INDICATE FOG WITH ONLY THE HRRR INDICATING VIS POSSIBLY REACHING 5
MILES. FOR THIS AFTERNOON...A FEW SHOWERS AND STORMS COULD DEVELOP
BUT MOST ACTIVITY SHOULD BE CONFINED TO COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1134 PM MDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 108 PM MDT SUN AUG 10 2014
UPPER FLOW WILL BE NORTHWEST TONIGHT AND MONDAY. SURFACE HIGH
PRESSURE WILL MOVE SOUTH INTO THE CENTRAL PLAINS. OTHER THAN A
SLIGHT CHANCE OF THUNDERSTORMS NEAR THE FRONT OVER WESTERN PORTIONS
OF CHEYENNE AND KIT CARSON COUNTIES IN COLORADO THIS EVENING, POPS WILL BE
NIL. THE NAM SHOWS SOME QPF OVER THE EASTERN FA MONDAY AFTERNOON
BUT FORCING IS VERY WEAK SO WILL ONLY CARRY SILENT POPS.
MIN TEMPERATURES TONIGHT WILL COOL TO AROUND 60. MAX TEMPERATURES
MONDAY WILL RISE TO THE MID 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 408 PM MDT SUN AUG 10 2014
UPPER RIDGE CENTERED OVER THE ROCKIES WILL SUPPRESS MOST
CONVECTION THROUGH MID WEEK. CANNOT RULE OUT AN ISOLATED TO WIDELY
SCATTERED STORM UNDER THE RIDGE AS CIN ERODES IN THE
AFTERNOON...BUT SHOULD BE CONFINED MAINLY IN EASTERN COLORADO
WHERE STORMS HAVE A BETTER CHANCE OF MIGRATING OFF THE FRONT
RANGE. BETTER CHANCES FOR PRECIPITATION RETURNS BEGINNING ON
THURSDAY THROUGH THE REMAINDER OF THE LONG TERM PERIOD AS THE
UPPER RIDGE BREAKS DOWN AND A SERIES OF DISTURBANCES MOVES
THROUGH. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM MDT SUN AUG 10 2014
VFR CONDITIONS AND LIGHT WINDS SHOULD CONTINUE FOR THE NEXT 24
HOURS. WINDS ARE CALM ACROSS THE REGION PRESENTLY. TEMPERATURES
FELL OFF QUICKLY AND WITH DEWPOINTS IN THE LOW 60S...HAVE A LITTLE
HESITATION THAT THERE MAY BE SOME PATCHY FOG DEVELOPMENT. DID NOT
FEEL CONFIDENT ENOUGH TO PLACE IN TAF WITH HIGH CLOUDS COMING OVER
AND TEMPS RISING 1-2 DEGREES AT KGLD. MODEL GUIDANCE DOES NOT
INDICATE FOG WITH ONLY THE HRRR INDICATING VIS POSSIBLY REACHING 5
MILES. FOR THIS AFTERNOON...A FEW SHOWERS AND STORMS COULD DEVELOP
BUT MOST ACTIVITY SHOULD BE CONFINED TO COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JDK
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1157 PM CDT Sun Aug 10 2014
.UPDATE...
Issued at 1157 PM CDT SUN AUG 10 2014
The AVIATION section has been updated for the 06Z TAF issuance.
UPDATE Issued at 837 PM CDT SUN AUG 10 2014
Best surface based moisture and instability remains clustered
across the western edge of the WFO PAH forecast area during the
last 2-3 hours. However, there is some evidence that theta-e
convergence at the low levels is working southeast toward the
confluence of the Mississippi and Ohio Rivers in advance of a weak
surface low centered near Oregon County Missouri at 8 pm CDT.
The current convection appears to be moving from surface based to
elevated in a weak shear environment. The RAP/HRRR guidance
suggests some redevelopment during the overnight hours near the
frontal axis near the upper end of the planetary boundary layer
stretching from Southeast Missouri into southern sections of West
Kentucky. Although tempting to remove any measurable PoPs
overnight, the RAP suggests another wave rotating southeast in the
upper trough through Missouri after midnight. Surface to 850 mb
lapse rates are marginal for convection, as well as low level
(0-3km) shear. At this time, backed off wider coverage of
PoPs/Weather, but did not eliminate at all near the antecedent
frontal boundary overnight. There still seems to be some
maintenance of the multi-cellular convection this evening, so will
leave a small PoP overnight. Given the cloud cover, patchy fog, and
proximity to the old frontal boundary, raised temperatures one to two
degrees into southern sections of West Kentucky,
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 115 PM CDT SUN AUG 10 2014
Area still convection free. However a wave moving across wcntrl MO
appears headed for the CWA. Convection with it not terribly
impressive. Accounted for it with some chance PoPs as it continues
east. Otherwise, some PVA seen in the models overnight, means
keeping chance PoPs going is warranted for showers, maybe a
rumble of thunder. Could see some fog development again tonight
given little change in surface-boundary layer conditions.
Chance PoPs will continue Monday, though will slowly shift east
with time into the afternoon and Monday night with associated weak
forcing. Inherited dry Tuesday and a consensus of the latest data
continues to support that notion for the most part. Dry, cooler
and less humid Tuesday night as high pressure continues to build in.
.LONG TERM...(Wednesday through Sunday)
Issued at 246 PM CDT SUN AUG 10 2014
High pressure over the middle Mississippi valley will keep the
region dry Wednesday into Thursday. Dry and cooler air will
remain in place with continued light north to northeast winds. As
the high moves east, winds will shift back to the south late
Thursday into Friday. Warmer air and increasing dew points can be
expected Friday and through the weekend with temperatures back to
seasonal normals over the weekend. Models are in disagreement and
overall inconsistent dealing with an upper level trof affecting
the PAH forecast area Friday and through the weekend. Models have
backed off precip chances for Friday, so removed any chances for
showers and thunderstorms. The latest ECMWF is much more
aggressive than its previous run and spreads significant precip
across our entire region Friday night into Saturday. The latest
GFS looks more like the much slower previous ECMWF run. Overall
believe chances will slowly increase through the weekend from west
to east, but due to timing uncertainties, kept pops in the chance
to slight chance categories for now.
&&
.AVIATION...
Issued at 1157 PM CDT SUN AUG 10 2014
Elevated showers and thunderstorms are likely to continue
developing over southeast Missouri for the next few hours, and then
stream eastward for much of the overnight hours. KCGI and KPAH
will likely be impacted, but it should stay south of KEVV and
KOWB. The convection may clear KCGI in time to allow some fog
development near sunrise. Elsewhere, it is hard to see anything
more than MVFR fog developing. Cannot rule out an MVFR ceiling
through midday at any terminal, but confidence is too low to
mention at this time. There is a decent signal for at least
scattered thunderstorm development late in the morning and through
much of the afternoon, mainly east of the Mississippi River.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS/DB
LONG TERM...RST
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
312 AM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM EDT MON AUG 11 2014
AT 12Z TUESDAY EXPECT THE SFC LOW OVER LAKE HURON...AND THE
TRIALLING 500MB TROUGH SET UP FROM UPPER MI THROUGH LOWER MI AND
LAKE HURON. UPPER MI WILL BE STUCK BETWEEN THE SFC LOW SHIFTING UP
THROUGH THE CYSB AREA BY LATE AFTERNOON...WHILE A LARGE AREA OF HIGH
PRESSURE AVERAGING 30.0 INCHES IS SET UP FROM N MANITOBA THROUGH
ARKANSAS. WITH THE INCREASED PRESSURE GRADIENT...EXPECT N-NNW WINDS
OF 10-20KTS WITH GUSTS 15-25KTS OVER THE E HALF OF UPPER MI.
SOUNDINGS INDICATE STEADY 25-30KT WINDS JUST ABOVE THE SFC THROUGH
800MB. GIVEN THE BREEZY CONDITIONS...THERE IS A POTENTIAL FOR A HIGH
SWIM RISK FOR MARQUETTE AND ESPECIALLY ALGER COUNTY.
LIGHT RAIN SHOWERS WILL LIKELY LINGER OVER N CENTRAL AND E
UPPER MI THROUGH LATE MORNING...IF NOT LONGER FAR E. RAIN MAY TAKE
THE FORM OF DRIZZLE THANKS TO THE FAVORABLE UPSLOPE CONDITIONS AND
EXPECTED LOWER CLOUDS. 850MB TEMPS AT 12Z TUESDAY WILL BE 7-10C
/COOLEST W/. LOOK FOR THE COOLEST AIR TO SHIFT OVER E UPPER MI
THROUGH THE DAY...MODERATING SLIGHTLY.
A SECONDARY SHORTWAVE DROPPING SE ACROSS UPPER MI COULD PRODUCE
ADDITIONAL CLOUDS AS WELL AS LIGHT SHOWERS/SPRINKLES OVER W AND
CENTRAL UPPER MI TUESDAY NIGHT INTO WEDNESDAY MORNING. WILL LEAVE
THE PERIOD DRY FOR NOW. WITH 850MB TEMPS STILL HOVERING AROUND 10C
ON N-NNW WINDS ON WEDNESDAY...HIGHS SHOULD TOP OUT IN THE UPPER 60S
TO MID 70S. THIS WILL BE APPROX 5F BELOW THE NORMAL VALUE FOR THIS
TIME OF THE YEAR.
THE INCREASING INFLUENCE OF THE SURFACE HIGH WILL BRING GRADUALLY
DIMINISHING WINDS AND MOSTLY CLEAR SKIES FOR WEDNESDAY AFTERNOON
THROUGH FRIDAY NIGHT. EXPECT MOST OF THE UPPER LEVEL DISTURBANCES TO
STAY TO THE E OF THE CWA THROUGH THE END OF THE WORK WEEK...WITH
ANOTHER STRETCH OF DRY WEATHER TUESDAY NIGHT THROUGH AT LEAST
SATURDAY.
LOOK FOR THE 500MB TROUGH TO CENTER ITSELF OVER AND S OF JAMES BAY
TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE SLOWLY SHIFTING TO S QUEBEC
WEDNESDAY NIGHT THROUGH FRIDAY. AS A RESULT...TO NOT EXPECT ANY
SIGNIFICANT WARM UP ACROSS UPPER MI...AS NW FLOW LINGERS ALOFT
THROUGH AT LEAST THE END OF THE WORK WEEK. THE 500MB RIDGE DOES MAKE
ANOTHER APPEARANCE BY THE WEEKEND. DRY WEATHER SHOULD BE THE RULE
FOR SATURDAY. HOWEVER FOR SATURDAY NIGHT AND INTO SUNDAY...LOOK FOR
INCREASING CHANCES FOR PRECIP AS THE SURFACE RIDGE DEPARTS AND AN
UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 130 AM EDT MON AUG 11 2014
AREAS OF RAIN AND POSSIBLY A THUNDERSTORM WILL LOWER CONDITIONS INTO
THE MVFR RANGE BY MON MORNING AT CMX AND IWD. LOWER CLOUDS BEHIND
THE FRONT SHOULD DROP CONDITIONS INTO THE IFR RANGE AT CMX/IWD MON
MORNING AND IN THE AFTERNOON AT SAW. SLOW IMPROVEMENT TO MVFR
CONDITIONS AS RAIN MOVES OUT AT CMX AND IWD MON EVENING BUT
CONTINUES TO LINGER AT SAW WHERE CONDITIONS WILL REMAIN IFR
INTO MON EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN AUG 10 2014
AN UPPER LEVEL TROUGH WILL BE MOVING THROUGH THE UPPER GREAT LAKES
REGION AT THE START OF THE LONG TERM PERIOD AND LEAD TO THE
DEVELOPMENT OF A WEAK LOW OVER EASTERN LOWER MICHIGAN AND LAKE
HURON ON MONDAY NIGHT. THE SLOW SHIFT OF THE UPPER TROUGH AND
SURFACE LOW EAST-NORTHEAST ON MONDAY NIGHT INTO TUESDAY WILL BRING
A GRADUAL DECREASE IN PRECIPITATION/CLOUDS FROM WEST TO EAST
MONDAY NIGHT INTO TUESDAY. WITH DEEP MOISTURE WRAPPING AROUND THE
SURFACE LOW OVER EASTERN UPPER MICHIGAN...EXPECT THE BEST
OPPORTUNITY FOR MODERATE RAINFALL (LIKELY POPS) THERE ON MONDAY
NIGHT. THE CLOUDS SHOULD REMAIN THROUGH THE DAY OVER THE EAST
(MAINLY EAST OF MUNISING/MANISTIQUE) BEFORE DIMINISHING DURING THE
EVENING HOURS AS THE DEEPER MOISTURE DEPARTS. WILL CONTINUE TO HOLD
ONTO CHANCE POPS OVER THOSE EAST AREAS IN THE MORNING AND THEN
SLOWLY END THEM THROUGH THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...PRECIPITATION CHANCES WILL BE DEPENDANT ON HOW QUICKLY
THE LOW LEVEL MOISTURE DEPARTS FROM WEST TO EAST. THINK THE FAR
WESTERN CWA MAY START SEEING SOME BREAKS IN THE CLOUDS DURING THE
EVENING AND EARLY OVERNIGHT HOURS...AS DRIER AIR WRAPS INTO THE
AREA. CLOUDS WILL THEN QUICKLY DIMINISH THROUGH TUESDAY MORNING.
THE CENTRAL CWA WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS THROUGH
TUESDAY MONRING HOURS...ESPECIALLY OVER THE NORTH CENTRAL...WHERE
NORTHERLY WINDS WILL AID UPSLOPE CLOUDS AND DRIZZLE/-RA BEFORE
DIMINISHING IN THE AFTERNOON. IN ADDITION TO THE LOW CLOUDS AND RAIN
SHOWERS...NORTHERLY WINDS WILL BE ON THE INCREASE THROUGH THE NIGHT
AND REMAIN GUSTY THROUGH TUESDAY...ESPECIALLY OVER THE CENTRAL AND
EASTERN CWA...WHERE WINDS WILL GUST TO THE 15-25KT RANGE. THESE
GUSTY WINDS...CLOUDY SKIES...AND TEMPERATURES IN THE 50S WILL
LEAD TO A VERY FALL LIKE START TO TUESDAY OVER PORTIONS OF THE U.P.
FINALLY FOR TUESDAY...THERE IS A POTENTIAL FOR A HIGH SWIM RISK FOR
MARQUETTE AND ESPECIALLY ALGER COUNTY AND WILL ADD A MENTION TO THE
HWO.
FOR THE REST OF THE WORK WEEK...THE UPPER LOW BRIEFLY CLOSES OFF
OVER SOUTHERN QUEBEC AND THE EASTERN GREAT LAKES ON
WEDNESDAY/THURSDAY BEFORE LIFTING NORTHEAST ON FRIDAY. THIS WILL
LEAD TO NORTHWESTERLY FLOW ALOFT AND ALLOW A SURFACE HIGH PRESSURE
RIDGE TO SLOWLY SHIFT EAST ACROSS THE CWA. A SECONDARY SHORTWAVE
DROPPING SOUTHEAST ACROSS THE CWA COULD PRODUCE SOME CLOUDS AND A
FEW SPRINKLES OVER PORTIONS OF WESTERN/CENTRAL UPPER MICHIGAN ON
TUESDAY NIGHT INTO WEDNESDAY MORNING...OTHERWISE EXPECT THE WAVES
TO STAY TO THE EAST OF THE CWA. THE INCREASING INFLUENCE OF THE
SURFACE HIGH WILL BRING GRADUALLY DIMINISHING WINDS AND MOSTLY
CLEAR SKIES FOR WEDNESDAY AFTERNOON THROUGH FRIDAY NIGHT. THE
NORTHERLY FLOW ALOFT WILL KEEP 850MB TEMPS A FEW DEGREES BELOW
NORMAL AND EXPECT THE DAYTIME HIGHS TO BE SIMILAR (ESPECIALLY NEAR
LAKE SUPERIOR). HIGHS OVER INTERIOR LOCATIONS WILL BE IN THE
70S...WHILE LOCATIONS NEAR LAKE SUPERIOR WILL BE IN THE UPPER 60S.
HEADING INTO NEXT WEEKEND...THE UPPER TROUGH THAT COMES ONSHORE OVER
THE PACIFIC NORTHWEST ON TUESDAY WILL BREAK DOWN THE UPPER RIDGE
OVER THE ROCKIES AND SHIFT EAST TOWARDS THE UPPER GREAT LAKES
REGION. LATEST TREND IN THE MODELS IS FOR A LITTLE LATER ARRIVAL
THAN SHOWN YESTERDAY...WHICH SHOULD KEEP MUCH OF SATURDAY DRY AS
THE SURFACE HIGH HOLDS ON. THE PRECIPITATION CHANCES WILL BE ON THE
INCREASE SATURDAY NIGHT AND INTO SUNDAY...AS THE SURFACE RIDGE
DEPARTS AND THE UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 130 AM EDT MON AUG 11 2014
AREAS OF RAIN AND POSSIBLY A THUNDERSTORM WILL LOWER CONDITIONS INTO
THE MVFR RANGE BY MON MORNING AT CMX AND IWD. LOWER CLOUDS BEHIND
THE FRONT SHOULD DROP CONDITIONS INTO THE IFR RANGE AT CMX/IWD MON
MORNING AND IN THE AFTERNOON AT SAW. SLOW IMPROVEMENT TO MVFR
CONDITIONS AS RAIN MOVES OUT AT CMX AND IWD MON EVENING BUT
CONTINUES TO LINGER AT SAW WHERE CONDITIONS WILL REMAIN IFR
INTO MON EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1205 AM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
AN UNSETTLED WEATHER PATTERN EXISTS ACROSS CENTRAL NOAM...WITH A
STRONG WAVE ENTERING WRN HUDSON BAY. THE TROUGH ASSOCIATED WITH THIS
UPPER LOW EXTENDS SOUTH INTO NRN MO. WITHIN THIS TROUGH THERE AREA A
COUPLE OF UPPER LOWS...A WEAKENING ONE OVER CENTRAL MN THAT BROUGHT
THE HEAVY RAINS TO WRN MN LAST NIGHT WITH AN MCV DOWN OVER CENTRAL
IA. AT THE SFC...OBS SHOW A WEAK LOW OVER CENTRAL MN UNDER THE
WEAKENING UPPER LOW. AT 2 PM...THE COLD FRONT EXTENDED SOUTH FROM
THE LOW THROUGH LITCHFIELD...WINDOM...AND INTO NW IA. THE MOST
WIDESPREAD PRECIPITATION THROUGH TONIGHT IS EXPECTED NORTH OF THE
MPX AREA WITH THE CENTRAL MN UPPER LOW AND WELL SOUTH OF MN/WI WITH
THE MCV. WE HAVE SEEN AN UNCAPPED 500-1000 J/KG OF MLCAPE DEVELOP
ALONG THE FRONT...WHICH HAS PROMOTED THE DEVELOPMENT OF A BROKEN
LINE OF STORMS ACROSS MN. HRRR AND MEMBERS 1 AND 3 OF THE HOPWRF
HAVE HAD A GOOD HANDEL ON THINGS TODAY...SO FOLLOWED THOSE MODELS
FOR TRACKING SHOWERS/STORMS ACROSS THE AREA. THIS RESULTED IN
SLOWING THE EWRD PROGRESSION OF POPS INTO WI...WHICH MAKES SENSE AS
ONCE AGAIN WE HAVE SEEN DEWPS OUT EAST DROP INTO THE MID 50S...DRY
AIR OUT THERE HAS BEEN VERY HESITANT TO LEAVE INDEED. BESIDE SLOWING
THE PROGRESSION OF POPS TO THE EAST...ALSO DECREASED POPS OVER WI
OVERNIGHT...AS SHOWERS REALLY LOOK TO LOOSE THEIR DEFINITION AFTER
SUNSET...WITH BEST FORCING WITH THE UPPER LOWS GOING INTO NRN WI AND
NRN IL OVERNIGHT. ALSO RESTRICTED POPS TO JUST WRN WI FOR MONDAY AND
HELD THEM INTO THE CHANCE CATEGORY AS WELL...AS UPPER WAVE DROPPING
DOWN OUT OF CANADA TONIGHT HEADS FOR CENTRAL WI MONDAY AFTERNOON. BY
THEN...BEST MOISTURE WILL BE MAINLY EAST OF THE MPX AREA...WITH
CURRENT REDUCED POPS POSSIBLY EVEN A BIT OVERDONE FOR MONDAY
AFTERNOON.
BESIDE BABYSITTING THE PRECIP ACROSS ERN AREAS TONIGHT...WILL ALSO
HAVE TO WATCH FOR FOG DEVELOPMENT OUT IN WRN MN. WE SAW A GOOD SWATH
OF 1-4+ INCHES OF RAIN OUT THERE OVERNIGHT AND AS WE GO THROUGH THE
NIGHT TONIGHT...SKIES WILL BEGIN TO CLEAR. HOWEVER...THIS CLEARING
WILL ALSO BE ACCOMPANIED BY DECREASING DEWPOINTS AND FAIRLY
PERSISTENT LIGHT NW WINDS. LEFT FOG OUT OF GRIDS FOR NOW THINKING
THESE NW WINDS WOULD KEEP THE ATMO MIXED ENOUGH TO KEEP FOG FROM
FORMING...BUT THEY WILL BE SUSCEPTIBLE TO FOG FORMATION GIVEN THE
RECENT HEAVY RAIN.
FOR MONDAY...OTHER THAN THE THREAT FOR SOME ISO/SCT STORMS OVER WRN
WI IN THE AFTERNOON...IT WILL BE YET ANOTHER STELLAR SUMMER DAY AS
SKIES CLEAR OUT...TEMPS WARM INTO THE MID/UPPER 70S...DEWPOINTS FALL
INTO THE 50S...ALL TOPPED OFF WITH A FRESH NNW WIND THAT WILL BE
GUSTING TO BETWEEN 20 AND 25 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
DRY WEATHER WILL CONTINUE THROUGH MUCH OF THE PERIOD UNTIL WARM
MOIST AIR RETURNS ACROSS THE REGION BY THE END OF THE WEEK. IN THE
MEAN TIME EXPECT LITTLE CHANGE FROM THE WEATHER EXPERIENCED OVER THE
PAST COUPLE OF WEEKS.
FROM A BROAD BRUSHED PERSPECTIVE...IN ORDER TO MAKE A CONFIDENT
FORECAST FOR WIDESPREAD PRECIPITATION ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE WARM SEASON YOU NEED EITHER LARGE SCALE
ASCENT IN THE FORM OF UPPER LEVEL DIVERGENCE...OR MORE COMMONLY LOW
LEVEL CONVERGENCE AND MOISTURE TRANSPORT ACROSS A FRONTAL BOUNDARY
FROM THE LOW LEVEL JET. OVER THE PAST FEW WEEKS NEITHER MN NOR WI
HAVE HAD EITHER...AND AS A RESULT THE WEATHER HAS BEEN NOTICEABLY
DRY.
A 36HR LOOP OF NORTH AMERICAN WATER VAPOR IMAGERY...TOGETHER WITH
GFS 500MB HEIGHTS AND WINDS SHOWED THE ACTIVE STORM TRACK SITUATED
TO THE NORTH ACROSS CENTRAL CANADA...WHILE RECURRING AFTERNOON
CONVECTION FIRED ACROSS THE CENTRAL CONUS ON THE LEE SIDE OF THE
ROCKIES OWING TO UPSLOPE FLOW. AS THE NIGHT PROGRESSED...THE
CONVECTION DRIFTED EASTWARD ACROSS THE PLAIN STATES OF NE AND KS.
ALTHOUGH ISOLATED AREAS OF WESTERN MN DID PICK UP HEALTHY RAINFALL
TOTALS OVER THE PAST 24HRS...THE COVERAGE WAS LIMITED TO A
RELATIVELY SMALL AREA...SIMILAR TO THE ISOLATED HEAVY RAIN THAT FELL
IN WESTERN WI THE PREVIOUS WEEK.
IN THE WAKE OF A WASHED OUT FRONTAL PASSAGE...THE REMAINDER OF THE
WORK WEEK WILL BE DRY AS NORTHWEST FLOW AND SURFACE HIGH PRESSURE
PERSIST ACROSS THE REGION. ON THURSDAY ANOTHER MCS WILL TRICKLE DOWN
THE MISSOURI RIVER VALLEY AND COULD CLIP THE SOUTHWESTERN PART OF
THE CWA. BY THE TIME THE WEEKEND ROLLS AROUND...EXTENDED MODELS
CONTINUE TO SHOW A TRANSITION TO A MORE ZONAL UPPER LEVEL PATTERN
WITH LOW LEVEL MOISTURE RETURNING FROM THE SOUTH. THIS WOULD
INCREASE THE POTENTIAL FOR PRECIP ACROSS THE REGION. IF THIS MODEL
SOLUTION PANS OUT HAVE FAIRLY HIGH CONFIDENCE THAT MOST OF THE
REGION WOULD PICK UP MEASURABLE RAINFALL DURING THE SATURDAY/SUNDAY
TIMEFRAME...BUT WILL NOT GO HIGHER THAN GUIDANCE WITH PRECIP CHANCES
UNTIL WE GET CLOSER TO THE EVENT CONSIDERING THE 12Z ECMWF FOCUSES
THE PRECIP TO THE SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1148 PM CDT SUN AUG 10 2014
CONFIDENCE IS INCREASING FOR IFR OR MVFR CIGS/VISIBILITIES
OVERNIGHT INTO EARLY MONDAY WITH DETERIORATING TRENDS AT TAF
ISSUANCE OVER CENTRAL MN. LOW PRESSURE OVER THE MSP METRO WILL
SLOWLY PUSH EAST OVERNIGHT ALLOWING THE MOISTURE RESPONSIBLE FOR
THE DETERIORATING CONDITIONS NEAR STC TO ROTATE SOUTHEAST. A FEW
SHOWERS ARE ALSO POSSIBLE...PARTICULARLY OVER FAR EASTERN MN AND
WESTERN WI WHICH MAY HELP TO IMPROVE CONDITIONS TEMPORARILY. AXN
AND RWF ARE PROBABLY A BIT TOO FAR WEST TO EXPERIENCE MVFR
CONDITIONS ALTHOUGH THERE IS A SMALL WINDOW LATE TONIGHT AT RWF.
EAU SHOULD REMAIN VFR FOR TONIGHT...BUT COULD DETERIORATE MONDAY
MORNING AS THE LOW PASSES TO THE EAST.
KMSP...VFR AT TAF ISSUANCE TIME...BUT CONDITIONS SHOULD DETERIORATE
QUITE QUICKLY AROUND 06Z WITH QUITE A FEW STATIONS REPORTING CIGS
BETWEEN 010 AND 015 JUST TO THE NORTH. DRIER AIR WILL BEGIN TO
WORK SOUTH BETWEEN 13-14Z...WITH VFR CONDITIONS RETURNING
THEREAFTER.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS W 5-10 KTS.
THU...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1159 PM CDT Sun Aug 10 2014
.MESOSCALE DISCUSSION...
Issued at 602 PM CDT SUN AUG 10 2014
Recent radar trends suggest that thunderstorms are struggling to
expand in coverage despite the presence of boundaries and an
incoming short wave trough from the northwest. The orientation and
movement to the boundaries is likely playing a role in the lack of
coverage. One boundary which extends from near Osceola to
Hartville is moving against low level shear vectors. Low level
destructive interference is likely squashing new updraft
development. A second boundary is more west/east oriented and is
seeping south from extreme northern Bourbon County into the
Osceola area. We have seen weak convection develop along this
feature as shear vectors are oriented more parallel (not
inhibiting updrafts). Another negative across central Missouri is
an overall lack of instability.
As we head into this evening, the current widely scattered
convection will tend to slowly weaken with waning instability. We
will see the continued potential for weaker convective development
as that west/east boundary and upper level wave push south and
east. Overall, we have lowered PoPs over most areas, with the
biggest adjustments to southwestern Missouri and extreme
southeastern Kansas. Any threat for strong to severe storms will
generally occur over the next hour or two and be associated with
convection moving southeast across portions of south-central
Missouri. Despite lower-end deep layer shear, one cell has shown
supercellular structures for the last couple of hours. Thus, we
will maintain a limited hail and wind threat into early this
evening.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 300 PM CDT SUN AUG 10 2014
Warm and humid conditions are in place across the region this
afternoon. Starting to see an uptick in convection during the
past hour, particularly across central Missouri. This is in
response to destabilization due to daytime heating and upper level
energy rotating around an area of low pressure located near Kansas
City. Water vapor imagery and RAP initializations of mid level
vorticity indicate multiple lobes of vorticity emanating from this
upper low. As a result, we should continue to see a gradual
increase in showers and storms across much of the Missouri Ozarks
heading into this evening. The aforementioned upper low and a cold
front moving into the region from the northwest will maintain
scattered showers and storms across the region into much of
tonight. Overnight the better rain chances should begin to shift
to the southeast and east.
High PW air in place (around 1.9" according to the SPC
mesoanalysis page) will result in locally heavy rainfall with this
activity. Deep layer shear remains on the weak side, around 25-30
kt, while both surface based and mixed layer CAPE values are
nearing 3000 J/kg. This should result in a mainly multicell
convective mode with an isolated risk for wet microbursts.
The cold front will exit to the east/southeast on Monday with rain
chances ending during the morning hours.
.LONG TERM...(Monday Night through Sunday)
Issued at 300 PM CDT SUN AUG 10 2014
A nice stretch of weather is expected across the area from Monday
night through Thursday as large area of Canadian surface high
pressure dominates our weather regime. Temperatures will some 7 to
10 degrees below average with comfortable humidity levels.
Temperatures and humidity will rebound back to typical mid-August
values late this week through next weekend as the upper level
pattern flattens a bit. Upper level ridging will attempt to build
into the region from the southwest, meanwhile energy in the
northern stream will threaten to enter from the northwest. Day to
day continuity from individual medium range models have been
lacking (one run wet, the next run dry), however the consensus
suggests that the door will be open to mesoscale convective
systems (MCS) entering from the northwest. As a result, have
continued low end chance PoPs from Friday through the weekend
until finer scale details can be resolved.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1147 PM CDT SUN AUG 10 2014
An approaching upper level disturbance will bring increasing
clouds to the area overnight. The best case scenario is that we
will see scattered areas of MVFR ceilings and perhaps some MVFR
visibilities later tonight. However, some models continue to
indicate the potential for LIFR ceilings and fog late tonight. We
have taken a middle of the road approach at this point and gone
with strictly MVFR ceilings at Joplin and Branson. We did maintain
a TEMPO group for LIFR ceilings at Springfield due to upslope flow
along the Ozark Plateau. Isolated rain showers will also be
possible across the region, but coverage will be too limited to
include in the TAFs. Flight categories will then quickly improve
Monday morning with VFR expected by late morning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Schaumann
SHORT TERM...Gagan
LONG TERM...Gagan
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
556 AM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR HEAVY RAINFALL OVER ALREADY WET GROUND. A
FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA TODAY. A STRONG COLD
FRONT WILL CROSS THE AREA OVERNIGHT WEDNESDAY...BRINGING DRIER
CONDITIONS AND COOLER NIGHT-TIME TEMPERATURES INTO LATE WEEK.
SEASONABLE WEATHER IS EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...NO SIGNIFICANT CHANGES TO FORECAST REASONING
WITH THE DAYBREAK UPDATES. SEVERAL SIGNALS REMAIN IN PLACE FOR A
POTENTIAL OF LOCALIZED BUT SIGNIFICANT FLOODING. NESDIS RELEASED A
SATELLITE PRECIPITATION ESTIMATES MESSAGE FOR THE CHS AND ILM
WARNING AREAS FOR INGREDIENTS IN PLACE FOR POSSIBLE HEAVY RAIN
LATER THIS MORNING. LATEST RADAR TRENDS SHOW CELLS TEAMING UP
OFFSHORE IN WHAT APPEARS TO BE A SHARPENING AXIS OF LOW-LEVEL
CONVERGENCE. KLTX VAD WIND PROFILE SHOWS 25 KT EAST WIND FLOW OFF
THE BALMY ATLANTIC IN THE LOWEST FEW THOUSAND FEET INDUCING AN
INFERRED AND CORRESPONDING INCREASE IN 975-925 MOISTURE TRANSPORT
VECTORS...BUT AS YET RADAR ECHOS REMAIN OVER THE OUTER WATERS. THE
PREVIOUS EARLY MORNING DISCUSSION FOLLOWS.
A FLOOD WATCH IS POSTED FOR NE SC AND SE NC DUE TO THE POTENTIAL
ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS OVER SOGGY GROUND AND
EVEN STANDING WATER AREAS ACROSS OUR ZONES. SATELLITE SENSORS ARE
REGISTERING A POOL OF DEEP COLUMN MOISTURE IN EXCESS OF 2 INCH
PRECIPITABLE WATER VALUE...ACROSS MOST OF THE GULF STATES
EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS POOL WILL
WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE EASTERN
SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT DEEPEN
FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR THROUGH EARLY MONDAY MORNING AS LOW
CIGS...AREAS OF FOG...AND ISOLATED LIGHT SHRA MOVE ACROSS PORTIONS
OF THE AREA. VFR/MVFR ANTICIPATED ON MONDAY WITH SHRA/TSRA.
LATEST RADAR DEPICTS A FEW LIGHT SHOWERS MOVING ABOUT THE FORECAST
AREA...BUT ARE NOT IMPACTING ANY TAF SITES ATTM. ANTICIPATE LOW CIGS
AND AREAS OF FOG TO CREATE MVFR/IFR THROUGH THE OVERNIGHT
HOURS...WITH MAINLY MVFR ALONG THE COAST WITH IFR INLAND. EXPECT
WINDS OVERNIGHT TO BE MAINLY EASTERLY AOB 10 KTS. AFTER
DAYBREAK...EXPECT SHOWERS WITH ISOLATED THUNDERSTORMS THROUGHOUT THE
DAY...CREATING MVFR CONDITIONS AT TIMES THROUGH THE END OF THE VALID
TAF PERIOD DUE TO PERIODS OF LOW CIGS AND LOW VSBYS DUE TO HEAVY
DOWNPOURS AND PATCHY FOG. WINDS WILL BE EAST-SOUTHEAST AOB 10 KTS.
TOWARDS THE END OF THE PERIOD...SHRA/TSRA WILL TAPER OFF AND WINDS
WILL BECOME LIGHT...WITH MVFR POSSIBLE.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. THIS FEATURE WILL INTERACT WITH A HIGH PRESSURE
WEDGE INLAND TODAY AND TONIGHT. A CAUTION STATEMENT CANNOT BE
RULED OUT LATER TODAY OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE
MAY NOT NEED ONE. TSTMS AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE
WATERS AND THIS WILL REDUCE VSBYS LESS THAN 1 NM AT TIMES.
MARINERS SHOULD CONSIDER GETTING A RADAR BRIEFING OR LOOK BEFORE
HEADING OUT TODAY OR TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E
WAVES 3 FEET EVERY 3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10
SECOND INTERVALS. ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK
TUESDAY BUT WIND SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT
DOES REMAIN OVERHEAD OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW/MJC
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC/MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
354 AM EDT MON AUG 11 2014
.SYNOPSIS...
A STALLED FRONT WILL WAVER NEAR THE AREA THROUGH
TUESDAY...CONTINUING THE CHANCE FOR PERIODS OF HEAVY RAINFALL IN
SHOWERS AND THUNDERSTORMS. A FLOOD WATCH IS IN EFFECT FOR THE
ENTIRE AREA TODAY. A STRONG COLD FRONT WILL CROSS THE AREA
OVERNIGHT WEDNESDAY...BRINGING DRIER CONDITIONS. SEASONABLE
WEATHER IS EXPECTED THURSDAY AND INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM MONDAY...A FLOOD WATCH IS POSTED FOR NE SC AND SE
NC DUE TO THE POTENTIAL ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS
OVER SOGGY GROUND AND EVEN STANDING WATER AREAS ACROSS OUR ZONES.
SATELLITE SENSORS ARE REGISTERING A POOL OF DEEP COLUMN MOISTURE
IN EXCESS OF 2 INCH PRECIPITABLE WATER VALUE...ACROSS MOST OF THE
GULF STATES EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS
POOL WILL WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE
EASTERN SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT
DEEPEN FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR THROUGH EARLY MONDAY MORNING AS LOW
CIGS...AREAS OF FOG...AND ISOLATED LIGHT SHRA MOVE ACROSS PORTIONS
OF THE AREA. VFR/MVFR ANTICIPATED ON MONDAY WITH SHRA/TSRA.
LATEST RADAR DEPICTS A FEW LIGHT SHOWERS MOVING ABOUT THE FORECAST
AREA...BUT ARE NOT IMPACTING ANY TAF SITES ATTM. ANTICIPATE LOW CIGS
AND AREAS OF FOG TO CREATE MVFR/IFR THROUGH THE OVERNIGHT
HOURS...WITH MAINLY MVFR ALONG THE COAST WITH IFR INLAND. EXPECT
WINDS OVERNIGHT TO BE MAINLY EASTERLY AOB 10 KTS. AFTER
DAYBREAK...EXPECT SHOWERS WITH ISOLATED THUNDERSTORMS THROUGHOUT THE
DAY...CREATING MVFR CONDITIONS AT TIMES THROUGH THE END OF THE VALID
TAF PERIOD DUE TO PERIODS OF LOW CIGS AND LOW VSBYS DUE TO HEAVY
DOWNPOURS AND PATCHY FOG. WINDS WILL BE EAST-SOUTHEAST AOB 10 KTS.
TOWARDS THE END OF THE PERIOD...SHRA/TSRA WILL TAPER OFF AND WINDS
WILL BECOME LIGHT...WITH MVFR POSSIBLE.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. A CAUTION STATEMENT CANNOT BE RULED OUT LATER TODAY
OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE MAY NOT NEED ONE. TSTMS
AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE WATERS AND THIS WILL
REDUCE VSBYS LESS THAN 1 NM AT TIMES. MARINERS SHOULD CONSIDER
GETTING A RADAR BRIEFING OR LOOK BEFORE HEADING OUT TODAY OR
TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E WAVES 3 FEET EVERY
3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10 SECOND INTERVALS.
ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK TUESDAY BUT WIND
SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT DOES REMAIN OVERHEAD
OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 345 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 PM SUNDAY...
THE GFS FORECASTS CONTINUED...GRADUAL 850MB THETA-E ADVECTION EAST
ACROSS THE REST OF CENTRAL NORTH CAROLINA...AND AS THE RIDGE AXIS
ALOFT MOVES EAST...WEAKLY DIFFLUENT FLOW ALOFT OCCURS INTO MONDAY
NIGHT. OVERALL LIFT IS NOT VERY STRONG...BUT SOME IS FORECAST MONDAY
AND INTO MONDAY EVENING BEFORE THE MODEST LIFT IS FORECAST TO WEAKEN
OVERNIGHT MONDAY. DECENT MEAN MOISTURE IS IN PLACE OVER THE AREA...
AND THE MOISTURE ADVECTION AND THE WEAK DIFFLUENT FLOW ALONG WITH A
SHORTWAVE OR TWO FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA IN
THE MID-LEVELS MONDAY AFTERNOON AND AGAIN MONDAY NIGHT ALL RESULT IN
THE LIKELIHOOD OF SHOWERS IN MOST PLACES WEST OF INTERSTATE 95
MONDAY AND MONDAY EVENING FOLLOWED BY JUST A CHANCE OF RAIN
OVERNIGHT MONDAY AS THE GUIDANCE SUGGESTS AN INCREASE IN SUBSIDENCE
AND LOWER CHANCES. ANTICIPATING AMPLE CLOUD COVER...HAVE FORECAST
HIGHS FOR MOST LOCATIONS A SOLID CATEGORY BELOW THE COOLER MET MOS
GUIDANCE...THOUGH IT WILL BE NOTED THAT THE HIGHS FORECAST FOR
MONDAY...ESPECIALLY IN THE NORTHWEST PIEDMONT ACROSS THE NORTHERN
COASTAL PLAIN...ARE ACTUALLY A CATEGORY HIGHER THAN THE BIAS
CORRECTED MOS GUIDANCE TEMPERATURES. GIVEN THE COOLER
TEMPERATURES... THE CURRENT THINKING IS THAT INSTABILITY AND LIFT
SHOULD PRECLUDE THUNDER...ALTHOUGH IF TEMPERATURES SOMEHOW DO GET
CLOSE TO THE WARMER MOS GUIDANCE VALUES...A THUNDERSTORM OR TWO WILL
BE POSSIBLE. WITH THE SURFACE FRONT ANTICIPATED TO START MOVING
NORTH AS SURFACE HIGH PRESSURE RETREATS...OVERNIGHT LOWS THROUGHOUT
CENTRAL NORTH CAROLINA SHOULD BE WITHIN A DEGREE OR TWO OF 70.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...
TUESDAY AND TUESDAY NIGHT: AN UPPER LEVEL LOW WILL TRAVERSE THE
GREAT LAKES ON TUESDAY AND INTO WEDNESDAY...PUSHING THE UPPER LEVEL
RIDGE EAST AND OFF THE MID-ATLANTIC COAST. ALSO...THE SURFACE
LOW/SHORTWAVE WILL MOVE NE THROUGH THE CENTRAL GREAT LAKES AND INTO
CANADA WITH THE ATTENDANT COLD FRONT APPROACHING NC FROM THE WEST.
MEANWHILE...A SECONDARY LOW WILL DEVELOP ALONG THE SE U.S. COAST
EARLY TUESDAY INCREASING SOUTHWESTERLY FLOW...TEMPERATURE...AND
MOISTURE INTO MUCH OF THE STATE. THOUGH THERE IS STILL A BIT OF
UNCERTAINTY REGARDING THE WEDGE AND HOW LONG IT WILL LINGER...IT
APPEARS THAT THE COLD FRONT WILL MOVE THROUGH MUCH OF THE AREA
TUESDAY NIGHT...WITH SKIES BECOMING LESS CLOUDY AND DRY CONDITIONS
EXPECTED BEHIND IT. FOR NOW WILL KEEP THE CHANCE FOR SHOWERS AND
STORMS ACROSS THE AREA THROUGH MIDNIGHT WEDNESDAY...DECREASING
THEREAFTER. CONVECTIVE PARAMETERS ARE NOT TERRIBLY IMPRESSIVE...
CAPE OF ROUGHLY 500-1000 J/KG (HIGHEST IN THE SE) AND BULK SHEAR IN
THE 20-30 KT RANGE (BEST ACROSS THE NORTH). PW`S WILL CONTINUE TO BE
IN THE 1.5-2 INCH RANGE TUESDAY...DECREASING SIGNIFICANTLY BEHIND
THE FRONT TUESDAY NIGHT. THAT BEING SAID...CANNOT RULE OUT STRONG
STORMS ON TUESDAY...MAINLY IN THE EAST...BUT FOR NOW EXPECT THE MAIN
THREAT TO BE STORMS WITH HEAVY RAIN AHEAD OF THE FRONT. HIGHS MAINLY
IN THE LOW TO MID 80S. OVERNIGHT LOWS WILL DEPEND ON THE PROGRESSION
OF THE FRONT...BUT FOR NOW EXPECT MID 60S NW TO LOW 70S SE.
WEDNESDAY THROUGH SUNDAY: MODELS STILL SUGGEST THE FRONT WILL STALL
ACROSS CENTRAL NC ON WEDNESDAY...WITH LOWER TEMPS AND FEWER CLOUDS
ACROSS THE NW...HIGHS IN THE LOW TO MID 80S. THE FRONT SHOULD MAKE
ITS WAY THROUGH THE AREA WEDNESDAY NIGHT...RESULTING IN LOWS IN THE
UPPER 50S NW TO MID 60S SE. THE UPPER LEVEL LOW WILL REMAIN OVER SE
CANADA/NEW ENGLAND THROUGH THE WEEKEND...WITH THE TROUGH OVER THE
ATLANTIC COAST AND WEST/NORTHWEST FLOW OVER NC. A SURFACE LOW IS
EXPECTED TO LINGER ALONG THE SE ATLANTIC COAST THROUGH SUNDAY...
WITH HIGH PRESSURE TO THE NORTH RIDGING INTO THE AREA. WILL KEEP THE
FORECAST DRY THROUGH SUNDAY...ALTHOUGH IF RAIN SHOULD DEVELOP...
EXPECT IT TO BE MAINLY ALONG THE CAROLINA COAST WHERE IT BECOMES
INCREASINGLY POSSIBLE TOWARD THE END OF THE WEEKEND. HIGHS WILL BE
IN THE LOW TO MID 80S THROUGH THE WEEKEND...WITH LOWS GRADUALLY
INCREASING INTO THE MID TO UPPER 60S BY SATURDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 PM SUNDAY...
SURFACE HIGH PRESSURE CONTINUES TO EXTEND SOUTHWESTWARD FROM THE MID-
ATLANTIC COAST INTO CENTRAL NC THIS EVENING... WITH A STATIONARY
FRONT LOCATED ACROSS SC AND GA. MOIST S TO SE FLOW ATOP THE COOL
STABLE LAYER IS HELPING TO SUPPORT SOME LIGHT TO AT TIME MODERATE
SHOWERS/RAIN ACROSS THE SANDHILLS AND WESTERN PIEDMONT. THE LATEST
HRRR SHOWS THIS ACTIVITY CONTINUING TO LIFT NORTH/NORTHWESTWARD...
AND GENERALLY TO THE NORTH AND WEST OF CENTRAL NC BY 06/07Z. STILL
THINK THAT WE WILL SEE SOME PATCHES OF LIGHT RAIN AND/OR DRIZZLE
OVERNIGHT THOUGH... ESPECIALLY ACROSS THE WESTERN HALF OF THE AREA.
CHANCES OF RAIN AND/OR DRIZZLE SHOULD BE THE LEAST ACROSS OUR
NORTHEAST CLOSER TO THE LOW LEVEL ANTICYCLONE... WHERE BOTH THE GFS
AND NAM WERE SHOWING SOME DRIER AIR AT 850 MB WORKING INTO OUR
NORTHEAST. LOW TEMPS TONIGHT ARE EXPECTED TO RANGE FROM THE MID 60S
NE TO AROUND 70 SOUTH AND SOUTHWEST.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 PM SUNDAY...
THE GFS FORECASTS CONTINUED...GRADUAL 850MB THETA-E ADVECTION EAST
ACROSS THE REST OF CENTRAL NORTH CAROLINA...AND AS THE RIDGE AXIS
ALOFT MOVES EAST...WEAKLY DIFFLUENT FLOW ALOFT OCCURS INTO MONDAY
NIGHT. OVERALL LIFT IS NOT VERY STRONG...BUT SOME IS FORECAST MONDAY
AND INTO MONDAY EVENING BEFORE THE MODEST LIFT IS FORECAST TO WEAKEN
OVERNIGHT MONDAY. DECENT MEAN MOISTURE IS IN PLACE OVER THE AREA...
AND THE MOISTURE ADVECTION AND THE WEAK DIFFLUENT FLOW ALONG WITH A
SHORTWAVE OR TWO FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA IN
THE MID-LEVELS MONDAY AFTERNOON AND AGAIN MONDAY NIGHT ALL RESULT IN
THE LIKELIHOOD OF SHOWERS IN MOST PLACES WEST OF INTERSTATE 95
MONDAY AND MONDAY EVENING FOLLOWED BY JUST A CHANCE OF RAIN
OVERNIGHT MONDAY AS THE GUIDANCE SUGGESTS AN INCREASE IN SUBSIDENCE
AND LOWER CHANCES. ANTICIPATING AMPLE CLOUD COVER...HAVE FORECAST
HIGHS FOR MOST LOCATIONS A SOLID CATEGORY BELOW THE COOLER MET MOS
GUIDANCE...THOUGH IT WILL BE NOTED THAT THE HIGHS FORECAST FOR
MONDAY...ESPECIALLY IN THE NORTHWEST PIEDMONT ACROSS THE NORTHERN
COASTAL PLAIN...ARE ACTUALLY A CATEGORY HIGHER THAN THE BIAS
CORRECTED MOS GUIDANCE TEMPERATURES. GIVEN THE COOLER
TEMPERATURES... THE CURRENT THINKING IS THAT INSTABILITY AND LIFT
SHOULD PRECLUDE THUNDER...ALTHOUGH IF TEMPERATURES SOMEHOW DO GET
CLOSE TO THE WARMER MOS GUIDANCE VALUES...A THUNDERSTORM OR TWO WILL
BE POSSIBLE. WITH THE SURFACE FRONT ANTICIPATED TO START MOVING
NORTH AS SURFACE HIGH PRESSURE RETREATS...OVERNIGHT LOWS THROUGHOUT
CENTRAL NORTH CAROLINA SHOULD BE WITHIN A DEGREE OR TWO OF 70.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...
TUESDAY AND TUESDAY NIGHT: AN UPPER LEVEL LOW WILL TRAVERSE THE
GREAT LAKES ON TUESDAY AND INTO WEDNESDAY...PUSHING THE UPPER LEVEL
RIDGE EAST AND OFF THE MID-ATLANTIC COAST. ALSO...THE SURFACE
LOW/SHORTWAVE WILL MOVE NE THROUGH THE CENTRAL GREAT LAKES AND INTO
CANADA WITH THE ATTENDANT COLD FRONT APPROACHING NC FROM THE WEST.
MEANWHILE...A SECONDARY LOW WILL DEVELOP ALONG THE SE U.S. COAST
EARLY TUESDAY INCREASING SOUTHWESTERLY FLOW...TEMPERATURE...AND
MOISTURE INTO MUCH OF THE STATE. THOUGH THERE IS STILL A BIT OF
UNCERTAINTY REGARDING THE WEDGE AND HOW LONG IT WILL LINGER...IT
APPEARS THAT THE COLD FRONT WILL MOVE THROUGH MUCH OF THE AREA
TUESDAY NIGHT...WITH SKIES BECOMING LESS CLOUDY AND DRY CONDITIONS
EXPECTED BEHIND IT. FOR NOW WILL KEEP THE CHANCE FOR SHOWERS AND
STORMS ACROSS THE AREA THROUGH MIDNIGHT WEDNESDAY...DECREASING
THEREAFTER. CONVECTIVE PARAMETERS ARE NOT TERRIBLY IMPRESSIVE...
CAPE OF ROUGHLY 500-1000 J/KG (HIGHEST IN THE SE) AND BULK SHEAR IN
THE 20-30 KT RANGE (BEST ACROSS THE NORTH). PW`S WILL CONTINUE TO BE
IN THE 1.5-2 INCH RANGE TUESDAY...DECREASING SIGNIFICANTLY BEHIND
THE FRONT TUESDAY NIGHT. THAT BEING SAID...CANNOT RULE OUT STRONG
STORMS ON TUESDAY...MAINLY IN THE EAST...BUT FOR NOW EXPECT THE MAIN
THREAT TO BE STORMS WITH HEAVY RAIN AHEAD OF THE FRONT. HIGHS MAINLY
IN THE LOW TO MID 80S. OVERNIGHT LOWS WILL DEPEND ON THE PROGRESSION
OF THE FRONT...BUT FOR NOW EXPECT MID 60S NW TO LOW 70S SE.
WEDNESDAY THROUGH SUNDAY: MODELS STILL SUGGEST THE FRONT WILL STALL
ACROSS CENTRAL NC ON WEDNESDAY...WITH LOWER TEMPS AND FEWER CLOUDS
ACROSS THE NW...HIGHS IN THE LOW TO MID 80S. THE FRONT SHOULD MAKE
ITS WAY THROUGH THE AREA WEDNESDAY NIGHT...RESULTING IN LOWS IN THE
UPPER 50S NW TO MID 60S SE. THE UPPER LEVEL LOW WILL REMAIN OVER SE
CANADA/NEW ENGLAND THROUGH THE WEEKEND...WITH THE TROUGH OVER THE
ATLANTIC COAST AND WEST/NORTHWEST FLOW OVER NC. A SURFACE LOW IS
EXPECTED TO LINGER ALONG THE SE ATLANTIC COAST THROUGH SUNDAY...
WITH HIGH PRESSURE TO THE NORTH RIDGING INTO THE AREA. WILL KEEP THE
FORECAST DRY THROUGH SUNDAY...ALTHOUGH IF RAIN SHOULD DEVELOP...
EXPECT IT TO BE MAINLY ALONG THE CAROLINA COAST WHERE IT BECOMES
INCREASINGLY POSSIBLE TOWARD THE END OF THE WEEKEND. HIGHS WILL BE
IN THE LOW TO MID 80S THROUGH THE WEEKEND...WITH LOWS GRADUALLY
INCREASING INTO THE MID TO UPPER 60S BY SATURDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BSD
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
400 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
203 AM EDT MON AUG 11 2014
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES WILL MOVE OFF
THE EAST COAST TONIGHT. A WEAK AREA OF LOW PRESSURE AND WARM FRONT
OVER THE LOWER OHIO VALLEY WILL DRIFT NORTHEAST TO THE LOWER GREAT
LAKES BY MONDAY NIGHT. A COLD FRONT FROM THE UPPER MIDWEST WILL
DROP ACROSS THE AREA ON TUESDAY AND HIGH PRESSURE WILL BEGIN TO
BUILD OVER THE REGION ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER WILL INCREASE OVERNIGHT AS THE UPPER LEVEL TROUGH
DEEPENS TO OUR WEST AND SURFACE LOW PRESSURE BECOMES MORE
CONSOLIDATED OVER INDIANA. SHOWERS AND THUNDERSTORMS HAVE BEEN INCREASING
ACROSS SW OHIO WITH A FEW STRAY STORMS DEVELOPING AS FAR NORTH AS
THE BOUNDARY IN THE VICINITY OF I-70. THE TREND OVER THE NEXT FEW
HOURS SHOULD BE FOR STORMS TO DECREASE AS DIURNAL HEATING
WANES...WITH AN UPTICK EXPECTED IN WESTERN/CENTRAL OHIO AFTER
07-08Z WHEN THE WINDS BELOW 700MB VEER TO MORE SOUTHERLY AND
MOISTURE ADVECTION REALLY INCREASES. THE 00Z ILN SOUNDING THIS
EVENING WAS MOISTENING UP WITH PW VALUE ALREADY UP TO 1.79 INCHES.
WE WILL SEE SHOWER INITIATION MAINLY SOUTH OF A LINE FROM BOWLING
GREEN TO MANSFIELD BEFORE 12Z...CONTINUING TO SPREAD NORTH AND
EAST DURING THE MORNING. RAISED POPS ACROSS OUR SW COUNTIES TO
ABOUT 50 PERCENT FOR THE OVERNIGHT PERIOD...AND SPED TIMING OF
PRECIP UP FOR MONDAY FOR ALL BUT EXTREME NE OH/NW PA. 00Z/11 NAM
HAS COME IN AND SUPPORTS BOTH THE HIGHER POPS IN THE SW TONIGHT
AND FASTER TREND ON MONDAY.
PREVIOUS DISCUSSION...
SKIES ARE PARTLY CLOUDY AND WILL REMAIN THAT WAY THROUGH
THE EVENING. SURFACE MOISTURE HAS ALREADY BEGUN TO INCREASE AND
DEW POINTS ARE INTO THE MIDDLE 60S MOST AREAS. THE THREAT FOR
PRECIP WILL BEGIN TO INCREASE IN THE SOUTH AND SOUTHWEST LATE
TONIGHT AS A WARM FRONT APPROACHES. WILL KEEP CHANCE POPS THROUGH
12Z AS IN THE PREVIOUS FORECAST PACKAGE. GIVEN THE CURRENT
DEW POINTS GUIDANCE TEMPS MAY BE A TAD COOL FOR TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
WET WEATHER IS EXPECTED DURING THE PERIOD. MUCH OF THE AREA HAS
GOTTEN DRY SO RAIN IN MANY AREAS WILL BE BENEFICIAL AND WELCOMED.
THE GUIDANCE COMING IN SHOWS PRECIP BLOSSOMING ACROSS NW OH
TOMORROW MORNING. THE PRECIP THREAT WILL REACH THE I-77 CORRIDOR
BY MIDDAY AND ALL BUT NW PA SHOULD BE WET BY LATE AFTERNOON. WILL
BUMP PRECIP CHANCES UP TO CATEGORICAL MUCH OF THE AREA ON MONDAY
AND IN THE EAST ON MONDAY NIGHT. IT DOESN`T APPEAR THAT SEVERE
WEATHER WILL BE AN ISSUE TOMORROW GIVEN A LACK OF SHEAR AND STRONG
LOW LEVEL FORCING. WILL HOWEVER HAVE TO BE CONCERNED ABOUT LOCALLY
HEAVY RAINFALL FROM TRAINING STORMS GIVEN THE WEAK STEERING FLOW
ALOFT. PRECIPITABLE WATER VALUES WILL APPROACH TWO INCHES BY LATE
MONDAY EVENING SO HAVE GONE AHEAD AND ADDED THE MENTION OF HEAVY
RAIN TO THE FORECAST. REALISTICALLY...MOST OF THE AREA SHOULD SEE
AN INCH OR MORE OF RAINFALL BY TUESDAY EVENING. THE PRECIP MAY DIMINISH
LATE MONDAY NIGHT BUT A COLD FRONT MOVING THROUGH ON TUESDAY
SHOULD KICK OFF ANOTHER ROUND OF STORMS. BEST CHANCES WILL BE IN
THE EAST. SOME DRIER AND COOLER AIR MOVING IN ALOFT WILL RESULT IN
BETTER INSTABILITY AND SHEAR BUT ANY SEVERE WEATHER THAT FORMS
SHOULD BE ISOLATED IN COVERAGE. THE WEST WILL DRY OUT ON TUESDAY
NIGHT BUT INSTABILITY SHOWERS AND STORMS WILL BE POSSIBLE IN THE
EAST THROUGH WEDNESDAY. HIGH PRESSURE WILL THEN WIN OUT FOR GOOD.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD. TOMORROW
WILL BE RATHER MUGGY BUT THE REMAINDER OF THE PERIOD WILL SEE
BELOW NORMAL READINGS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER LEVEL LOW WILL REMAIN OVER MUCH OF THE REGION THROUGH THE
FORECAST PERIOD. A FEW WEAK WAVES WILL ROTATE THROUGH THE TROF
DURING THE EXTENDED PERIOD. THE GFS HINTS AT WEAK SYSTEM MOVING
ACROSS THE FORECAST AREA ON THURSDAY. MODELS ARE INDICATING VERY
LIMITED MOISTURE WITH WHAT APPEARS TO BE A WEAK BACK DOOR COLD
FRONT. I WILL NOT MENTION PRECIPITATION WITH THE SYSTEM AT THIS
TIME. A RETURN FLOW WILL ESTABLISH ITSELF LATE NEXT WEEK AND A WARM
FRONT WILL MOVE NORTHWARD. THIS SYSTEM COULD BRING SOME SCATTERED
SHOWERS AND THUNDERSTORMS LATE SATURDAY OR SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
EASTERLY FLOW OVERNIGHT WILL BECOME SOUTHEAST TOWARDS MONDAY
MORNING. AS A SURFACE LOW PRESSURE SYSTEMS DEVELOPS TO THE WEST
OF THE LAKE ON MONDAY EVENING...THE SOUTHEAST FLOW WILL INCREASE. A
COLD FRONT WILL SWEEP ACROSS THE LAKE ON TUESDAY BRINGING A WEST TO
NORTHWEST FLOW THROUGH MID WEEK. WINDS OVERNIGHT MAY INCREASE TO
NEAR 20 KNOTS AND WAVES MAY INCREASE TO NEAR 4 FEET OVER THE WESTERN
BASIN. MY INITIAL THINKING IS THAT CONDITIONS WILL REMAIN BELOW
SMALL CRAFT. THE DURATION OF THE STRONGER EASTERLY WINDS ARE ONLY A
FEW HOURS BEFORE IT BECOMES MORE SOUTHEAST. THIS SHOULD NOT ALLOW
THE WAVES TO BUILD ABOVE SMALL CRAFT ADVISORY CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KEC/KUBINA
SHORT TERM...KUBINA
LONG TERM...GARNET
AVIATION...KIELTYKA
MARINE...GARNET
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
1035 PM PDT SUN AUG 10 2014
UPDATED AVIATION DISCUSSION
.UPDATE...THUNDERSTORMS HAVE DEVELOPED IN THE SOUTHERN FRINGE OF
THE FORECAST AREA THIS EVENING WITH THE BULK OF THE ACTIVITY IN
DESCHUTES COUNTY SOUTH OF BEND. THUNDERSTORMS HAVE NOT BEEN
PARTICULARLY STRONG AND APPEAR TO BE WEAKENING AS SUNDOWN
APPROACHES. HOWEVER, THE LATEST RUN OF THE HRRR MODEL SHOWS
ANOTHER BAND OF THUNDERSTORMS ARRIVING IN DESCHUTES COUNTY FROM
THE SOUTH AROUND MIDNIGHT. THUNDERSTORMS ARE SHOWN MOVING AS FAR
NORTH AS NORTHERN JEFFERSON COUNTY A COUPLE OF HOURS LATER SO HAVE
EXPANDED THE AREA OF ISOLATED THUNDERSTORMS OVERNIGHT FURTHER
NORTH. HAVE ALSO ADJUSTED SKY COVER TO MATCH CURRENT TRENDS AND
THE POSSIBLE THUNDERSTORMS LATER TONIGHT. FORECAST IS OTHERWISE IN
GOOD SHAPE. UPDATE WILL BE OUT SHORTLY. PERRY
&&
.AVIATION...06Z TAFS...AN UPPER LEVEL LOW WILL REMAIN OFF THE
CENTRAL CALIFORNIA COAST FOR THE NEXT 24 HOURS. THIS WILL SEND
MOISTURE INTO OUR AREA AND ADD TO THE INSTABILITY DUE TO DAYTIME
HEATING. THUNDERSTORMS ARE WINDING DOWN FOR TONIGHT THOUGH AN
ISOLATED STORM OR TWO REMAINS POSSIBLE AT KRDM AND KBDN AND HAVE
VCTS THROUGH 08Z AT THOSE SITES. BKN-OVC CEILINGS ABOVE 7000 FEET
AGL WILL CONTINUE THERE FOR A FEW HOURS BEFORE PARTIALLY CLEARING
OUT. THE REST OF THE AREA WILL BE CLEAR OVERNIGHT. THUNDERSTORMS
WILL BEGIN DEVELOPING IN CENTRAL OREGON AFTER 20Z AND WILL SPREAD
NORTH ACROSS THE REGION BY 00Z. ALL TAF SITES HAVE VCTS AFTER
20Z-22Z DEPENDING ON THE SITE. STORMS WILL BE HIGH BASED AND DO NOT
EXPECT CEILINGS TO DROP BELOW 7000 FEET AGL. SURFACE WINDS WILL
REMAIN BELOW 12 KTS FOR THE NEXT 24 HOURS EXCEPT AROUND
THUNDERSTORMS. THUNDERSTORMS MAY HAVE GUSTY WINDS TO 40 KTS. PERRY
&&
.PREV DISC... /ISSUED 337 PM PDT SUN AUG 10 2014/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. CUMULUS STARTING TO
FORM OVER THE HIGHER TERRAIN OF CENTRAL AND NORTHEAST OREGON EARLY
THIS AFTERNOON. IF THE TREND CONTINUES SHOULD SEE ISOLATED SHOWERS
AND THUNDERSTORMS DEVELOP LATE AFTERNOON INTO THE EVENING. THIS IS
IN RESPONSE TO A LARGE UPPER LOW JUST OFF THE CALIFORNIA COAST AND
INCREASING INSTABILITY. 18Z NAM INDICATES SOME ACTIVITY COULD
CONTINUE OVERNIGHT FOR CENTRAL OREGON. NORTH OF THIS AREA SKIES
SHOULD REMAIN MOSTLY CLEAR THROUGH THE EVENING AND TONIGHT. THE
UPPER LOW REMAINS NEARLY STATIONARY ALONG THE CALIFORNIA COAST
MONDAY HOWEVER THE UPPER LEVEL FLOW BECOMES MORE SOUTHERLY OVER OUR
FORECAST AREA. THIS SHOULD ALLOW CONVECTION TO MOVE NORTHWARD DURING
THE DAY AND INTO MONDAY NIGHT. MORE ENHANCEMENT FROM THE JET COULD
PRODUCE SOME STRONGER STORMS TOMORROW AS WELL. THE LOW WEAKENS A BIT
AND MOVES NORTHEAST ACROSS THE REGION TUESDAY AND SHOULD BRING MORE
WIDESPREAD SHOWERS AND THUNDERSTORMS. ON WEDNESDAY ANOTHER UPPER LOW
MOVES ACROSS THE PACIFIC NORTHWEST WITH ADDITIONAL SHOWERS AND
STORMS. AS FOR TEMPERATURES MONDAY WILL BE HOT WITH 90S TO NEAR 100.
COOLER TUESDAY WITH 80S TO LOWER 90S. EVEN COOLER WEDNESDAY WITH 70S
AND 80S. 94
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY NIGHT...A CLOSED UPPER
LEVEL LOW IS PROGGED TO SLOWLY MOVE EAST ACROSS THE AREA WEDNESDAY
NIGHT AND BE MAINLY OUT OF THE AREA BY EARLY SATURDAY MORNING. THIS
WILL RESULT IN A MUCH WETTER PERIOD DURING THE EXTENDED RANGE WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. GIVEN THE POTENTIAL PROJECTED PRECIPITATION WITH THE SYSTEM
AS IT PASSES THROUGH...THERE IS GOING TO BE SOME FLASH FLOOD
CONCERNS OVER THE NUMEROUS BURN SCARS WITHIN THE CWA IF ANY STORMS
DEVELOP AND TRANSITION OVER THOSE AREAS. THIS WILL NEED TO BE
MONITORED AS THE EVENT APPROACHES. WRAP AROUND MOISTURE MAY LINGER
BEHIND THE SYSTEM TO BRING SOME SHOWERS TO THE NORTHERN BLUE AND
WALLOWA MOUNTAINS EARLY FRIDAY MORNING BEFORE MOISTURE CLEARS OUT OF
THE AREA BY SATURDAY MORNING. A BRIEF SHORTWAVE RIDGE NUDGES INTO
THE AREA SATURDAY AND SUNDAY FOR A BRIEF DRYING TREND BEFORE MORE
MOISTURE AHEAD OF A POTENTIAL SHORTWAVE TROUGH ENCROACHES SUNDAY
EVENING. HIGH TEMPERATURES DURING THE PERIOD WILL BE IN THE MID 70S
TO MID 80S EXCEPT MID 60S TO MID 70S MOUNTAINS ON WEDNESDAY WITH
TEMPERATURES WARMING BACK UP INTO THE MID 70S TO UPPER 80S BY SUNDAY
AFTERNOON. BIEDA
FIRE WX...A LOW PRESSURE SYSTEM OFF THE COAST OF NORTHERN
CALIFORNIA WILL CONTINUE TO BRING MOISTURE FURTHER NORTH INTO THE
REGION EACH DAY. THIS WILL LEAD TO INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS. A RED FLAG WARNING FOR CENTRAL OREGON AND THE
SOUTHERN BLUE AND STRAWBERRY MOUNTAINS IS IN EFFECT STARTING THIS
AFTERNOON AND RUNNING THROUGH TUESDAY EVENING. THE CHANCE OF
THUNDERSTORMS WILL SPREAD NORTH AND EASTWARD ON MONDAY. THEREFORE A
RED FLAG WARNING HAS BEEN ISSUED STARTING MONDAY LATE MORNING AND
RUNNING THROUGH TUESDAY EVENING FOR THE EAST SLOPES OF THE OREGON
AND WASHINGTON CASCADES AND NORTHEAST OREGON MOUNTAINS. A FIRE
WEATHER WATCH REMAINS FOR THE COLUMBIA BASIN FOR THE POTENTIAL OF
THUNDERSTORMS MONDAY EVENING THROUGH TUESDAY. THESE THUNDERSTORMS
WILL START OUT WITH LITTLE TO NO RAINFALL. EXPECT PRECIPITATION
CHANCES TO INCREASE MONDAY AND TUESDAY. A TROUGH OF LOW PRESSURE
WILL MOVE INTO THE REGION TUESDAY INTO WEDNESDAY...WITH BREEZY WINDS
EXPECTED IN THE CASCADE GAPS TUESDAY AND WEDNESDAY AFTERNOONS. THE
POTENTIAL FOR THUNDERSTORMS WILL CONTINUE THROUGH THE MIDWEEK AS THE
TROUGH SLOWLY MOVES THROUGH THE REGION. DMH
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 64 99 70 88 / 0 10 20 30
ALW 66 100 72 90 / 0 10 20 30
PSC 62 102 69 92 / 0 10 20 30
YKM 60 99 71 87 / 0 10 20 30
HRI 60 100 68 91 / 0 10 20 30
ELN 59 99 67 88 / 0 10 20 30
RDM 57 93 61 85 / 20 30 30 40
LGD 57 94 61 86 / 10 30 30 40
GCD 59 95 60 86 / 20 30 30 40
DLS 63 100 70 87 / 0 20 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY ORZ041.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ506-509-511.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
ORZ049-050-502-503-507.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
ORZ041-044-503-507-508-510.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ505-510.
WA...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
WAZ024-520-521.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY WAZ030.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
WAZ024-026>029-521.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/98/83/84
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 AM EDT MON AUG 11 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH OF OUR REGION THROUGH
MONDAY NIGHT. A SERIES OF LOW PRESSURE CENTERS WILL MOVE EAST ALONG
THE FRONT...MAINTAINING ELEVATED CHANCES OF SHOWERS AND
THUNDERSTORMS UNTIL THEN. A COLD FRONT WILL THEN CROSS THE AREA ON
TUESDAY WITH DRIER AIR MOVING OVER THE AREA IN ITS WAKE.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST...THOUGH THE UPPER FLOW IS BECOMING LESS CONFLUENT ABOVE IT
THANKS TO THE TROUGH MOVING INTO THE GREAT LAKES. IT SHOULD WEAKEN
AND MOVE OFFSHORE TODAY. HOWEVER THE INCUMBENT WEDGE IS UNLIKELY TO
GO ANYWHERE THIS MORNING EVEN AS THE HIGH LOSES ITS GRIP ON OUR
REGION. WEAK UPGLIDE WILL CONTINUE BUT THAT APPEARS TO BE BARELY
CAPABLE OF PRODUCING ANYTHING MORE THAN DRIZZLE. THE RAIN BEING
REPORTED BY A HANDFUL OF OBS SITES ATTM SEEMS TO BE FORCED BY
UPSLOPE. VAD WINDS FROM KGSP/KCLT INDICATE LIGHT SELY FLOW IN THE
FEW THSD FT ABOVE THE ELY FLOW WITHIN THE WEDGE. OVERNIGHT POP
TRENDS FOCUS MOSTLY IN THE NC BLUE RIDGE AREA. THE HRRR AND 00Z
HIRES NCEP WRF RUNS BACK UP THE UPSLOPE CONCEPT...ALLOWING CONTINUED
SHOWER DEVELOPMENT IN THAT AREA.
WITH THE ISENTROPIC LIFT BEING UNIMPRESSIVE AND WITH DRYING
OCCURRING ALOFT...THE LOW STRATUS WILL BEGIN TO LIFT ONCE INSOLATION
GETS UNDERWAY...BUT SKIES WILL REMAIN NEARLY OVERCAST OVER MOST OF
THE CWFA TODAY. THIS IS PARTICULARLY TRUE OF THE NW NC PIEDMONT
WHERE THE WEDGE IS PROGGED TO REMAIN STRONGEST. POPS WILL INCREASE
WITH THE HEATING...THE INSTABILITY LOOKING MUCH MORE CAPABLE OF
DRIVING PRECIP THAN THE LINGERING UPGLIDE. THUNDER CHANCES DO RETURN
FOR MOST OF THE AREA BY LATE AFTN...PER CONSENSUS OF GFS/NAM
PRODUCING NEAR 1000 J/KG OF CAPE. SHEAR WILL BE SUFFICIENT TO ALLOW
LOOSE ORGANIZATION INTO CLUSTERS IF TSRA DO BREAK OUT...BUT SEVERE
THREAT IS QUITE LOW. PWATS REMAIN NEAR 2 INCHES SO LOCALLY HEAVY
RAIN IS OF SOME CONCERN HOWEVER.
MORE DETAILS TO COME WITH FULL PACKAGE DISCUSSION AT 330 AM.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 245 PM SATURDAY...EARLY TUESDAY...A MID LEVEL TROF IS EXPECTED
TO AMPLIFY WEST OF THE FORECAST AREA. THE GFS INDICATES THAT TWO S/W
WILL RIPPLE ACROSS THE REGION BY 18Z TUESDAY. H85 WINDS WILL REMAIN
WSW DURING THE MORNING...THEN VEER FROM THE WEST DURING THE
AFTERNOON. I WILL FORECAST 30 TO 40 POPS DURING THE PASSAGE OF THE
MORNING S/W. 30 TO 40 POPS MAY VERIFY WELL DURING THE AFTERNOON AS
CAPES POOL ABOVE 1000 J/KG AHEAD OF A COLD FRONT. USING A BLEND OF
PREFERRED MOS...I WILL FORECAST HIGHS OF 80 WITHIN THE MTN VALLEYS
TO MID TO UPPER 80S EAST OF I-85. TUESDAY NIGHT...THE COLD FRONT
WILL SLIDE ACROSS THE CWA...ENDING ANY MENTIONABLE POPS. DRY HIGH
PRESSURE WILL BUILD OVER THE REGION THROUGH THE DAY. I WILL FORECAST
SINGLE DIGIT POPS AND LOWER AFTERNOON HUMIDITY. HIGH TEMPERATURES
WILL LIKELY RANGE VERY CLOSE TO TUES VALUES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 2 PM SUNDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
THURSDAY WITH BROAD UPPER TROFFING CENTERED TO OUR NORTH AND UPPER
RIDGING OVER THE EASTERN ROCKIES. THE LONG RANGE MODELS INDICATE
THAT THE TROF WILL BEGIN TO LIFT OVER THE WEEKEND AND BY NEW DAY 7
ON SUNDAY...THE UPPER PATTERN WILL HAVE FLATTENED OUT OVER THE SE
REGION.
AT THE SFC...DRY HIGH PRESSURE IS EXPECTED TO BE SPREADING OVER THE
CAROLINAS BY THE START OF THE PERIOD. AN AREA OF NEAR SFC
CONVERGENCE WILL LIKELY SETUP JUST TO OUR SOUTH EARLY IN THE PERIOD
BUT IS EXPECTED TO REMAIN SOUTH OF THE CWFA. ITS LOOKING LIKE THE
BERMUDA HIGH WILL BEGIN TO STRENGTHEN AGAIN BY THE END OF THE PERIOD
AND WE WILL RETURN TO A MORE TYPICAL SLY FLOW REGIME BEYOND DAY 7.
NO OTHER SIGNIFICANT PATTERN CHANGES ARE EXPECTED THRU THE MEDIUM RANGE.
AS FOR THE SENSIBLE FCST...WE SHOULD BE MOSTLY DRY FOR
THURS...FRI...AND SAT WITH ONLY SOME BRIEF SLIGHT CHANCE POPS FOR
THE HIGHER TERRAIN FRI AND SAT AFTERNOON/EVENING. WITH THE RETURN OF
MORE MOIST SLY FLOW EXPECTED BY SUN...POPS WILL INCREASE TO A MORE
TYPICAL SLIGHT CHANCE TO SOLID CHANCE PATTERN TYPICAL OF LATE
SUMMERTIME. TEMPS WERE NOT CHANGED MUCH WITH VALUES GRADUALLY
WARMING THRU THE PERIOD BUT LIKELY REMAINING JUST BELOW CLIMATOLOGY
FOR MID AUGUST.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...IN CONTINUING WEAK WEDGE REGIME...IFR CIGS ARE A NEAR
CERTAINTY UNTIL A FEW HRS AFTER SUNRISE. PERIODS OF DRIZZLE AND A
FEW SHOWERS WILL BE NEARBY EARLY THIS AM. SAID PRECIP COULD CAUSE
IFR VSBY AT TIMES. THE CONTINUALLY WEAKENING WEDGE AND INSOLATION
SHOULD PERMIT CIGS TO LIFT TO MVFR BY MIDDAY...BUT THOSE CIGS WILL
LAST INTO TONIGHT. SUFFICIENT INSTABILITY SHOULD BE REALIZED TO
ALLOW A FEW TSRA TO FORM THIS AFTN...EACH OF WHICH WILL BE CAPABLE
OF TORRENTIAL RAIN. EASTERLY WINDS WILL PREVAIL...MAINLY BEING SOUTH
OF EAST AFTER DAYBREAK.
ELSEWHERE...MORE OR LESS AS AT KCLT THOUGH WITH MOST OF THE PRECIP
OCCURRING NEAR THE NC BLUE RIDGE. KHKY WILL BE MOST IMPACTED WITH
VSBY RESTRICTIONS. IFR CIGS WILL LAST OVERNIGHT WITH PATCHY MVFR TO
IFR FOG ALSO LIKELY...AS WELL AS THE PATCHY DRIZZLE. THE WEAKENING
INFLUENCE OF THE WEDGE MEANS PRECIP CHANCES TODAY WILL BECOME MORE A
FUNCTION OF INSTABILITY AND UPSLOPING...BUT THE BEST OVERALL CHANCE
IS OVER NC WHERE ALL THREE ARE A FACTOR TO SOME DEGREE. VCSH/VCTS
USED SPARINGLY WITH PROB30S ASSIGNED DURING THE PEAK CHANCE PERIODS.
WITHIN THE WEDGE...KHKY WILL SEE MAINLY NE WINDS TODAY WITH THE
OTHER SITES PREVAILING SELY. ANY CIGS AT SUNSET WILL LIKELY PERSIST
THRU 06Z.
OUTLOOK...SOME RESTRICTIONS ARE LIKELY WITHIN LOW CLOUDS AND OCNL
SHOWERS THROUGH AT LEAST MONDAY EVENING AND PERHAPS INTO TUESDAY
WHEN A COLD FRONT WILL PASS THROUGH. DRIER AND VFR CONDITIONS SHOULD
RETURN IN ITS WAKE AND CONTINUE THROUGH LATE WEEK.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT MED 76% MED 75% HIGH 87% MED 79%
KGSP MED 79% HIGH 83% HIGH 84% HIGH 96%
KAVL HIGH 86% HIGH 80% HIGH 89% HIGH 81%
KHKY HIGH 82% HIGH 88% HIGH 87% MED 79%
KGMU HIGH 80% HIGH 84% HIGH 84% HIGH 96%
KAND MED 70% MED 75% MED 67% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...NED
LONG TERM...JPT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1129 PM CDT SUN AUG 10 2014
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 859 PM CDT SUN AUG 10 2014/
DISCUSSION...00Z UPPER AIR ANALYSIS THIS EVENING PLACES A 500 MB
MID LEVEL TROUGH AXIS LOCATED ACROSS THE UPPER MIDWEST AND
PORTIONS OF MISSOURI AND EAST KANSAS. REGIONAL WSR-88D RADAR
TRENDS INDICATE INCREASED COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST MISSOURI
AND NORTH CENTRAL ARKANSAS THIS EVENING IN RESPONSE TO THIS MID
LEVEL SHORTWAVE TROUGH. LATEST MESOANALYSIS YIELDS SURFACE BASED CAPE
VALUES AROUND BETWEEN 2000-2500 J/KG...SURFACE BASED LI/S AROUND
-6. LATEST SHORT TERM TRENDS INCLUDING THE 11/00Z HRRR RUN
INDICATE A POTENTIAL FOR UPSTREAM SHOWERS AND THUNDERSTORMS TO
MOVE INTO PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL IN THE NEXT FEW HOURS AND SPREAD ACROSS THE REMAINDER OF
THE MID SOUTH OVERNIGHT. WILL MAKE ADJUSTMENTS TO RAIN CHANCES TO
ACCOUNT FOR SHORT TERM CONVECTIVE TRENDS AND ADJUST ANY OTHER
ELEMENTS AS NEEDED.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 624 PM CDT SUN AUG 10 2014/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 316 PM CDT SUN AUG 10 2014/
A STATIONARY FRONT CURRENTLY STRETCHES ACROSS SOUTHERN MISSOURI
THIS AFTERNOON. THIS FRONT WILL SLIDE INTO THE MIDSOUTH ON MONDAY
AS A COLD FRONT. SHOWERS AND THUNDERSTORMS ARE BEGINNING TO FIRE
ALONG THE FRONT. THESE SHOWERS AND THUNDERSTORMS MAY DEVELOP INTO
A LINE LATER THIS EVENING. THE LINE MAY BEGIN TO PUSHING INTO
NORTHEAST ARKANSAS LATE TONIGHT INTO THE EARLY MORNING HOURS.
MEANWHILE...EXPECT DIURNAL SHOWERS AND THUNDERSTORMS THAT ARE CURRENTLY
OCCURRING NEAR THE TENNESSEE RIVER AND ACROSS NORTHWEST
MISSISSIPPI TO DIE OUT DURING THE EARLY EVENING HOURS. ANOTHER
HUMID NIGHT IS EXPECTED ACROSS THE MIDSOUTH. LOWS WILL BE IN THE
LOWER TO MID 70S.
EXPECT SOME LINGERING CONVECTION MONDAY MORNING ACROSS NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL AND WEST TENNESSEE FROM IS LEFT
OF LINE THAT MOVES IN DURING THE OVERNIGHT HOURS AHEAD OF THE
APPROACHING COLD FRONT. REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS
WILL OCCUR ALONG THE COLD FRONT MONDAY AFTERNOON. SOME STORMS MAY
BECOME SEVERE PRODUCING LARGE HAIL...DAMAGING WINDS...AND FLASH
FLOODING. HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S.
THE COLD FRONT WILL CONTINUE TO PUSH SOUTHWARD MONDAY NIGHT.
LINGERING CHANCES FOR SHOWERS AND THUNDERSTORMS WILL OCCUR MAINLY
ACROSS WEST TENNESSEE NEAR THE MISSISSIPPI BORDER INTO NORTH
MISSISSIPPI. COOLER AND DRIER AIR MAY BEGIN TO FILTER INTO THE
MISSOURI BOOTHEEL...NORTHEAST ARKANSAS...AND NORTHWEST TENNESSEE
DURING THE EARLY MORNING HOURS.
TUESDAY THROUGH FRIDAY WILL BE BEAUTIFUL ACROSS THE MIDSOUTH. SFC
HIGH PRESSURE WILL MOVE INTO THE AREA FROM THE UPPER MIDWEST. EXPECT
COOLER TEMPERATURES WITH LOW HUMIDITY AND PLENTY OF SUNSHINE.
HIGHS WILL BE IN THE 80S WITH LOWS IN THE MID 50S TO MID 60S.
PATTERN BECOMES UNSETTLED ONCE AGAIN BY NEXT WEEKEND AS SFC HIGH
SHIFTS EAST. WEAK NORTHWEST FLOW ALOFT WILL ALLOW A COUPLE OF
DISTURBANCES TO MOVE THROUGH THE REGION SETTING OFF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. HUMIDITY WILL ALSO RETURN TO
THE AREA.
KRM
&&
.AVIATION...06Z TAF CYCLE
NO THUNDERSTORMS ARE EXPECTED AT ANY TAF SITE FOR THE NEXT SEVERAL
HOURS. EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD ALTHOUGH
SOME MVFR CIGS AND VIS ARE POSSIBLE LATE TONIGHT/EARLY TOMORROW.
AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL APPROACH THE
REGION LATER TONIGHT AND MONDAY MORNING. AS A RESULT EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP THOUGH TIMING IS A
PROBLEM SO OPTED TO CONTINUE VCTS FOR NOW STARTING LATER TONIGHT.
EXPECT SOME LIGHT FOG AT KMKL AND KTUP LATER TONIGHT. WINDS WILL BE
GENERALLY LIGHT FROM THE SW/WSW.
STORMS SHOULD COME TO AN END DURING THE EARLY TO MIDDLE PART OF THE
AFTERNOON AT JBR....MEM...THEN MKL AS THE FRONT PASSES. WINDS WILL
SHIFT FROM THE NORTHWEST. UNLESS THE FRONT STALLS...IT SHOULD
MOVE THROUGH TUP AFTER SUNSET.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1207 AM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND OVER
THE EASTERN GREAT LAKES...WHILE TROUGHING WAS DROPPING SOUTH THROUGH
SOUTH CENTRAL CANADA. TWO OTHER SHORTWAVE TROUGHS WERE EVIDENT OVER
NORTHERN MN AND SOUTHERN IOWA. BOTH OF THESE SHORTWAVE TROUGHS WERE
PRODUCING SHOWERS AND SOME THUNDERSTORMS...BUT SO FAR THEY HAVE
STAYED WEST OF THE FORECAST AREA. THIS IS DUE TO HIGH PRESSURE
REMAINING IN PLACE OVER THE GREAT LAKES...PROVIDING A FLOW OF DRY
AIR INTO THE REGION. GOES PRECIPITABLE WATER IMAGERY DEPICTED THE
DIFFERENCE IN MOISTURE WELL...RANGING FROM 1-1.25 INCHES OVER THE
FORECAST AREA TO 1.5-1.75 INCHES FROM NORTH CENTRAL MN INTO WESTERN
IOWA AND MISSOURI. THE DRIER AIRMASS OVER THE FORECAST AREA HAS LED
TO A MOSTLY SUNNY DAY...AMD WITH 850MB TEMPS OF 12-14C ON 12Z
RAOBS...TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S/LOW 80S. IN THE
SEA LEVEL PRESSURE FIELD...MAIN ITEM TO NOTE IS A COLD FRONT
TRACKING ACROSS WESTERN MN AHEAD OF THE SOUTH CENTRAL CANADA UPPER
TROUGH. ANOTHER SIGNIFICANT DRY AIRMASS WAS COMING IN BEHIND IT WITH
PRECIPITABLE WATER VALUES OF 0.5-0.75 INCHES ACROSS NORTH DAKOTA.
OVER THE NEXT 24 HOURS...THE TROUGHING OVER SOUTH CENTRAL CANADA IS
PROGGED TO DROP THROUGH THE FORECAST AREA. AS THE TROUGHING
APPROACHES...THE STREAM OF HIGHER PRECIPITABLE WATER VALUES JUST OFF
TO OUR WEST WILL MOVE INTO THE FORECAST AREA...BRINGING THE
POTENTIAL FOR PRECIPITATION. HOWEVER...FORCING MECHANISMS FOR
PRECIPITATION ARE A BIT PROBLEMATIC. FOR TONIGHT...THAT SHORTWAVE
TROUGH OVER NORTHERN MN IS PROGGED TO PROGRESS TOWARDS LAKE
SUPERIOR...WHILE THE SHORTWAVE TROUGH OVER IOWA HEADS DOWN INTO
MISSOURI AND SOUTHERN ILLINOIS. THUS...THESE SHORTWAVES SPLIT AROUND
THE REGION. MODEL QPF PROGS REFLECT THIS WELL. PERHAPS SOME SHOWERS
TRAILING SOUTH OF THE NORTHERN MN SHORTWAVE...AIDED BY DAYTIME
HEATING...WILL MAKE IT INTO NORTHWEST SECTIONS OF THE FORECAST AREA.
THIS IS EVIDENT ON CURRENT RADAR IMAGERY. THUS...HAVE MAINTAINED
SOME LOW PRECIPITATION CHANCES.
HEADING INTO MONDAY...PRECIPITATION CHANCES LOOK A LITTLE
BETTER...PRIMARILY ACROSS WISCONSIN AS THE MAIN TROUGHING COMES
THROUGH AT PEAK HEATING. ITS INTERESTING TO NOTE THAT THE SURFACE
COLD FRONT SHOULD COME THROUGH TONIGHT...BUT THE MOISTURE REALLY
DOESNT GET SCOURED OUT UNTIL THE MAIN TROUGHING MOVES IN. WITH
GOOD MODEL AGREEMENT FOR SHOWERS AND STORMS TO FIRE ACROSS
WISCONSIN IN THE LATE MORNING AND AFTERNOON...HAVE KEPT
PRECIPITATION CHANCES UP IN THE 60-70 RANGE. ONE THING WE WILL
HAVE TO WATCH IS SOME OF THE 12Z HIRES MODELS...ARW/NMM/SPCWRF-
NMM...SUGGEST PRECIPITATION COULD INITIATE JUST EAST OF THE
FORECAST AREA AND STAY TO THE EAST. WEST OF THE MS RIVER...CLOUDS
THAT MOVE IN TONIGHT ARE LIKELY TO CLEAR AS THE LOWER PRECIPITABLE
WATER VALUES ADVECT IN.
NOT ANTICIPATING ANYTHING SEVERE WITH THE STORMS ON MONDAY. ALTHOUGH
EQUILIBRIUM LEVELS ARE UP NEAR 30000 FT...CAPE PROFILE OVERALL IS
QUITE SKINNY. 0-6KM SHEAR IS LESS THAN 25 KT AND WARM CLOUD DEPTHS
ARE AROUND 3500 M. IF ANYTHING...WE WILL HAVE A COUPLE OF HEAVY RAIN
PRODUCERS.
INCREASING CLOUDS AND HIGHER PRECIPITABLE WATER TONIGHT SHOULD
RESULT IN A WARMER NIGHT TONIGHT. COOLEST SPOT LIKELY TO BE IN
CENTRAL WI WHERE CLOUDS/MOISTURE ARRIVE LAST. CLOUDS WILL BE A BIT
OF AN ISSUE ON MONDAY FROM WARMING...BUT ENOUGH SUN SHOULD FILTER
THROUGH PLUS CLEARING WEST OF MS RIVER LATER IN THE DAY TO ALLOW FOR
HIGHS IN THE 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
STRONG DRYING AND SUBSIDENCE ARE ON TRACK TO COME INTO THE FORECAST
AREA MONDAY EVENING...PUSHING ANY LINGERING PRECIPITATION QUICKLY
OFF TO THE EAST AND CAUSING SKIES TO CLEAR OUT. PRECIPITABLE WATER
VALUES FALLING TO 0.5-0.75 INCHES BY 12Z TUESDAY WOULD BE FAVORABLE
FOR A GOOD RADIATIONAL COOLING NIGHT...BUT A PERSISTENT NORTHWEST
BREEZE SHOULD HELP A BIT FROM ALLOWING TEMPERATURES TO COMPLETELY
TANK.
TUESDAY THROUGH WEDNESDAY FEATURES GRADUALLY RISING 500MB HEIGHTS AS
UPPER TROUGHING DEVELOPS OVER THE PACIFIC NORTHWEST...PUSHING THE
UPPER RIDGING THERE EASTWARD AND THE NEW TROUGHING OVER THE FORECAST
AREA EASTWARD. SUBSIDENCE FROM THESE RISING 500MB HEIGHTS SHOULD
HELP TO KEEP THE FORECAST AREA DRY. HOWEVER...LATE WEDNESDAY...BOTH
THE 10.12Z GFS AND NAM DEPICT SOME LIGHT QPF MOSTLY NORTH OF I-90.
10.12Z ECMWF HAS SOME ISOLATED LIGHT QPF...MOSTLY NORTH OF I-90.
10.12Z CANADIAN ALSO DEPICTS SOME LIGHT QPF BUT SOUTH OF I-90. THIS
QPF IS A RESULT OF A WARM ADVECTION PATTERN DEVELOPING...WITH
ISENTROPIC LIFT/800-700MB MOISTURE TRANSPORT INITIATING PRECIPITABLE
BELOW THE 500MB SUBSIDENCE. CONCERNED THE GFS/NAM MAY BE OVERLY
WET...ESPECIALLY THE GFS...BUT WITH THE SIGNAL THERE HAVE INCLUDED A
MENTION OF SPRINKLES ALONG/NORTH OF I-90. TEMPERATURES TUESDAY
SHOULD BOUNCE WELL INTO THE 70S...FOLLOWED BY GOOD RADIATIONAL
COOLING AT NIGHT AS A SURFACE RIDGE SETTLES IN. COULD SEE SOME
VALLEY/RADIATIONAL FOG EARLY WEDNESDAY MORNING AS WELL. SLIGHTLY
WARMER 850MB TEMPS ON WEDNESDAY COMBINED WITH MORNING SUN SHOULD
HELP GIVE A COUPLE DEGREE BOOST TO HIGHS COMPARED TO TUESDAY.
IN THE EXTENDED RANGE...GOOD MODEL AGREEMENT EXISTS OF THE PACIFIC
NORTHWEST TROUGH LIFTING OUT AND TRACKING EAST...ALLOWING THE UPPER
RIDGE DOWNSTREAM EVENTUALLY TO MOVE OVER THE FORECAST AREA FOR THE
WEEKEND. THIS 500MB FLOW PATTERN SUGGESTS PERSISTENT WARM ADVECTION.
09.12Z/10.00Z ECMWF AND 10.12Z GFS IN FACT SUGGEST A BRIEF SURGE OF
HEAT TO COME INTO THE AREA ON SUNDAY. HOWEVER...THE NEW 10.12Z HAS
COMPLETELY WENT AWAY FROM THIS...DUE TO A SHORTWAVE TROUGH DIGGING
SOUTH THROUGH THE PLAINS WHICH BLOCKS THE HEAT FROM ARRIVING ON
SUNDAY. MOST DAYS WE SHOULD SEE HIGHS IN THE UPPER 70S TO PERHAPS AT
MOST MID 80S. ON THE PRECIPITATION SIDE OF THINGS...ITS POSSIBLE
THAT MID-LEVEL SHOWER/SPRINKLE STUFF FROM WEDNESDAY AFTERNOON
PERSISTS THROUGH FRIDAY. THE LOCATION LOOKS TO SHIFT TO MOSTLY WEST
OF THE MS RIVER AND MAY HAVE A FEW MORE SHOWERS WITH IT.
THEREFORE...DO HAVE SOME 20-30 PERCENT CHANCES. FRIDAY NIGHT THROUGH
THE WEEKEND IS NOW UP IN THE AIR AFTER THE 10.12Z ECMWF CAME IN.
PREVIOUSLY IT APPEARED A BETTER SHOT FOR SHOWERS AND STORMS WOULD
COME FRIDAY NIGHT AND SATURDAY AHEAD OF THE HEAT SURGE...AND AGAIN
LATE SUNDAY AS THE PACIFIC NORTHWEST TROUGH APPROACHED. HOWEVER...
THE NEW ECMWF HAS THE ENTIRE REGION UNDER HIGH PRESSURE AND DRY
CONDITIONS. HAVE SPLIT THE DIFFERENCE FOR NOW WHICH RESULTS IN 20-40
PERCENT CHANCES...MAYBE A 50 THERE ON SUNDAY. IF THE ECMWF IS RIGHT
WITH THIS SHORTWAVE DIVING THROUGH THE PLAINS...THE WEEKEND WILL
NEED TO BE DRIED OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1207 AM CDT MON AUG 11 2014
SHORT WAVE ENERGY MOVING INTO ONTARIO PROVIDENCE WILL DRIVE SURFACE
COLD FRONT ACROSS AREA TODAY. TIMING FOR ANY INSTABILITY ALONG FRONT
WILL NOT FAVOR MUCH IN THE WAY OF RAIN THREATS AT EITHER TAF SITE SO
MAIN FOCUS IS POST-FRONTAL MVFR CEILINGS THAT WILL ADVECT IN LATER
TODAY. WILL HOLD THOSE IN A FEW HOURS ALONG WITH INCREASING WINDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA/WELVAERT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1124 PM CDT SUN AUG 10 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE STRETCHING FROM THE WESTERN GREAT LAKES TO NORTHEAST
NORTH AMERICA WHILE A COLD FRONT IS DROPPING SOUTHEAST OVER THE
NORTHERN GREAT PLAINS. A WEAK AREA OF LOW PRESSURE IS SPINNING OVER
CENTRAL MINNESOTA AHEAD OF THE FRONT...AND COMBINED WITH WEAK
SHORTWAVE ENERGY...IS PRODUCING SHOWERS FROM JUST WEST OF DULUTH TO
SOUTHWEST MINNESOTA. OTHER SPOTTIER SHOWERS ARE POPPING UP IN THE
MOISTURE RETURN OVER SOUTHERN AND CENTRAL LAKE MICHIGAN. MOST OF
THE MESO MODELS KEEP THESE LIGHT SPOTTY SHOWERS OR SPRINKLES
OFFSHORE OVER THE LAKE. BUT AS THE FRONT MOVES INTO THE REGION LATE
TONIGHT AND MONDAY...TIMING OF SHOWERS AND THUNDERSTORMS IS THE MAIN
FORECAST CONCERN.
TONIGHT...A SHORTWAVE TROUGH DROPPING SOUTHEAST OUT OF SOUTH-CENTRAL
CANADA WILL PUSH A COOL FRONT INTO NORTHWEST WISCONSIN LATE. AHEAD
OF THIS FRONT...LOW AND MID-LEVEL WINDS WILL SWING TO THE SOUTH AND
ADVECT MOISTURE FROM ILLINOIS AND INDIANA. A FEW SHOWERS FROM THIS
MOISTURE ARE PROJECTED TO REMAIN OVER THE LAKE. AMPLE CLOUD COVER
SHOULD ALSO ARRIVE WITH THE FRONT AS A WEAK AREA OF LOW PRESSURE
MOVES INTO CENTRAL WISCONSIN LATE. PROGGED SOUNDINGS INDICATE A
MID-LEVEL DRY WEDGE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN ERODING
LATE TONIGHT WHEN A MID-LEVEL THETAE AXIS MOVES INTO THAT PART OF
THE STATE. WILL RAMP UP PRECIP CHANCES AFTER 09Z WHEN THE COLUMN
BECOMES MORE SATURATED AND FORCING MARGINALLY INCREASES.
OTHERWISE...SLOWED DOWN THE CHANCE OF PRECIP THIS EVENING DUE TO THE
PRESENCE OF DRY AIR. LOW TEMPS SHOULD BE SEVERAL DEGREES WARMER DUE
TO THE INCREASING CLOUD COVER...AND WENT WITH TEMPS RANGING FROM
THE UPPER 50S NORTH OT LOWER 60S SOUTH.
MONDAY...THE SHORTWAVE AND COLD FRONT WILL GRADUALLY MOVE ACROSS
WISCONSIN. WITH DAYTIME HEATING...THE SREF INCREASES PRECIP CHANCES
DRAMATICALLY IN THE 15Z-18Z PERIOD OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...AND THEN SPREAD THE HIGHER PRECIP CHANCES INTO NORTHEAST
WISCONSIN AFTER MIDDAY. THIS LOOKS REASONABLE. TOUGH TO GET AN
ESTIMATE ON POTENTIAL INSTABILITY SINCE PROGGED SOUNDINGS LOOK
CONVECTIVELY MODIFIED...BUT A ROUGH ESTIMATE IS BETWEEN 500-1000
J/KG OF ML CAPE. BUT 0-6KM BULK SHEARS ARE ONLY AROUND 25 KTS AND
THINK FORCING IS TOO WEAK TO GENERATE MUCH OF A SEVERE THREAT. A
FEW STORMS COULD PRODUCE GUSTY WINDS TO 40-50 MPH AND SMALL HAIL.
MOSTLY CLOUDY AND MORE HUMID WITH HIGHS NEAR 70 NORTH TO AROUND 80
SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
RATHER STABLE MEAN LONGWAVE PATTERN FOR MOST OF THE EXTENDED WITH
NOTABLE TROUGHS SITUATED ON BOTH COASTS AND RIDGE OVER THE
INTER-MOUNTAIN WEST EXTENDING INTO CANADA. THE WESTERN GREAT LAKES
WILL REMAIN UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE BENEATH
NORTHWESTERLY FLOW ALOFT. PATTERN OFFERS LITTLE OPPORTUNITY FOR
SUBSTANTIAL RAINFALL FOR MOST OF THE WORK WEEK. SEASONABLY WARM
TEMPERATURES WITH COMFORTABLE DAYTIME HUMIDITIES...AND COOL NIGHTS
WILL BE THE RULE.
EARLY IN THE EXTENDED...DEEPENING UPPER TROUGH OVER THE GREAT
LAKES REGION MONDAY NIGHT WILL CONTINUE TO SWING EAST DURING THE
DAY ON TUESDAY. IN GENERAL...THE MODELS IN FAIRLY GOOD AGREEMENT
ON OVERALL TIMING OF BACK EDGE OF BROKEN BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS MONDAY EVENING. USING A BLENDED MODEL QPF
SUGGESTS THAT PRECIPITATION SHOULD BE EAST OF THE FORECAST AREA BY
06Z TUESDAY.
IN THE WAKE OF THE DEPARTING SURFACE LOW SITUATED NEAR LAKE HURON
TUESDAY MORNING...EXPECT FAIRLY DECENT NORTHERLY BOUNDARY LAYER
FLOW TO PERSIST AT LEAST FOR THE FIRST HALF OF THE DAY OVER THE
FORECAST AREA. GRADIENT SHOULD RELAX DURING THE AFTERNOON WITH
DIMINISHING WIND AND CLEARING SKIES. WITH THE CLOUDY START...COLD
ADVECTION...AND CORE OF COOLEST 850 TEMPS IN THE 8 TO 10 DEGREE
CELSIUS RANGE OVER THE AREA...DAYTIME HIGHS WILL BE THE COOLEST OF
THE WEEK...MAINLY IN THE LOW TO MID 70S.
DAYTIME HIGHS SHOULD MODERATE QUICKLY WEDNESDAY WITH READINGS
AROUND NORMAL FOR MIDDLE OF AUGUST. WEAK COLD FRONT DROPPING SOUTH
DURING THE DAY ON WEDNESDAY MAY BRING A FEW MORE CLOUDS AND
PERHAPS A SPRINKLE SOMETIME DURING THE DAY. DO NOT EXPECT MUCH
MORE THAN THAT GIVEN PALTRY MOISTURE AND FORCING.
HIGH PRESSURE REMAINS IN CONTROL THURSDAY AND FRIDAY WITH NEAR
NORMAL TEMPERATURES.
LATEST GUIDANCE WOULD ALSO SUGGEST SATURDAY WILL REMAIN DRY WITH
HINTS OF A CONFLUENT UPPER-LEVEL FLOW AND SURFACE RIDGE AXIS
PERSISTING OVER THE AREA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1123 PM CDT SUN AUG 10 2014
VFR MID TO HIGH LEVEL CLOUDS AHEAD OF A WEAK COLD
FRONT WILL CONTINUE TO THICKEN OVERNIGHT. SCATTERED SHOWERS WITH
AREAS OF MVFR CIGS WILL SPREAD OVER THE NORTHWEST HALF OF THE
STATE LATE OVERNIGHT...AND THEN OVER THE REST OF THE AREA ON
MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
545 AM MST MON AUG 11 2014
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES
FOR MONSOON RAIN THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR
RAIN WILL BE TUESDAY AND WEDNESDAY AS A SURGE OF MONSOONAL MOISTURE
MOVES THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL
LEVELS WITH THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY
CLOUDY SKIES SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER
CONDITIONS EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK
OVER THE REGION.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG
DOWNBURST WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND
LOCALIZED FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SCT-BKN MID LEVEL CLOUD DECKS AOA 12K FT...AND WINDS REMAINING
GENERALLY EASTERLY THROUGH THE DAY. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING OVER HIGHER TERRAIN NORTH/EAST/SOUTH OF
TERMINALS AFTER 19Z...A FEW STORMS AFFECTING TERMINALS AFTER 00Z
TUESDAY AS SOUTHEASTERLY STEERING FLOW WILL HELP MOVE STORMS INTO
LOWER DESERTS. EXPECT LOCAL CIGS DOWN TO 8KFT WITH STORMS THAT
APPROACH TERMINALS...ALONG WITH POTENTIAL FOR VISIBILITY REDUCTIONS
DOWN TO 1SM OR LESS IN AREAS OF BLOWING DUST AND 40-45KT OUTFLOW
WINDS. STORM ACTIVITY EXPECTED TO PERSIST UNTIL AROUND 06Z TUESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT-BKN MID LEVEL CLOUDS GENERALLY AOA 12K PERSISTING THROUGHOUT THE
DAY...WITH ISOLATED THUNDERSTORMS POSSIBLE DURING THE LATE AFTERNOON
AND EVENING...FORMING EAST-SOUTHEAST OF KNYL/YUMA. NOT OUT OF THE
QUESTION FOR OUTFLOW WINDS FROM DISTANT STORMS TO CAUSE WIND SHIFTS
AT TERMINALS LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHTER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
340 AM MST MON AUG 11 2014
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES
FOR MONSOON RAIN THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR
RAIN WILL BE TUESDAY AND WEDNESDAY AS A SURGE OF MONSOONAL MOISTURE
MOVES THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL
LEVELS WITH THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY
CLOUDY SKIES SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER
CONDITIONS EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK
OVER THE REGION.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG DOWNBURST
WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND LOCALIZED
FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
CONSIDERABLE MID LEVEL DEBRIS CLOUDS NOW MOVING INTO THE CENTRAL
DESERTS WITH CIGS AOA 10K FT EXPECTED FOR THIS EVENING INTO MONDAY
MORNING. ALSO...GUSTY EASTERLY OUTFLOW WINDS HAVE MOVED INTO THE
DESERTS AND WINDS HAVE SHIFTED TO THE EAST AT ALL TAF SITES...WITH
GUSTS TO NEAR 30MPH SEEN AT KIWA. MAY SEE WINDS AOA 15KT AT TIMES AT
BOTH KPHX AND KSDL THRU 04-05Z THEN TAPERING OFF AND REMAINING
EASTERLY THRU DAY ON MONDAY. OUTFLOWS SPURRED ISOLATED STORMS NEAR
KIWA...BUT EXPECT THESE STORMS TO DISSIPATE AND LIKELY WILL NOT
AFFECT EITHER KPHX OR KSDL. AT LEAST...CONFIDENCE LOW ATTM THAT
STORMS WILL MOVE INTO KPHX.
MAY SEE A BETTER CHANCE FOR THUNDERSTORMS TO AFFECT THE GREATER
PHOENIX AREA TAF SITES MONDAY EVENING AS ATMOSPHERE BECOMES MORE
MOIST AND UNSTABLE...AND SELY STEERING WINDS ALOFT INCREASE.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES WILL PREVAIL THROUGH AT LEAST THIS EVENING...WITH
A FAIRLY DECENT CHANCE OF CIGS AOA 10K FT SPREADING INTO THE REGION
BY SUNRISE MONDAY. ALTHOUGH MUCH LOWER CONFIDENCE...OUTFLOW WINDS
FROM SWRN ARIZONA MAY CAUSE WIND SHIFTS TO A SELY DIRECTION LATER
TONIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MO/CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1100 AM EDT MON AUG 11 2014
...FORECAST AREA IS SPLIT BETWEEN WET CONDITIONS NORTH AND DRIER
CONDITIONS SOUTH...
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NEXT SIGNIFICANT
AMPLIFICATION TO THE MID/UPPER LEVEL PATTERN OVER THE EASTERN CONUS
QUICKLY EVOLVING SOUTHWARD THROUGH THE UPPER MIDWEST. AMPLIFIED
UPSTREAM RIDGING IS SEEN OVER MUCH OF THE INTER-MOUNTAIN WEST. THIS
PATTERN HAS BEEN SO PERSISTENT THIS SUMMER WITH THE WESTERN RIDGE
AND EASTERN TROUGH...AND IT DOES NOT LOOK TO BREAK ANYTIME THIS
WEEK. CLOSER TO HOME...OUR LOCAL AREA REMAINS UNDER THE INFLUENCE OF
WEAK WEST-EAST ORIENTED UPPER RIDGING. A UPPER LEVEL TUTT FEATURE IS
SEEN CLEARLY ON WV IMAGERY THIS MORNING UNDER-CUTTING THE UPPER
RIDGE...MIGRATING WESTWARD THROUGH THE FLORIDA STRAITS AND EMERGING
INTO THE SE GULF OF MEXICO. THIS FEATURE IS MOST DEFINED IN THE
400-200MB LAYER AND IS HAVING THE EFFECT OF ENTRAINING DRIER AIR
FROM THE EAST ALOFT INTO ITS CIRCULATION AND OVER THE SOUTHERN FL
PENINSULA.
11/12Z KTBW SOUNDING PROFILE HAS CHANGED LITTLE IN THE PAST 24
HOURS...STILL SHOWS ABOVE CLIMO PW...BUT NOT UNUSUAL VALUES FOR LATE
SUMMER. H5 TEMPS REMAIN AROUND -6C...WHICH IS FAIRLY WARM...AND
LAPSE RATES THROUGH MUCH OF THE COLUMN ARE NOT FAR FROM MOIST
ADIABATIC. HOWEVER...NO SIGNIFICANT LAYERS OF LOW THETAE ARE NOTED
TO HAVE A NEGATIVE INFLUENCE ON CONVECTIVE COLUMNS. FOR ANOTHER
DAY...CONVECTION SHOULD HAVE LITTLE TROUBLE GROWING IN THIS
ENVIRONMENT...HOWEVER STRONG UPDRAFT AND THE THREAT OF SEVERE
WEATHER IS QUITE LOW. HEADING FURTHER SOUTH TOWARD THE MIAMI KMFL
MORNING SOUNDING...WE FIND A DRIER PROFILE...ESPECIALLY IN THE
MIDDLE/UPPER LEVELS...BUT EVEN SOMEWHAT BELOW 500MB.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE FAR
SOUTHERN FL PENINSULA WITH OUR FORECAST AREA RESIDING BETWEEN
THIS AXIS AND A QUASI-STATIONARY FRONTAL BOUNDARY NEAR/JUST NORTH OF
THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW IS FRONT THE SW. AS
THE LOW LEVEL SW FLOW ROUNDING THE RIDGE AXIS MEETS THE MORE
WESTERLY FLOW JUST AHEAD OF THE FRONT WE HAVE SET UP A CONVERGENCE
BAND ACROSS THE NE GULF OF MEXICO. THIS LOW LEVEL FOCUS FOR ASCENT
IS HELPING TO FUEL SCT/NMRS SHOWERS AND ISOLATED STORMS MIGRATING
ONSHORE FROM ROUGHLY THE I-4 CORRIDOR NORTHWARD. THE ENSEMBLE NWP
GUIDANCE SUITE HAS BEEN DOING A FAIRLY GOOD JOB WITH THIS PATTERN...
ALTHOUGH THE INITIATION OF PRECIP HAS GENERALLY BEEN ABOUT 3-4 HOURS
TOO EARLY IN THE SIMULATION THE PAST COUPLE OF MORNINGS COMPARED TO
REALITY.
REST OF TODAY AND TONIGHT...
NUMEROUS SHOWERS/STORMS/CLOUDS FROM TAMPA BAY NORTHWARD ARE LIKELY
TO PREVENT MUCH OF A SEA BREEZE ALONG THE NATURE COAST THIS
AFTERNOON. WITHOUT THE SEA-BREEZE TO DISSIPATE THE CONVERGENCE ZONE
OVER THE NORTHERN COASTAL WATERS...WE ARE LIKELY TO SEE THE SHOWERS
CONTINUE MOVING ASHORE INTO THE AFTERNOON. LIKELY POPS FROM THE I-4
CORRIDOR NORTHWARD WILL REMAIN IN THE GRIDS FOR SEVERAL MORE HOURS
AT LEAST...WITH RAIN CHANCES QUICKLY DECREASING TO THE SOUTH OF
HILLSBOROUGH/POLK COUNTIES. DO EXPECT TO SEE SOME LATER AFTERNOON
STORMS OVER THE INLAND PORTIONS OF THE SOUTHERN FORECAST
AREA...HOWEVER COVERAGE SHOULD NOT BE GREAT. CLIMO COVERAGE FOR
THESE REGIONS DURING SW FLOW IN THE SUMMER IS (40-50%). ADD IN THE
DRIER AIR ALOFT AND ~30% LOOKS MORE ACCURATE.
WILL ALSO SEE A BIG DIFFERENCE IN TEMPERATURE FROM NORTH TO SOUTH.
FREQUENT SHOWERS/COOLER OUTFLOW/CLOUDS WILL HOLD TEMPS IN THE 80S
NORTH (PERHAPS UPPER 70S FOR SOME LOCATIONS)...WHILE SOUTH OF TAMPA
BAY...LOWER TO MIDDLE 90S WILL BE COMMON).
LIKELY TO SEE THE SHOWERS DECREASE IN COVERAGE (EVEN OVER THE
NORTHERN HALF OF THE AREA AS WE HEAD LATE INTO THE DAY AND EVENING.
WILL NOT COMPLETELY REMOVE RAIN CHANCES...BUT THE CONVERGENCE SHOULD
BE AT A MINIMUM THIS EVENING INTO THE FIRST HALF OF THE OVERNIGHT.
TUESDAY...
THERE ARE SOME INDICATIONS THAT THE SUBTROPICAL RIDGE AXIS WILL
MIGRATE A BIT TO THE NORTH (50-75 MILES) BY TUESDAY MORNING. WHILE
THIS MAY NOT SEEM LIKE MUCH...THIS MIGHT ALSO DISPLACE THE
CONVERGENCE BAND TOMORROW TO THE NORTH AS WELL. THERE IS SOME
INDICATION OF THIS IN THE LATEST SREF ENSEMBLE OUTPUT. THINKING THE
AFTERNOON FORECAST PACKAGE WILL FOLLOW THIS PHILOSOPHY AND HOLD THE
BETTER RAIN CHANCES TUESDAY TO THE NORTH OF TAMPA BAY (PERHAPS
HERNANDO/SUMTER COUNTIES NORTHWARD). THE PATTERN SEEN TODAY OVER THE
SOUTHERN ZONES WOULD THEN BE EXPANDED NORTHWARD THROUGH THE I-4
CORRIDOR...WITH A MAINLY DRY MORNING FOR ALL...FOLLOWED BY SCT
INLAND DEVELOPMENT FOR THE AFTERNOON. ALL THIS WILL DEPEND ON THE
RIDGE AXIS ACTUAL MOVING NORTH AS THE CURRENT GFS AND ECMWF SHOW.
12Z GUIDANCE PACKAGE WILL BE ARRIVING SHORTLY AND WILL SEE IF THIS
NWP TREND CONTINUES BEFORE MAKING ANY FINAL DECISIONS REGARDING THE
TUESDAY FORECAST. ENJOY THE REST OF YOUR MONDAY!
&&
&&
.AVIATION...
MAIN AVIATION CONCERNS THROUGH EARLY AFTERNOON WILL BE THE NORTHERN
TERMINALS OF KTPA/KPIE/KLAL WHERE PERIOD SHOWERS/STORMS ARE EXPECTED
WITH ASSOCIATED BRIEF PERIODS OF CIG/VIS RESTRICTION IN RAIN.
FURTHER SOUTH...CHANCES FOR ANY SHOWERS AND RESTRICTIONS DECREASES
QUICKLY...AND FEEL COVERAGE WILL BE ISOLATED ENOUGH TO HAVE LEFT OUT
MENTION IN KPGD/KFMY/KRSW. LOOKING FOR A LET UP IN THE SHOWERS
ACROSS THE NORTH LATER TODAY. ANOTHER ROUND OF SHOWERS SHOULD
DEVELOP LATE TONIGHT INTO TUESDAY MORNING OVER THE NATURE COAST WITH
KTPA/KPIE/KLAL RESIDING ON THE SOUTHERN EDGE OF THIS THREAT AREA.
AWAY FROM THE RAIN ASSOCIATED WITH ANY STORMS...VFR CONDITIONS WILL
PREVAIL.
&&
.MARINE...
INTERACTION BETWEEN A FRONTAL BOUNDARY OVER NORTHERN FLORIDA AND THE
SUBTROPICAL RIDGE AXIS ACROSS SOUTHERN FLORIDA WILL KEEP WEST TO
SOUTHWEST FLOW IN PLACE FOR THE NEXT SEVERAL DAYS. THE FLOW WILL BE
A BIT STRONGER TODAY...AROUND 15 KNOTS FOR THE OFFSHORE WATERS
ADJACENT TO THE NATURE COAST. NO HEADLINES ARE EXPECTED OTHERWISE
AND SEAS WILL REMAIN 3 FEET OR LESS. SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED THIS MORNING OVER THE GULF AND NEAR SHORE
WATERS...ESPECIALLY NORTH OF TAMPA BAY. THIS ACTIVITY WILL CONTINUE
THROUGHOUT THE WEEK. MAIN HAZARDS WILL BE SCATTERED
THUNDERSTORMS...DANGEROUS LIGHTNING...AND LOCALIZED GUSTY WINDS IN
AND NEAR THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 78 92 79 / 60 20 30 30
FMY 94 77 93 77 / 20 10 20 20
GIF 89 76 93 76 / 60 10 30 10
SRQ 91 78 91 78 / 40 20 20 20
BKV 87 75 91 73 / 70 30 40 30
SPG 88 80 91 80 / 60 20 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...WYNN
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1000 AM CDT Mon Aug 11 2014
.UPDATE...
ISSUED AT 1000 AM CDT MON AUG 11 2014
Morning surface analysis shows low pressure centered over
north-central Indiana, with bulk of associated precip well to the
E/NE of the KILX CWA over northern Indiana/southern Michigan.
Further west in Illinois, only isolated showers persist along the
I-57 corridor. As low moves further away and short-wave subsidence
develops behind departing upper wave, think conditions will be
mostly dry for the balance of the morning into the early
afternoon. Cold front currently across central Iowa will push
eastward later today, perhaps enhancing precip chances by mid to
late afternoon. While front will be encountering a moist airmass
with CAPE vales projected to be around 1500J/kg, poor convergence
along the boundary and extremely weak bulk shear will keep
convective development to a minimum. Both the 12z NAM and the
latest HRRR show only widely scattered showers/thunder developing
along the front across the Illinois River Valley after 1 PM, then
spreading eastward to the I-55 corridor by 4 to 5 PM. Will
therefore only carry 20-30 PoPs today into the early evening,
before ending precip chances entirely after midnight. Made a few
adjustments to PoPs and sky cover today, but temps appear to be
right on track so far.
&&
.SHORT TERM...(This afternoon through Tuesday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Patchy showers, with an occasional lightning strike evident,
continue to push slowly east across west-central Illinois early this
morning. These showers are ahead of an impulse that is quite
noticeable on water vapor imagery. A more widespread area of
showers/storms lies across northeast Illinois, associated with some
low-mid level convergence and weak WAA ahead of the above mentioned
impulse. Meanwhile, a cold front extends southwest into the upper
Midwest from northern Ontario. This front is being driven by a
couple upper level waves, and will eventually clear the forecast
area to the east by this evening.
High-resolution models suggest the west-central Illinois showers
should continue east for a time, but eventually weaken. Have my
doubts that this will occur as progged, as this feature will
eventually have diurnal instability to work with. Do not expect
severe storms today given weak shear profiles (bulk shear generally
20 kts or below), but peak diurnal instability should approach 1500
j/kg over most of the forecast area. This instability and the
available forcing should be able to produce scattered thunderstorms
across most of the forecast area today. The best coverage is expected
in the east, where the forcing from the west-central Illinois wave
and peak heating will co-exist for the longest period of time.
However, can`t rule out additional development until early evening
when the surface cold front and main upper wave pass east of the
area. Lingering cloud cover, as well as shower/storm threat, should
keep high temperatures today similar to the past two, generally in
the lower 80s.
&&
.LONG TERM...(Tuesday night through Sunday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Strong upper level trof will be over the Ohio river valley Tue as
surface low pressure ejects ne to along the Quebec/Ontario province
line by sunset Tuesday. A few showers could occur over ne CWA Tue
while most of central IL should be dry Tue as skies become mostly
sunny Tue afternoon. Northwest breezes to bring in cooler and less
humid air as dewpoints slip into the upper 50s and lower 60s by days
end. Highs 75-80F on Tuesday with warmest readings by Lawrenceville.
Skies clear and nw winds diminish light by overnight Tuesday night
with cooler lows in the mid 50s. Upper level trof pulling away from
IL on Wed while 1021 mb Canadian high pressure settling into the
Midwest and keeps cooler and drier air in place through Thu night.
Highs Wed mostly in the upper 70s with lows Wed night in the upper
50s. Highs Thu in the lower 80s and dewpoints easing up into the
lower 60s Thu afternoon as surface ridge drifts east across IL.
Extended models diverge late this week and the models overall have
trended slower with arrival of next weather system late this week.
Most models are now drier on Friday over central/se IL with surface
high pressure ridge drifting slowly east into IN/OH/KY. Have lowered
pops Friday with eastern IL staying dry Friday, and having 20-30%
chance by Friday afternoon over western areas. Stayed close to
AllBlend during the extended forecast this weekend into early next
week which brings chances of showers and thunderstorms across the
area Friday night and Saturday with an approaching warm front from
the southwest. Warmer and more humid air to return to IL this
weekend as dewpoints elevate into the upper 60s and lower 70s. Upper
level ridge over IL by Sunday and this appears to be the warmest day
with highs in the mid to upper 80s. Main storm track to shift north
of central IL early next week and just have slight chances of
showers and thunderstorms Sunday-Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 654 AM CDT MON AUG 11 2014
MVFR/IFR conditions across the central Illinois terminals to start
the day, with scattered showers and isolated thunderstorms in the
vicinity. Covered this precipitation with a few hour tempo for
showers at all locations. Then, a break is expected in the
precipitation, with conditions improving to VFR by mid-late
morning. A few showers/storms may return by late afternoon ahead
of a weak cold front, but coverage and timing certainty is too low
to go above a VCSH mention. Rain chances will end tonight, but
cigs/vsbys are likely to return to MVFR (or lower) behind the
front overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...BARNES
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1106 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 1102 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION TODAY INTO
TONIGHT AND AN UPPER LEVEL TROUGH WILL MOVE THROUGH TONIGHT INTO
TOMORROW. THESE TWO WILL CAUSE PERIODS OF SHOWERS AND
THUNDERSTORMS THROUGH TOMORROW. HIGH TEMPERATURES WILL RANGE FROM
THE MIDDLE 70S IN THE NORTH TO THE UPPER 70S NEAR THE OHIO RIVER.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE UPPER 60S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 730 AM EDT MON AUG 11 2014
SFC LOW PRESSURE WILL TRACK ACROSS NORTHEAST INDIANA THIS MORNING.
CYCLONIC FLOW AROUND THIS LOW LEVEL REFLECTION HAS ALLOWED
INCREASED LOW LEVEL MOISTURE TO BUILD NORTHWARD ACROSS NORTHERN
INDIANA THIS MORNING. THE COMBINATION OF CONVERGENT FLOW AND AN
UPSTREAM SHORT WAVE WORKING INTO NORTHWEST INDIANA THIS MORNING
WILL RESULT IN WIDESPREAD RAIN TO OVERSPREAD THE AREA THIS
MORNING...WITH GREATEST COVERAGE EXPECTED TO AFFECT KSBN THROUGH
EARLY AFTERNOON. SFC OR NEAR SFC BASED INSTABILITY OF AROUND 1000
J/KG IS EXPECTED TO DEVELOP LATER THIS MORNING AND SHOULD SUPPORT
AT LEAST SCATTERED THUNDER. ONLY CHANGE OF NOTE FOR THE 12Z TAFS
WAS TO MOVE UP TIMING OF THUNDER TO LATE MORNING/EARLY
AFTERNOON...ALTHOUGH GIVEN SETUP...REALLY CANNOT RULE OUT TS ANY
TIME OVER THE NEXT 6 TO 9 HOURS AND WILL NEED TO BE MONITORED. WITH
SFC REFLECTION MOVING ACROSS THE AREA WINDS WILL BE RELATIVELY
NIGHT...EVENTUALLY FAVORING NORTH-NORTHWEST LATER THIS AFTERNOON
AS IT DEPARTS TO THE EAST. DID HOLD ONTO MVFR CONDITIONS TONIGHT
WITH MOISTURE LINGERING ACROSS THE AREA IN ADVANCE OF NEXT SHORT
WAVE...BUT MAY EVENTUALLY NEED TO ASSESS POTENTIAL FOR MORE
PESSIMISTIC CONDITIONS LATE TONIGHT IN FUTURE FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 4 PM CDT THIS AFTERNOON FOR INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 5 PM EDT THIS AFTERNOON FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
749 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 344 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL SHIFT NORTHEAST ACROSS THE REGION
TODAY. THIS COMBINED WITH AN UPPER LEVEL SYSTEM WILL CAUSE PERIODS
OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE AREA TODAY INTO
TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM ALLOWING
FOR DRY WEATHER WEDNESDAY INTO THE END OF THE WORK WEEK. HIGHS
TODAY WILL IN THE MID TO UPPER 70S WITH OVERNIGHT LOWS IN THE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 730 AM EDT MON AUG 11 2014
SFC LOW PRESSURE WILL TRACK ACROSS NORTHEAST INDIANA THIS MORNING.
CYCLONIC FLOW AROUND THIS LOW LEVEL REFLECTION HAS ALLOWED
INCREASED LOW LEVEL MOISTURE TO BUILD NORTHWARD ACROSS NORTHERN
INDIANA THIS MORNING. THE COMBINATION OF CONVERGENT FLOW AND AN
UPSTREAM SHORT WAVE WORKING INTO NORTHWEST INDIANA THIS MORNING
WILL RESULT IN WIDESPREAD RAIN TO OVERSPREAD THE AREA THIS
MORNING...WITH GREATEST COVERAGE EXPECTED TO AFFECT KSBN THROUGH
EARLY AFTERNOON. SFC OR NEAR SFC BASED INSTABILITY OF AROUND 1000
J/KG IS EXPECTED TO DEVELOP LATER THIS MORNING AND SHOULD SUPPORT
AT LEAST SCATTERED THUNDER. ONLY CHANGE OF NOTE FOR THE 12Z TAFS
WAS TO MOVE UP TIMING OF THUNDER TO LATE MORNING/EARLY
AFTERNOON...ALTHOUGH GIVEN SETUP...REALLY CANNOT RULE OUT TS ANY
TIME OVER THE NEXT 6 TO 9 HOURS AND WILL NEED TO BE MONITORED. WITH
SFC REFLECTION MOVING ACROSS THE AREA WINDS WILL BE RELATIVELY
NIGHT...EVENTUALLY FAVORING NORTH-NORTHWEST LATER THIS AFTERNOON
AS IT DEPARTS TO THE EAST. DID HOLD ONTO MVFR CONDITIONS TONIGHT
WITH MOISTURE LINGERING ACROSS THE AREA IN ADVANCE OF NEXT SHORT
WAVE...BUT MAY EVENTUALLY NEED TO ASSESS POTENTIAL FOR MORE
PESSIMISTIC CONDITIONS LATE TONIGHT IN FUTURE FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
529 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 526 AM MDT MON AUG 11 2014
ADDED MENTION OF PATCHY FOG TO NORTHERN PART OF CWA BASED ON
CURRENT OBS ALONG REPUBLICAN RIVER VALLEY. CURRENTLY NOT REALLY
CONFIDENT ON EXTENT OF FOG...SO KEPT COVERAGE/MENTION IN LINE WITH
LATEST SHORT RANGE GUIDANCE/OBS WITH DISSIPATION EXPECTED BY MID
MORNING WHEN DAYTIME HEATING WILL ERODE FOG.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 526 AM MDT MON AUG 11 2014
FOG HAS DEVELOPED OVER PORTIONS OF SW NEBRASKA...AND VIS BETWEEN 5
TO 7 SM WILL BE POSSIBLE AT TIME AT KMCK. I CANT COMPLETELY RULE
OUT VIS DROPPING LOWER THAN THIS...HOWEVER SHORT RANGE GUIDANCE
AND AREA OBS ARE NOT SUPPORTIVE OF LOWER CONDITIONS. VFR CONDITIONS
SHOULD PERSIST AT KGLD. WINDS WILL REMAIN LIGHT AROUND 5 KT
THROUGH THE TAF PERIOD WITH NORTHERLY WINDS EVENTUALLY SHIFTING TO
THE SOUTHEAST THIS EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1125 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM MONDAY...
THE LATEST VISIBLE IMAGERY SHOWS SOME GOOD LOW-LEVEL DRY AIR HAVING
WORKED ITS WAY ACROSS A LARGE SEGMENT OF CENTRAL NORTH CAROLINA
ESPECIALLY ALONG AND EAST OF ABOUT U.S. 1. PRECIPITATION HAS HAD A
HARD TIME MOVING EAST...AND TEMPERATURES HAVE WARMED NICELY TOWARD
KCTZ. THE RAP SEEMS TO HAVE BEEN TOO AGGRESSIVE IN MOVING THE 850MB
MOISTURE EAST AND IF THE LATEST RAP TRENDS AND VISIBLE IMAGES
CONTINUE...PEEKS OF SUN WILL BE PRESENT AT TIMES AT LEAST AS FAR
WEST AS U.S. 1. RADAR TRENDS ALSO SHOW DEEP CONVECTION DEVELOPING
ALONG THE NORTH CAROLINA SEA BREEZE SO STILL EXPECT SHOWERS TO
DEVELOP DURING THE AFTERNOON POSSIBLY MORE INSTABILITY DRIVEN AND
MOVING THEN TOWARD THE NORTHWEST IN THE LOW-LEVEL FLOW. HIGHEST
CHANCES FOR PRECIPITATION IN THE IMMEDIATE TRIAD.
TEMPERATURES REMAIN A CHALLENGE BUT THE LATEST FORECAST STILL SEEMS
TO HAVE A GOOD...BASIC HANDLE ON EXPECTED MAXIMUMS IN GENERAL.
RAISED MAXES TOWARD KCTZ AND NUDGED JUST SLIGHTLY LOWER TOWARD
KEXX...BUT LEFT THE REST INTACT FOR NOW ALTHOUGH MORE THIN SPOTS
COULD PROVIDE FOR WARMER READINGS SUCH AS TOWARD KFAY. LOWS TONIGHT
IN THE UPPER 60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR
PRECIPITATION IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD
INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 1125 AM MONDAY...
CLOUDS HAVE BEEN STRUGGLING TO LOWER EVEN IN THE TRIAD THIS MORNING
AS THE RAP SEEMS TO BE OVERDOING THE AMOUNT OF LOW-LEVEL REALLY
MOIST AIR. HIGHEST POTENTIAL FOR CONDITIONS THROUGH MUCH OF THE
AFTERNOON IS FOR VFR CONDITIONS WITH SCATTERED LOWER CLOUDS IN MVFR.
THE BETTER CHANCES FOR A PERIOD OF IFR CONDITIONS REMAINS TOWARD THE
TRIAD AND PARTICULARLY TOWARD KINT IN THE MORE MOIST AND MODESTLY
UPSLOPE FLOW. OUTSIDE OF THE IMMEDIATE TRIAD...SHOWERS SHOULD BECOME
SCATTERED-TO-NUMEROUS LATER THIS AFTERNOON WITH A THUNDERSTORM
POSSIBLE ESPECIALLY TOWARD KFAY. SUB-VFR CEILINGS ARE THEN LIKELY TO
RETURN TONIGHT.
OUTLOOK...LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...DJF/BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE CONTINUING TO
EXTEND SOUTH ACROSS THE CAROLINAS...WITH LIMITED PRESSURE RISES THIS
MORNING ALTHOUGH WITH A WEAK TROUGH NOTED IN THE HIGH OVER THE
WESTERN PIEDMONT AND FOOTHILLS COINCIDENT WITH THE LEADING EDGE OF
THE AREA OF MOSTLY LIGHT PRECIPITATION. AS THE 500MB RIDGE AXIS WAS
MOVING EAST AT 12Z...THE FLOW WAS WEAKLY DIFFLUENT ALOFT...FORECAST
BY THE RAP TO CONTINUE INTO THE AFTERNOON. THE 850MB FLOW WAS FROM
THE SOUTHEAST AND IN CONJUNCTION WITH WEAK ISENTROPIC LIFT NOTED BY
THE RAP ON THE 310K SURFACE THAT SEEMS TO INCREASE THIS MORNING TO A
MAXIMUM EARLY THIS AFTERNOON...GRADUALLY TAKING ON A SOUTHWEST-TO-
NORTHEAST ORIENTATION LATE IN THE DAY AND THIS EVENING AND
ESPECIALLY WEST OF U.S. 1 THEN. 850MB THETA-E ADVECTION GRADUALLY
EXTENDS EAST INTO THE COASTAL PLAIN DURING THE DAY THEN IS ACTUALLY
FORECAST BY THE RAP TO RETREAT WEST THIS EVENING.
RADAR TRENDS HAVE SHOWN A STEADY INCREASE IN LIGHT PRECIPITATION
JUST WEST OF THE TRIANGLE AND FAYETTEVILLE TO INCLUDE CERTAINLY THE
TRIAD...AND ANTICIPATE THIS TO CONTINUE FILLING IN SOME WITH
NUMEROUS PATCHES OF SHOWERS AND LIGHT RAIN. FOR MUCH OF THE DAY IN
MANY OF THE LOCATIONS WHERE CHANCES OF PRECIPITATION ARE HIGHER...
IT COULD BE A SITUATION OF HIGH POP AND LOW QPF. FARTHER
EAST...THERE WERE ACTUALLY BREAKS IN THE CLOUDS TOWARD KFAY AND
KCTZ...AND JUST EAST OF KIXA...ALL OF WHICH SHOULD MOSTLY FILL IN
WITH TIME. ON THE EDGES OF CENTRAL NORTH CAROLINA ESPECIALLY TO THE
EAST...THERE SHOULD BE AT LEAST A FEW GLIMPSES OF SUN WITH THE 850MB
THETA-E GRADIENT LOCATED THERE FOR THE AFTERNOON.
TEMPERATURES ARE AGAIN A CHALLENGE BUT THE LATEST FORECAST HAS A
BASIC PERSISTENCE FORECAST FROM HIGHS SUNDAY WHICH...BASED ON THE
LATEST VISIBLE SATELLITE IMAGE...SEEMS ON TRACK. TEMPERATURES SHOULD
STRUGGLE TO RISE IN THE TRIAD THOUGH SOME AREAS IN THE FAR EAST LIKE
KETC AND KCTZ MAY BE FORECAST TOO COOL. LOWS TONIGHT IN THE UPPER
60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR PRECIPITATION
IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. PRECIP HAS BEEN EXPANDING OVER THE FOOTHILLS THIS MORNING
AND WILL SLOWLY SPREAD EAST ACROSS THE TRIAD THROUGH MIDDAY. LOW
CLOUDS WILL CONTINUE TO BE FAVORED OVER WESTERN PORTIONS OF THE
AREA...WITH MVFR CEILINGS LIKELY LOWERING TO AT LEAST IFR AT
KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW FAR EAST THE SUB-
VFR CEILINGS WILL EXPAND TO THE EAST...SO CONFIDENCE IN MVFR OR IFR
CEILINGS AT KRDU IS LOWER. HOWEVER...THE MOST RECENT RAP AND HRRR
SHOW LESS STRATUS AT KRDU...KRWI AND KFAY...WITH CEILINGS HOVERING
AT HIGH END MVFR OR ABOVE. SHOWERS WILL ALSO BE POSSIBLE IN THE
VICINITY OF KFAY BY THIS AFTERNOON. SUB-VFR CEILINGS ARE THEN LIKELY
TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
743 AM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR HEAVY RAINFALL OVER ALREADY WET GROUND. A
FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA TODAY. A STRONG COLD
FRONT WILL CROSS THE AREA OVERNIGHT WEDNESDAY...BRINGING DRIER
CONDITIONS AND COOLER NIGHT-TIME TEMPERATURES INTO LATE WEEK.
SEASONABLE WEATHER IS EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...NO SIGNIFICANT CHANGES TO FORECAST REASONING
WITH THE DAYBREAK UPDATES. SEVERAL SIGNALS REMAIN IN PLACE FOR A
POTENTIAL OF LOCALIZED BUT SIGNIFICANT FLOODING. NESDIS RELEASED A
SATELLITE PRECIPITATION ESTIMATES MESSAGE FOR THE CHS AND ILM
WARNING AREAS FOR INGREDIENTS IN PLACE FOR POSSIBLE HEAVY RAIN
LATER THIS MORNING. LATEST RADAR TRENDS SHOW CELLS TEAMING UP
OFFSHORE IN WHAT APPEARS TO BE A SHARPENING AXIS OF LOW-LEVEL
CONVERGENCE. KLTX VAD WIND PROFILE SHOWS 25 KT EAST WIND FLOW OFF
THE BALMY ATLANTIC IN THE LOWEST FEW THOUSAND FEET INDUCING AN
INFERRED AND CORRESPONDING INCREASE IN 975-925 MOISTURE TRANSPORT
VECTORS...BUT AS YET RADAR ECHOS REMAIN OVER THE OUTER WATERS. THE
PREVIOUS EARLY MORNING DISCUSSION FOLLOWS.
A FLOOD WATCH IS POSTED FOR NE SC AND SE NC DUE TO THE POTENTIAL
ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS OVER SOGGY GROUND AND
EVEN STANDING WATER AREAS ACROSS OUR ZONES. SATELLITE SENSORS ARE
REGISTERING A POOL OF DEEP COLUMN MOISTURE IN EXCESS OF 2 INCH
PRECIPITABLE WATER VALUE...ACROSS MOST OF THE GULF STATES
EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS POOL WILL
WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE EASTERN
SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT DEEPEN
FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...EXCEPT FOR IFR CIGS AT KFLO...TERMINALS ARE VFR THIS
MORNING. SKIES ARE SCT TO CLEAR...BUT 11U-3.9U SATELLITE LOOPS
SHOW MID CLOUDS BEGINNING TO SPREAD BACK ACROSS THE TERMINALS.
ONLY ISOLATED VERY LIGHT SHOWERS ARE OCCURRING. RADAR LOOPS SHOW
SHOWERS MOVING/DEVELOPING WNW...WHILE TOPS ARE BEING BLOWN OFF TO
THE SE. WINDS ARE NE-ENE 5-10 KT...HIGHEST AT THE COASTAL
TERMINALS.
SHOWERS WILL CONTINUE TO DEVELOP TODAY WITH RAINFALL BECOMING
MORE WIDESPREAD AND MODERATE TO HEAVY AT TIMES. CONFIDENCE IS HIGH
THERE WILL BE PERIODS OF MVFR CIGS/VSBYS THROUGH THIS AFTERNOON
ASSOCIATED WITH THE SHOWER ACTIVITY. IFR COULD OCCUR IF CELLS
MOVE DIRECTLY OVER A TERMINAL. DUE TO COVERAGE FEEL THE CHANCE OF
GOOD TIMING OF IFR VSBYS WITH THE SHOWERS AT ANY SPECIFIC TERMINAL
WILL BE LOW.
MODELS ALL AGREE THERE WILL BE A DECREASE IN SHOWER ACTIVITY THIS
EVENING AND OVERNIGHT. IFR CONDITIONS IN FOG WILL DEVELOP AT
KFLO/KLBT AFTER MIDNIGHT...WITH TEMPO LIFR POSSIBLE 09-12Z. THE
COASTAL TERMINALS SHOULD REMAIN MVFR OR GREATER.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. THIS FEATURE WILL INTERACT WITH A HIGH PRESSURE
WEDGE INLAND TODAY AND TONIGHT. A CAUTION STATEMENT CANNOT BE
RULED OUT LATER TODAY OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE
MAY NOT NEED ONE. TSTMS AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE
WATERS AND THIS WILL REDUCE VSBYS LESS THAN 1 NM AT TIMES.
MARINERS SHOULD CONSIDER GETTING A RADAR BRIEFING OR LOOK BEFORE
HEADING OUT TODAY OR TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E
WAVES 3 FEET EVERY 3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10
SECOND INTERVALS. ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK
TUESDAY BUT WIND SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT
DOES REMAIN OVERHEAD OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
730 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONCERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. PRECIP HAS BEEN EXPANDING OVER THE FOOTHILLS THIS MORNING
AND WILL SLOWLY SPREAD EAST ACROSS THE TRIAD THROUGH MIDDAY. LOW
CLOUDS WILL CONTINUE TO BE FAVORED OVER WESTERN PORTIONS OF THE
AREA...WITH MVFR CEILINGS LIKELY LOWERING TO AT LEAST IFR AT
KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW FAR EAST THE SUB-
VFR CEILINGS WILL EXPAND TO THE EAST...SO CONFIDENCE IN MVFR OR IFR
CEILINGS AT KRDU IS LOWER. HOWEVER...THE MOST RECENT RAP AND HRRR
SHOW LESS STRATUS AT KRDU...KRWI AND KFAY...WITH CEILINGS HOVERING
AT HIGH END MVFR OR ABOVE. SHOWERS WILL ALSO BE POSSIBLE IN THE
VICINITY OF KFAY BY THIS AFTERNOON. SUB-VFR CEILINGS ARE THEN LIKELY
TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
928 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE ACROSS EAST-CENTRAL INDIANA WILL DRIFT NORTHWARD
REACHING LAKE HURON BY TUESDAY MORNING. THIS WILL TAKE A WARM
FRONT NORTH ACROSS THE AREA TODAY AND A COLD FRONT TUESDAY. THE
LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS WORKING NORTH INTO THE AREA WITH
ADDITIONAL SHOWERS/THUNDERSTORMS DEVELOPING OVERHEAD TODAY.
OVER THE NEXT COUPLE OF DAYS A BROACH UPPER TROUGH WILL ENCOMPASS
THE EASTERN GREAT LAKES AND NEW ENGLAND. LOW PRESSURE ACROSS EAST
CENTRAL INDIANA WILL MOVE NORTH TOWARD LAKE HURON TODAY. MOISTURE
LEVELS ARE HIGH AND RAINFALL RATES COULD POTENTIALLY BE WILL BE AS
WELL. PRECIPITABLE WATER VALUES WILL NEAR 2 INCHES BY THIS
AFTERNOON. AREA IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY/OUDEMAN
NEAR TERM...LOMBARDY/OUDEMAN
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
736 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE BEGINNING TO DEVELOP RIGHT ON
SCHEDULE. WILL CONTINUE TO SEE A GRADUAL EXPANSION OF THE
PRECIPITATION THROUGH THE DAY. MADE A MINOR UPDATE TO CURRENT
HOURLY TEMPERATURES. OTHERWISE...NO MAJOR CHANGES EXPECTED WITH
THIS UPDATE.
PREVIOUS DISCUSSION...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
622 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE BEGINNING TO DEVELOP RIGHT ON
SCHEDULE. WILL CONTINUE TO SEE A GRADUAL EXPANSION OF THE
PRECIPITATION THROUGH THE DAY. MADE A MINOR UPDATE TO CURRENT
HOURLY TEMPERATURES. OTHERWISE...NO MAJOR CHANGES EXPECTED WITH
THIS UPDATE.
PREVIOUS DISCUSSION...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1003 AM EDT MON AUG 11 2014
.DISCUSSION...
JUST ISOLATED SHOWERS OVER THE NORTHERN HALF OF THE AREA
NOW...EXPECTING AFTERNOON HEATING TO GET ISOLATED CONVECTION
GOING...AND WILL SEE HOW WELL THE SMALL COMPLEX OVER SRN KY HOLDS
TOGETHER FOR THS AFTERNOON. HRRR SUGGEST MORE CONVECTION IN THE
WESTERN AREAS IN THE EARLY AFTERNOON. FORECAST LOOKS ON TRACK...SO
NO UPDATE TO THE ZONE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 86 71 88 66 / 50 60 40 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 71 86 65 / 60 50 50 20
OAK RIDGE, TN 83 70 86 64 / 60 60 40 20
TRI CITIES AIRPORT, TN 81 66 83 61 / 60 70 60 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
GM
SEE FORECAST DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
THE NEXT COLD FRONT THAT IS FORECASTED TO MOVE INTO THE AREA THIS
EVENING IS CURRENTLY LOCATED IN NORTH TEXAS AND WILL CONTINUE TO
SLOWLY MOVE SOUTHWARDS THIS AFTERNOON. A HAND ANALYSIS OF 12Z
MAPS AT 850 AND 700MB THIS MORNING REVEALS TWO BOUNDARIES NEAR
KCLL WITH THE BEST MOISTURE JUST EAST OF THE AREA. AT 250MB A WEAK
UPPER LEVEL LOW WAS ANALYZED JUST SOUTH OF THE AREA WHICH IS
HELPING TO PROVIDE DIFFLUENT WINDS IN NORTHERN TEXAS THIS MORNING.
THE LOW IS FORECASTED TO CONTINUE TO PUSH SOUTH THIS AFTERNOON
ALLOWING THE UPPER LEVEL DIFFLUENCE ALSO TO SAG SOUTHWARDS. HIGH
RES HRRR AND RAP HAVE INITIALIZED THE BEST THIS MORNING AND FIRE
CONVECTION IN TWO AREAS. THE FIRST BEING A SEA BREEZE PUSHING
INLAND AND ALONG A COLD FRONT THAT IS PUSHING SOUTHWARDS. IT
SHOULD BE NOTED THE HRRR AND RAP FIRE WIDESPREAD CONVECTION IN OUR
NORTHERN ZONES THIS AFTERNOON. WAS TEMPTED TO GO LIKELY FOR POPS
BUT HAVE HELD OFF FOR NOW. FORECAST FOR THIS AFTERNOON REVEAL
PWATS NEAR 2.00" WITH K INDEX VALUES AROUND 40. FORECAST SOUNDINGS
ALSO SHOW AN INVERTED V THIS AFTERNOON. THIS COULD LEAD TO SOME
GUSTY WINDS IN STRONGER STORMS. IF CONVECTION GETS MORE WIDESPREAD
THIS AFTERNOON THIS WILL ALSO HOLD DOWN HIGH TEMPERATURES. FOR NOW
HAVE ONLY MADE MINOR TWEAKS TO GRIDS. 23
&&
.PREV DISCUSSION... /ISSUED 357 AM CDT MON AUG 11 2014/
DISCUSSION...
COOL FRONT SITUATED IN S OKLAHOMA EARLY THIS MORNING SHOULD MAKE
GRADUAL SWD PROGRESS & CLOSER TO N PARTS OF SE TX LATER THIS
EVENING. WITH AID OF DAYTIME HEATING EXPECT SHRA/TSTM COVERAGE
ALONG THE FRONT TO INCREASE THIS AFTN AND APPROACH N PARTS OF THE
CWA LATER IN THE DAY. FURTHER SOUTH & TOWARD THE COAST...ANTICIPATE
ISO/SCT PRECIP DEVELOPMENT ALONG THE SEABREEZE SIMILAR TO PAST
COUPLE DAYS.
THINGS GET INTERESTING THIS EVENING AND OVERNIGHT. REALLY NEED TO
KEEP AN EYE ON REGION BETWEEN THE SEABREEZE (OR REMNANTS OF) AND
THE CONVECTION DRIFTING IN FROM THE NORTH. SHOULD THESE EVENTUALLY
COLLIDE/MERGE...AND SEVERAL MODELS SUGGEST IT`S QUITE POSSIBLE...THREAT
OF LOCALIZED HEAVY RAINFALL REALLY INCREASES. GOES SOUNDER DATA SHOWING
PW`S AROUND 2.2" ACROSS THE REGION WHICH IS ABOUT 2 STANDARD DEVIATIONS
ABOVE NORMAL. WITH FAIRLY WEAK STEERING FLOW IN PLACE...LOCALIZED
BOUNDARY COLLISIONS WILL ENHANCE LIFT AND THREAT OF STORMS GOING
NEARLY STATIONARY INCREASES. ATTM HIGHER THREAT OF THIS OCCURRING
WILL PROBABLY BE SOMEWHERE ROUGHLY BETWEEN I-10 AND SOMERVILLE-
TRINITY LINE BETWEEN 7PM-MIDNIGHT.
FRONT AND ASSOCIATED PRECIP SHOULD MAKE GRADUAL SOUTHWARD
PROGRESS OVERNIGHT AND TOWARD THE COAST TUE. EXACTLY WHERE IT ENDS
UP IS IN QUESTION, BUT MAJORITY OF 00Z RUNS WITH EXCEPTION OF
NAM12 ACTUALLY PUSH IT *BRIEFLY* OFFSHORE LATE TUE NIGHT & WED
MORNING. SCT CONVECTION WILL REMAIN POSSIBLE ALONG/S OF THE FRONT.
LOWERED POPS ACROSS MOST AREAS NORTH OF I-10 TUESDAY AND INTO
MIDWEEK AS A CONSIDERABLY DRIER AIRMASS MOVES INTO THE REGION.
ANYONE UP FOR DEWPOINTS IN THE 50S/60S & HUMIDITIES 30-40%? HOW
ABOUT A FEW LOWS IN THE UPPER 60S IN THE NORTH HALF? LOOKING MORE
AND MORE LIKE A DECENT POSSIBILITY INTO MIDWEEK.
A GRADUAL RETURN BACK TO AUGUST REALITY EXPECTED DURING THE 2ND
HALF OF THE WEEK AND INTO THE WEEKEND AS THE FRONT WASHES OUT. ONSHORE
WINDS RESUME AS LEE SIDE PRESSURES FALL. MOISTURE LEVELS INCREASE
AGAIN WITH TYPICAL ISO SEABREEZE PRECIP. 47
MARINE...
LIGHT ONSHORE WINDS TODAY SHOULD BECOME MORE VARIABLE TUES/WEDS AS A
WEAK SFC FRONT SAGS INTO THE REGION. THIS BOUNDARY IS FCST TO SLOWLY
MAKE ITS WAY TO THE UPPER TX COASTLINE LATE MON/EARLY TUES...BUT NOT
EXPECTED TO MOVE INTO THE NEARSHORE WATERS AT THIS TIME. THE PROXIM-
ITY OF THIS SYSTEM SHOULD GENERATE PERIODS OF SHRAS/TSRAS FROM EARLY
TUES THROUGH WEDS. THIS BOUNDARY IS PROGGED TO WASH OUT THURS...WITH
THE NEXT STORM SYSTEM MOVING INTO THE STATE AND DEEPENING AROUND THE
SAME TIME. THIS SHOULD PRODUCE STRENGTHENING ONSHORE WINDS BY FRI...
AND ON INTO THE WEEKEND. 41
AVIATION...
NO REAL CHANGE FROM THE FCST OF PERSISTENCE WITH THE 12Z SET OF TAFS
THROUGH THIS AFTN. STILL EXPECTING A SOMEWHAT ACTIVE SEABREEZE AS WE
REMAIN IN A FAIRLY TROPICAL AIRMASS. CHANGES EXPECTED TO COME DURING
THE OVERNIGHT/EARLY TUES MORNING TIME FRAME AS A WEAK FRONTAL BOUND-
ARY MOVES INTO THE REGION FROM THE NORTH. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 74 96 70 96 / 50 50 10 10 10
HOUSTON (IAH) 95 75 94 73 95 / 30 50 30 20 20
GALVESTON (GLS) 93 81 89 80 92 / 20 50 40 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
940 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 935 AM MDT MON AUG 11 2014
NO MAJOR WEATHER CONCERNS TODAY AS A HIGH AMPLITUDE UPPER-LEVEL
RIDGE CONTINUES TO BUILD INTO THE AREA. LINGERING MOISTURE ALOFT
WILL AID IN AT LEAST ISOLATED COVERAGE OF SHOWERS AND TSTMS OVER
THE MOUNTAINS...BUT OTHERWISE SOUTHEAST WYOMING SHOULD REMAIN ON
THE DRY SIDE. THE ONLY CHANGE TO THE INHERITED GRIDS CONCERNS PCPN
CHANCES OVER THE PANHANDLE. WATER VAPOR SATELLITE SHOWS CONTINUED
NORTHWEST FLOW ALOFT ON THE EAST SIDE OF THE RIDGE...ATOP A WEAK
SFC MOISTURE BOUNDARY ANALYZED FROM NORTH TO SOUTH ACROSS THE HIGH
PLAINS. GOOD LLVL MOISTURE WITH DEWPOINTS AROUND 60F SUGGESTS PTNL
FOR ISOLATED CONVECTION. ADDED SLIGHT CHANCE POPS FOR THOSE ZONES
AS THIS SETUP IS VERY SIMILAR TO YESTERDAY. HRRR COMPOSITE RADAR
REFLECTIVITY ALSO HINTS AT THIS. WILL NEED TO WATCH FOR A STRONGER
STORM OR TWO AS THE LATEST SPC MESOANALYSIS INDICATES AROUND
1000-1500 J/KG CAPES AS OF 15Z. COVERAGE SHOULD BE MINIMAL. ALL
OTHER ASPECTS OF THE FCST ARE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 415 AM MDT MON AUG 11 2014
A HIGH AMPLITUDE UPPER RIDGE WILL REMAIN OVER THE WESTERN CONUS TO
START THE WEEK...AND WILL SHIFT EAST TOWARD THE HIGH PLAINS BY
WEDNESDAY. CURRENT WATER VAPOR IMAGERY SHOWS A DRY DEFORMATION ZONE
OVER WYOMING WITH JUST A FEW MID/HIGH CLOUDS PASSING THRU OUR
NORTHERN ZONES ON THE WESTERN EDGE OF A STRONGER JET DIVING INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. PERSISTENT SURFACE HIGH
PRESSURE OVER THE CENTRAL PLAINS WILL MAINTAIN EAST-SOUTHEASTERLY
UPSLOPE FLOW ACROSS THE HIGH PLAINS OF WYOMING AND WESTERN
NEBRASKA TODAY. SOME OF THE MIDLEVEL MOISTURE ASSOCIATED WITH THE
UPPER JET WILL REMAIN OVER THE REGION...AND COMBINED WITH THE
UPSLOPE FLOW...COULD SEE A FEW T-STORMS DEVELOP OVER THE MOUNTAINS
OF SOUTHEAST WYOMING THIS AFTERNOON. ANY STORMS THAT DO DEVELOP
WILL REMAIN WEAK AND WILL LIKELY PRODUCE VERY LITTLE RAINFALL AS
LI`S WILL BE ROUGHLY MINUS 1 UNDER WEAK WINDS ALOFT.
THE UPPER RIDGE AXIS WILL SHIFT EAST OVER THE ROCKIES FOR TUESDAY
WITH SOME WEAK MIDLEVEL ENERGY AND MOISTURE MOVING UP FROM THE
SOUTHWEST TOWARD THE CWA. CONVECTION LOOKS TO REMAIN CONFINED TO THE
MOUNTAINS AND NEARBY VALLEYS AS THIS AREA WILL BE CLOSER TO THE
MOISTURE AND ENERGY...ALTHOUGH COVERAGE LOOKS TO REMAIN QUITE
ISOLATED STILL. TEMPS WILL TREND UPWARD AS THE UPPER RIDGE AXIS
SHIFTS OVERHEAD...WITH 700MB TEMPS INCREASING TO BE 12 TO 16C BY
TUESDAY AFTERNOON.
A STRONGER SHORTWAVE WILL APPROACH THE CWA FROM THE SOUTHWEST ON
WEDNESDAY AFTERNOON AND WILL DRAG WITH IT A DEEPER FETCH OF
SUBTROPICAL MOISTURE. THE LEESIDE PRESSURE TROUGH WILL DEEPEN IN
ADVANCE OF THIS WAVE...IN ADDITION TO A SECOND WAVE MOVING THRU
MONTANA. CONVERGENCE WITHIN THE SFC TROUGH WILL BRING A BETTER
CHANCE FOR SHOWERS AND STORMS TO THE EASTERN PLAINS OF WYOMING AND
NEBRASKA WEDNESDAY AFTERNOON...WHILE GENERAL OROGRAPHIC CONVECTION
LOOKS A GOOD BET WITH SUPPORT FROM THE SHORTWAVE FEATURE. PWATS
WILL INCREASE TO ROUGHLY ONE INCH OR HIGHER BY WEDNESDAY
AFTERNOON...SO THIS ACTIVITY COULD PRODUCE MODERATE TO LOCALLY HEAVY
RAIN AT TIMES THROUGH THE AFTERNOON. WINDS AT THE JET LEVEL WILL
INCREASE TO BE 30-40 KTS...BUT WILL STILL BE WEAK AT 500 MB AND
BELOW SO TO POTENTIAL FOR STORMS TO BECOME ORGANIZED LOOKS TO BE
MINIMAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM MDT MON AUG 11 2014
STARTING OFF WEDNESDAY NIGHT...MONSOONAL MOISTURE STILL OVER THE
AREA WHICH WILL INTERACT WITH A SHORTWAVE MOVING THROUGH THE UPPER
LEVEL RIDGE. BOTH THE GFS AND ECMWF PRETTY SIMILAR WITH SHOWERS
OVER THE SOUTHERN CWFA. SOME DIFFERENCES BETWEEN THE TWO FOR
THURSDAY.
LATEST ECMWF SHOWS SOME ENERGY COMING OFF THE CLOSED LOW OVER THE
PACNW FURTHER WEST THAN THE GFS FOR THURSDAY AFTERNOON. AS A
RESULT...MORE WIDESPREAD SHOWERS AND QPF ARE OVER THE WESTERN HALF
OF THE CWFA COMPARED TO THE GFS SOLUTION. PWATS OVER RAWLINS
APPROACHING 1 INCH WITH FORECAST STORM MOTIONS UNDER 5KTS. OVER
HERE BY CHEYENNE...FORECAST PWATS 1.2 INCHES AND BY SIDNEY...1.5
INCHES. SHOULD BE VERY EFFICIENT RAIN PRODUCERS FOR THURSDAY
AFTERNOON. CONTINUED CHANCE POPS FOR MOST OF THE CWFA WITH BEST
CHANCES IN THE MOUNTAINS.
BIGGER DIFFERENCES FOR FRIDAY. GFS HAS US DRY FOR FRIDAY AFTERNOON
WHILE THE ECMWF BRINGS ANOTHER PIECE OF ENERGY OFF THAT CLOSED LOW
INTO THE AREA. IF THE ECMWF COMES TRUE...WE WILL BE LOOKING AT
HEAVY RAINFALL ONCE AGAIN FRIDAY AFTERNOON AND EVENING. KEPT SOME
LOW CHANCE POPS IN THE FORECAST FOR THIS TIME FRAME.
CLOSED LOW FINALLY MOVES THROUGH NORTHERN MONTANA FOR SATURDAY AND
WE WILL SEE THE RETURN OF DRY WEATHER TO WYOMING. COULD START TO
GET BREEZY SATURDAY AS GFS 700MB WINDS HIT 20KTS SATURDAY
AFTERNOON AND 25KTS SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 428 AM MDT MON AUG 11 2014
VFR CONDITIONS EXPECTED AT ALL SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE AIRPORTS TODAY AS HIGH PRESSURE REMAINS OVER COLORADO.
COULD SEE ISOLATED TO WIDELY SCATTERED AFTERN AND EARLY EVENING
THUNDERSTORMS OVER THE MOUNTAINS TODAY...BUT THAT CHANCE IS SMALL.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT MON AUG 11 2014
MOSTLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY WITH ONLY A FEW
T-STORMS EXPECTED IN THE AFTERNOON FOR THE MOUNTAINS OF SOUTHEAST
WYOMING. THESE STORMS WILL BE WEAK AND SHOULD PRODUCE VERY LITTLE
RAINFALL. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTHERN AND WESTERN PORTIONS OF CARBON COUNTY MONDAY
AND TUESDAY AFTERNOONS...HOWEVER WINDS IN THIS AREA WILL FOR THE
MOST PART AVERAGE 10 MPH OR LESS. THE EXCEPTION WILL BE IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS WHERE WINDS WILL BE
VARIABLE AND GUSTY. INCREASING MONSOONAL MOISTURE AND STRONGER
UPPER LEVEL DISTURBANCES WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SHOWER COVERAGE DECREASES
LATE IN THE WEEK AS THE UPPER RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
930 AM MST MON AUG 11 2014
.SYNOPSIS...
MOISTURE LEVELS HAVE INCREASED OVER THE PAST COUPLE DAYS AND WILL
CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES FOR MONSOON RAIN
THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR RAIN WILL BE
TUESDAY AND WEDNESDAY AS A WEATHER DISTURBANCE MOVES NORTHWARD
THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL LEVELS WITH
THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY CLOUDY SKIES
SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER CONDITIONS
EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK OVER THE
REGION.
&&
.DISCUSSION...
A COMPLEX WEATHER SCENARIO IS SHAPING UP FOR THE NEXT COUPLE OF DAYS
WITH SOMEWHAT LIMITED MOISTURE TODAY...BUT WIDESPREAD AND VERY MOIST
CONDITIONS FOR TUESDAY INTO WEDNESDAY. MORNING RAOBS FOR PHOENIX AND
TUCSON BOTH SHOW FAIRLY MOIST AND UNSTABLE PROFILES WITH SLIGHTLY
DRIER CONDITIONS FOR PHOENIX. SOUNDINGS STILL SHOW AN INVERTED-V
TYPE STRUCTURE WITH NEAR SATURATED AND CONDITIONALLY UNSTABLE
MID-LEVELS. A CLOSED LOW CENTERED OFF THE COAST OF CENTRAL
CALIFORNIA CONTINUES TO BRING BROAD UPPER DIFFLUENCE ACROSS MUCH OF
SOUTHERN CALIFORNIA AND ARIZONA WITH A WEAK UPPER JET MAX SITUATED
FROM SAN DIEGO TO LAS VEGAS. THIS JET MAX IS CURRENTLY AIDING IN
ISOLATED SHOWER ACTIVITY ACROSS RIVERSIDE COUNTY...SO HAVE UPDATED
THE FORECAST POPS TO CHANCE IN THIS AREA THROUGH LATE MORNING.
ELSEWHERE...SKIES HAVE CLEARED OUT CONSIDERABLY SINCE EARLY MORNING
WHICH WILL ALLOW FOR A FAIRLY WARM DAY WITH HIGHS PEAKING A COUPLE
DEGREES ABOVE NORMAL.
THE FORECAST FOR THIS AFTERNOON AND EVENING REMAINS FAIRLY DIFFICULT
AS HI-RES MODELS ALL TELL A DIFFERENT STORY. WITH AMPLE MOISTURE IN
PLACE AND SOMEWHAT UNSTABLE ENVIRONMENT EXPECTED BY EARLY AFTERNOON
WE WILL SEE STORMS FIRE ALONG THE MOGOLLON RIM AND OVER SOUTHEAST
ARIZONA. THE STEERING FLOW IS MORE SOUTHEASTERLY TODAY VERSUS
YESTERDAY/S EASTERLY FLOW...SO WE SHOULD EXPECT BETTER CHANCES OF
ANY SOUTHEASTERN ARIZONA ACTIVITY VENTURING INTO THE LOWER DESERTS
BY LATE THIS AFTERNOON AND EVENING. IF A STRONG ENOUGH COLD POOL IS
GENERATED BEHIND ORGANIZED STORM OUTFLOWS...THERE IS A DECENT
LIKELIHOOD OF AT LEAST ISOLATED TO SCATTERED STORM DEVELOPMENT
ACROSS THE LOWER DESERTS THIS EVENING. FLOW ALOFT IS STILL FAIRLY
WEAK...SO THE DAMAGING WIND THREAT WILL BE MINIMAL...BUT CAN/T RULE
OUT A FEW STRONG WIND GUSTS.
FOR TONIGHT...INDICATIONS ARE POINTING TOWARD A CONTINUATION OF THE
SHOWER/STORM ACTIVITY WESTWARD THROUGH SOUTHERN ARIZONA...POSSIBLY
INTO SOUTHEAST CALIFORNIA LATE TONIGHT. THIS WILL ALL DEPEND ON THE
STRENGTH AND THE PROGRESSION OF STORM OUTFLOWS GENERATED FROM
EARLIER EVENING STORMS. PLAN TO MAKE ADJUSTMENTS TO INCREASE
TONIGHT/S POPS ACROSS SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA FOR
THE AFTERNOON FORECAST PACKAGE.
&&
.PREVIOUS DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG
DOWNBURST WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND
LOCALIZED FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SCT-BKN MID LEVEL CLOUD DECKS AOA 12K FT...AND WINDS REMAINING
GENERALLY EASTERLY THROUGH THE DAY. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING OVER HIGHER TERRAIN NORTH/EAST/SOUTH OF
TERMINALS AFTER 19Z...A FEW STORMS AFFECTING TERMINALS AFTER 00Z
TUESDAY AS SOUTHEASTERLY STEERING FLOW WILL HELP MOVE STORMS INTO
LOWER DESERTS. EXPECT LOCAL CIGS DOWN TO 8KFT WITH STORMS THAT
APPROACH TERMINALS...ALONG WITH POTENTIAL FOR VISIBILITY REDUCTIONS
DOWN TO 1SM OR LESS IN AREAS OF BLOWING DUST AND 40-45KT OUTFLOW
WINDS. STORM ACTIVITY EXPECTED TO PERSIST UNTIL AROUND 06Z TUESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT-BKN MID LEVEL CLOUDS GENERALLY AOA 12K PERSISTING THROUGHOUT THE
DAY...WITH ISOLATED THUNDERSTORMS POSSIBLE DURING THE LATE AFTERNOON
AND EVENING...FORMING EAST-SOUTHEAST OF KNYL/YUMA. NOT OUT OF THE
QUESTION FOR OUTFLOW WINDS FROM DISTANT STORMS TO CAUSE WIND SHIFTS
AT TERMINALS LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHTER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1208 PM EDT MON AUG 11 2014
.SYNOPSIS...
WHILE FAIR WEATHER WITH AN AN ISOLATED SHOWER OR THUNDERSTORM IS
POSSIBLE TODAY...A SLOW MOVING AND COMPLEX LOW PRESSURE SYSTEM
WILL BRING WET WEATHER TO THE REGION TUESDAY NIGHT INTO WEDNESDAY
NIGHT. GRADUALLY IMPROVEMENT AND DRYING IS THEN EXPECTED INTO
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1205 PM UPDATE...
SPC MESO-ANALYSIS SHOWING 500 TO 1000 J/KG OF CAPE HAS DEVELOPED AT
NOON IN A WEAKLY CAPPED ENVIRONMENT. AS A RESULT...ISOLATED SHOWERS
WERE BEGINNING TO POP ACROSS THE REGION. THE HRRR MODEL SEEMS TO
HAVE GOOD HANDLE ON THIS WITH THE THREAT FOR WIDELY SCATTERED
SHOWERS CONTINUING THROUGH THE AFTERNOON. AN ISOLATED THUNDERSTORM
OR TWO IS ALSO POSSIBLE...BUT WITH WEAK WIND FIELDS NOT EXPECTING
SEVERE WEATHER. SLOW MOVEMENT MAY ALLOW FOR BRIEF HEAVY RAINFALL IN
A FEW LOCALES.
OVERALL...MUCH OF THE REGION WILL REMAIN DRY AS THIS ACTIVITY WILL
REMAIN WIDELY SCATTERED. UNDER A MIXTURE OF CLOUDS AND SUN
AFTERNOON HIGHS SHOULD MAINLY BE IN THE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
WITH DAYTIME HEATING CONCLUDING...ANY BOUNDARY-LAYER LIFT AND / OR
CONVERGENCE CONCLUDES. HIGH PRESSURE RIDGE REMAINS IN CONTROL...
SINKING AIR WILL ALLOW FOR CLEAR CONDITIONS UNTIL LATE WHEN THIN-
HIGH CLOUDS BEGIN TO FILTER ACROSS THE REGION AHEAD OF THE MIDWEEK
DISTURBANCE.
S-FLOW CONTINUES ADVECTING HIGHER DEWPOINT AIR ONSHORE AND THIS
SHOULD RESULT IN A MILD NIGHT WITH LOW AROUND THE LOW-60S. COMBINED
WITH CONTINUED SINKING AIR...COULD SEE A MIX OF /OR EITHER/ PATCHY
DENSE FOG AND LOW CLOUDS AS MOISTURE POOLS BENEATH THE INVERSION.
MODELS NOT QUITE SUCCINCT ON OUTCOMES AND THERE IS A LAYER OF
UNCERTAINTY.
TUESDAY...
DEEPENING TROUGH OVER THE GREAT LAKES REGION SUBSEQUENTLY AMPLIFIES
THE DOWNSTREAM RIDGE ACROSS NEW ENGLAND AND TO THE E. THIS KEEPS
HIGH PRESSURE IN CONTROL OF THE REGIONS WEATHER MOST OF THE DAY. DRY-
SINKING AIR LINGERS AS BEEN THE CONSISTENT SIGNAL OVER THE LAST
SEVERAL DAYS WORTH OF MODEL-GUIDANCE.
THERE ARE TWO CAMPS OF FORECAST SOLUTIONS: THE ECWMF / GFS BRINGING
RAIN INTO THE CT-VALLEY REGION BY 8 PM TUESDAY...WHEREAS THE NAM /
CANADIAN / WRF KEEP THE AREA COMPLETELY DRY. AS NOTED BY THE PRIOR
FORECASTER...LOW-LEVEL-JET /LLJ/ AXIS WITHIN H925-85 REMAINS W OF
THE REGION ALONG WITH ATTENDANT LOW-LEVEL MOIST CONVERGENCE.
INCREASING ISENTROPIC MOTIONS AND DIFFLUENCE ALOFT PER ALL FORECAST
GUIDANCE AS THE RIDGE SHIFTS E IS A LIKELY CULPRIT FOR ADVECTING THE
HIGH MOISTURE CONTENT THROUGH THE LLJ EASTWARD. SUBSEQUENTLY...WILL
KEEP WITH CHANCE POPS AND MAINLY CONFINE THEM TO THE CT-RIVER VALLEY
REGION BY THE END OF THE PERIOD. FEEL THE E-SHIELD OF PRECIPITATION
WILL ERODE AGAINST THE LINGERING COLUMN OF DRIER AIR.
ANTICIPATING BRISK ONSHORE SE-FLOW CONTINUALLY INCREASING DEWPOINTS
AND HUMIDITY. WHILE SCATTERED-BROKEN CUMULUS DEVELOPS...EXPECT A TOP-
DOWN MOISTENING RESULTING IN THICKENING AND LOWERING MID- TO UPPER-
LEVEL CLOUDS TOWARDS THE LATER-HALF OF THE DAY. THIS SHOULD KEEP
CONDITIONS JUST SLIGHTLY COOLER WITH HIGHS AROUND THE LOW-80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
ANOMALOUS UPPER LVL PATTERN /DEEP CUTOFF WITH CONNECTION TO BAFFIN
ISLAND CUTOFF IS EXPECTED TO SETTLE IN ACROSS THE REGION MID WEEK
INTO THE LATTER HALF OF THE WEEK. THIS FEATURES A CUTOFF LOW PRES
GRADUALLY SLIDING E OF THE GREAT LAKES WED-THU...THEN SLOWLY
FILLING AND LIFTING TO THE N FOR FRI INTO THE WEEKEND. THIS STILL
FAVORS UNSETTLED WET WX FOR TUE NIGHT INTO WED NIGHT. THE KEY IS
TIMING...IT NOW APPEARS THAT INITIALLY ECMWF MAY BE THE FAST
OUTLIER FOR TUE NIGHT...BRINGING PRECIP IN TOO FAST IN A BUILDING
RIDGE REGIME. THEREFORE...WILL LEAN ON 00Z GFS AND NAM FOR THE
START. HOWEVER...DO PREFER THE SLOWER TIMING OF PRECIP EXIT GIVEN
THE INCOMING UPPER LVL CUTOFF AND UPPER LVL JET ENERGY IN THE
ECWMF...SO WILL BE LEANING BACK ON IT FOR WED NIGHT INTO THU. FOR
THE REMAINDER OF THE FORECAST...A BLEND OF ENSEMBLES CONTINUES
PROVIDE A GOOD MIDDLE GROUND FOR THE SLOW EXIT OF THIS CUTOFF
DURING THE LATER HALF OF THE WEEK.
DETAILS...
TUE NIGHT INTO WED NIGHT...
DEEP AUGUST CUTOFF WILL BE DEVELOPING WITHIN VICINITY OF THE GREAT
LAKES. THIS WILL LEAD TO A FULL FLEDGED OCCLUSION DEVELOPING IT
AND WHAT APPEARS TO BE FAIRLY HIGH LIKELIHOOD OF TRIPLE POINT LOW
DEVELOPMENT OVER SRN NEW ENGLAND. THIS WILL LEAD TO SEVERAL
POTENTIAL IMPACTS ACROSS THE REGION LATE TUE NIGHT AND THROUGH THE
DAY ON WED AS FOLLOWS...
HEAVY RAIN AND FLASH FLOOD THREAT...
VERY HIGH PWATS APPROACHING 2.0 INCHES /ALMOST 3 STD DEVIATIONS
ABOVE NORMAL/ COMBINED WITH STRONG UPWARD MOTION WITH DEVELOPING
TRIPLE POINT LOW AND STRONG 40-50 KT SLY LLJ WILL ALL FALL IN LINE
TO LEAD TO THE POTENTIAL FOR BANDS OF HEAVY RAIN AIDED BY CONVECTIVE
PROCESSES BEGINNING LATE TUE NIGHT AND CONTINUING INTO WED
AFTERNOON. THIS MAY LEAD TO A LOCALIZED URBAN/POOR DRAINAGE AND
POSSIBLY EVEN SMALL STREAM FLASH FLOOD THREAT SHOULD TRAINING
BECOME AN ISSUE. TOTAL QPF VALUES OF 1.5 INCHES ARE POSSIBLE BUT
SOME 2-3 INCH AMOUNTS CANNOT BE RULED OUT...WITH MUCH OF THIS
POTENTIALLY FALLING OVER A SHORT STRETCH OF TIME. WILL ALSO NEED
TO MONITOR LOCATIONS WHERE TIDES EFFECT DRAINAGE CONSIDERING HIGH
SPRING TIDES WILL ACCOMPANY THIS STORM. STILL A FEW MESO-SCALE
TIMING UNCERTAINTIES WEED THROUGH...SO CONFIDENCE IS NOT HIGH
ENOUGH FOR A WATCH WITH THIS UPDATE...BUT IT WILL BE SOMETHING TO
LOOK AT FOR LATER.
SEVERE WEATHER POTENTIAL...
AS MENTIONED ABOVE THERE IS CERTAINLY ENOUGH LIFT WITHIN THE STRONG
OCCLUSION TO HELP WORK ON AVAILABLE INSTABILITY. AT THIS
POINT...DO NOTE SOME DRY AIR ENTRAINING INTO THE UPPER LVLS OF THE
COLUMN WHICH LOOK TO ENHANCE LATE WED LAPSE RATES SOMEWHAT.
ALSO...IN SPITE OF WHAT IS LIKELY TO BE A FAIR AMOUNT OF CLOUD
COVER AND ONSHORE FLOW...DO NOTE SOME CONDITIONALLY UNSTABLE
PROFILES WITH 500-1000J/KG OF CAPE. ALSO...THE 40-50 KT LLJ DOES
LEAD TO SHEAR PROFILES OF NEAR 25 KT...30 KT...AND 35-40 KT IN THE
0-1KM...0-3KM AND 0-6KM LAYERS RESPECTIVELY. SO CLEARLY A FAIRLY
PRONOUNCED LOW CAPE HIGH SHEAR ENVIRONMENT WITHIN AN AIRMASS THAT
SUPPORTS LOW LCLS OF 900MB OR POTENTIALLY LOWER. THERE IS SOME
UNCERTAINTY THOUGH MAINLY IN THE TIMING AND WHETHER THE LLJ/SHEAR
AND INSTABILITY PEAKS WILL COINCIDE AND WHEN...WHILE THIS IS
PARTIALLY A MODEL ISSUE...IT DOES APPEAR THE BEST LLJ ENERGY MAY
BE EARLY WHILE PEAK INSTABILITY IS CLOSER TO THE CLIMATOLOGICAL
NORM...LATER IN THE DAY. THIS IS IF IT DESTABILIZES AT ALL WITH
MARINE FLOW AND CLOUDS...AND THAT ANY DESTABILIZATION MAY BE MORE
ALOFT THAN AFT THE SFC. STILL WITH THIS PATTERN RESEMBLING WHAT AN
INTERNAL STUDY NOTES AS A TYPE-A PATTERN FOR NEW ENGLAND POTENTIAL
NEW ENGLAND TORNADO DEVELOPMENT...AND GIVEN ALL OF THE ABOVE
FACTORS...AN ISOLATED TORNADO SOMEWHERE IN NEW ENGLAND IS
POSSIBLE. IN ANY CASE...THE STRONG LLJ COULD PRODUCE SOME
STRONG/GUSTY WINDS IN SOME CONVECTIVE ELEMENTS WHICH WOULD HAVE TO
BE WATCHED AS WELL GIVEN THE SHEAR COULD SUPPORT SOME DISCRETE
STRUCTURES.
FINALLY...WITH ONSHORE FLOW AND DEVELOPING LOW PRES IN VICINITY OF
SRN NEW ENGLAND...COMBINING WITH HIGHER THAN NORMAL SPRING
TIDES...WILL HAVE TO MONITOR FOR SOME MINOR COASTAL FLOODING. FOR
MORE INFO...SEE THE COASTAL FLOOD SECTION BELOW.
THU INTO FRI...
UPPER LVL CUTOFF WILL BE SLIDING ACROSS NRN NEW ENGLAND...LEADING TO
A PERIOD OF CYCLONIC FLOW ACROSS THE REGION. A COUPLE OF WEAK
SHORTWAVES ARE LIKELY TO MOVE ACROSS THE AREA AND WORK ON SOME
TRAPPED LOW MOISTURE DESPITE WHAT WILL BE NEARLY STACKED W-NW
FLOW. GIVEN H5 TEMPS TOO DIP TO AROUND -14C...LOOKS LIKE SOME
DIURNAL CLOUDINESS WITH SPOT SHOWERS CAN/T BE RULED OUT ANY DAY.
H85 TEMPS WILL BE DIPPING TO POSSIBLY BELOW +10C...SO HIGHS ARE
LIKELY TO BE BELOW NORMAL UNLESS ENOUGH OF THE STILL RELATIVELY
HIGH AUGUST SUN ANGLE CAN BE REALIZED BETWEEN CLOUDY BREAKS.
NEXT WEEKEND AND EARLY NEXT WEEK... MODEL DIVERGENCE HERE...BUT A
BLEND OF ENSEMBLES AND EVEN THE OPERATIONAL ECMWF TO SOME EXTENT
FAVOR A GRADUAL IMPROVEMENT IN SENSIBLE WX THANKS TO BOTH THE FILLING
AND NORTHWARD LIFT OF THE UPPER LVL CUTOFF. THEREFORE...WILL
FEATURE A MAINLY DRY FORECAST ESPECIALLY AFTER SAT...WITH
GRADUALLY MODERATING TEMPERATURES.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...THROUGH TUESDAY.
TODAY...HIGH CONFIDENCE.
VFR. SOME SCT CU WITH CIGS 060-080 LATER IN THE DAY. OVERNIGHT...A
FEW MORE PATCHES OF FOG EXPECTED...ESPECIALLY AT TYPICALLY PRONE
AIRPORTS.
WINDS BEGIN LIGHT AND VRB...BUT THEN BEGIN TO SHIFT TOWARD THE
SE...THEN FINALLY MAINLY S BY LATE DAY. SEA BREEZES STILL LIKELY
AT THE COASTS WITH FAIRLY TYPICAL STARTING TIMES.
TUESDAY...MODERATE CONFIDENCE.
BREEZY S-WINDS. IFR-LIFR FOG AND CLOUDS IF PRESENT OVERNIGHT MAY
LINGER ALONG THE S-COAST. OTHERWISE CLOUDS LOWERING TO LOW-END
VFR. CHANCE OF SHRA LATE MAINLY ACROSS THE CT-RIVER VALLEY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF...SEA BREEZE STARTS AGAIN
13-14Z AND MAY SHIFT SLIGHTLY TOWARD THE SE.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUE NIGHT INTO WED NIGHT...MODERATE CONFIDENCE.
PERIODS OF MVFR/IFR LIKELY IN RAIN AND FOG. SOME ISOLATED
THUNDERSTORMS ALSO POSSIBLE. GUSTY WINDS POSSIBLE.
THU AND FRI...MODERATE CONFIDENCE.
ALTHOUGH SOME MVFR/IFR MAY LINGER IN SCT SHOWERS AND FOG EARLY
THU...EXPECT SOME IMPROVEMENT WITH MORE VFR THU DAY AND FRIDAY DAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...THROUGH TUESDAY...MODERATE CONFIDENCE.
INCREASING S-WINDS REMAINING BELOW 25 KTS ALONG WITH INCREASING
CHANCES OF COASTAL FOG ESPECIALLY DURING THE OVERNIGHT PERIODS.
EXPECTING DRY-WEATHER THROUGHOUT WITH SEAS REMAINING BELOW 5-FEET.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUE NIGHT THROUGH WED NIGHT...MODERATE CONFIDENCE.
THERE IS AN INCREASING THREAT FOR SMALL CRAFT ADVISORIES BEGINNING
LATE TUE NIGHT AND CONTINUING INTO WED NIGHT. ALTHOUGH WINDS WILL
BE SHIFTING FROM THE SW...THEN WILL BE VRB ON WED BEFORE SHIFTING
TO THE NW...SOME WINDS AROUND 25 KT CAN/T BE RULED OUT. ALSO...
SEAS WILL BE BUILDING...WITH 5-8FT SWELLS POSSIBLE ON THE OCEAN
WATERS.
THU AND FRI...MODERATE CONFIDENCE.
LOW PRES MOVES TO THE N OF THE REGION...THIS ALLOWS STRONG NW FLOW
TO DEVELOP...WHICH MAY REACH NEAR 25 KT AT TIMES THROUGH THE DAY
THU. SWELLS MAY TAKE SOME TIME TO SUBSIDE FROM THE WED STORM.
THEREFORE...SMALL CRAFT ADVISORIES ARE LIKELY TO LINGER IN SOME FORM
THROUGH THU. BY FRI...WINDS AND SEAS SHOULD GENERALLY BE BELOW
SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
WEDNESDAY...
A PERIOD OF HIGH SPRING TIDES WILL ACCOMPANY THE STRONG STORM DURING
THE DAY ON WEDNESDAY. THE ONSHORE FLOW FROM THIS STORM MAY LEAD TO
SOME MINOR COASTAL FLOODING AT MAINLY THE WEDNESDAY MID MORNING
/SOUTH COAST/ AND WEDNESDAY AFTERNOON /EAST COAST/ HIGH TIDES.
THE KEY QUESTION WILL BE THE TIMING OF A WAVE OF LOW PRES EXPECTED
TO MOVE ACROSS THE REGION...WHICH LOOKS LIKE IT MAY BE LATER IN THE
DAY THAT PREVIOUSLY THOUGHT. THIS MAY GENERATE JUST ENOUGH
ADDITIONAL SURGE. THERE IS STILL SOME UNCERTAINTY IN EXACTLY HOW
WIDESPREAD THE MINOR COASTAL FLOODING WILL BE...BUT TYPICALLY PRONE
LOCATIONS WILL BE AT HIGHEST RISK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
335 PM EDT MON AUG 11 2014
...FORECAST AREA REMAINS SPLIT BETWEEN WET CONDITIONS NORTH AND MUCH
DRIER CONDITIONS SOUTH...
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NEXT SIGNIFICANT
AMPLIFICATION TO THE MID/UPPER LEVEL PATTERN OVER THE EASTERN CONUS
QUICKLY EVOLVING SOUTHWARD THROUGH THE UPPER MIDWEST. AMPLIFIED
UPSTREAM RIDGING IS SEEN OVER MUCH OF THE INTER-MOUNTAIN WEST. THIS
PATTERN HAS BEEN SO PERSISTENT THIS SUMMER WITH THE WESTERN RIDGE
AND EASTERN TROUGH...AND IT DOES NOT LOOK TO BREAK ANYTIME THIS
WEEK. CLOSER TO HOME...OUR LOCAL AREA REMAINS UNDER THE INFLUENCE OF
WEAK WEST-EAST ORIENTED UPPER RIDGING. A UPPER LEVEL TUTT FEATURE IS
SEEN CLEARLY ON WV IMAGERY UNDER-CUTTING THE UPPER RIDGE...MIGRATING
WESTWARD THROUGH THE FLORIDA STRAITS AND NOW EMERGING INTO THE SE
GULF OF MEXICO. THIS FEATURE IS MOST DEFINED IN THE 400-200MB LAYER
AND IS HAVING THE EFFECT OF ENTRAINING DRIER AIR FROM THE EAST ALOFT
INTO ITS CIRCULATION AND OVER THE SOUTHERN FL PENINSULA.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE FAR
SOUTHERN FL PENINSULA WITH OUR FORECAST AREA RESIDING BETWEEN
THIS AXIS AND A QUASI-STATIONARY FRONTAL BOUNDARY NEAR/JUST NORTH OF
THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW IS FRONT THE SW. AS
THE LOW LEVEL SW FLOW ROUNDING THE RIDGE AXIS MEETS THE MORE
WESTERLY FLOW JUST AHEAD OF THE FRONT WE HAVE SET UP A PERSISTENT
CONVERGENCE BAND ACROSS THE NE GULF OF MEXICO. THIS LOW LEVEL FOCUS
FOR ASCENT IS HELPING TO FUEL SCT/NMRS SHOWERS AND ISOLATED STORMS
MIGRATING ONSHORE FROM ROUGHLY THE I-4 CORRIDOR NORTHWARD.
&&
.SHORT TERM (REST OF THIS AFTERNOON THROUGH TUESDAY)...
NUMEROUS SHOWERS/STORMS/CLOUDS FROM TAMPA BAY NORTHWARD CONTINUE
INTO THE EARLY EVENING HOURS. WITHOUT THE DEVELOPMENT OF A
SEA-BREEZE TO DISSIPATE THE CONVERGENCE ZONE OVER THE NORTHERN
COASTAL WATERS...THE FOCUS FOR SHOWERS HAS CONTINUED ALL DAY MOVING
ASHORE. LIKELY TO CATEGORICAL POPS (70-100%) FROM THE I-4 CORRIDOR
NORTHWARD WILL REMAIN IN THE GRIDS FOR SEVERAL MORE HOURS AT
LEAST...WITH RAIN CHANCES QUICKLY DECREASING TO THE SOUTH OF
HILLSBOROUGH/POLK COUNTIES. AS EXPECTED A FEW STORMS ARE BEGINNING
TO DEVELOP OVER THE INLAND PORTIONS OF THE SOUTHERN FORECAST
AREA...HOWEVER COVERAGE SHOULD REMAIN LIMITED. CLIMO COVERAGE FOR
THESE REGIONS DURING SW FLOW IN THE SUMMER IS (40-50%). WHEN WE ADD
IN THE DRIER AIR ALOFT...APPROX 30% COVERAGE SEEMS MORE REALISTIC.
SEEING A BIG DIFFERENCE IN TEMPERATURE FROM NORTH TO SOUTH. FREQUENT
SHOWERS/COOLER OUTFLOW/CLOUDS ARE HOLDING TEMPS IN THE UPPER 70S TO
MIDDLE 80S NORTH...WHILE SOUTH OF HILLSBOROUGH/POLK COUNTIES...LOWER
90S ARE COMMON.
LIKELY TO SEE THE SHOWERS DECREASE IN COVERAGE...EVEN OVER THE
NORTHERN HALF OF THE AREA...AS WE HEAD INTO THE MID/LATE EVENING
HOURS. WILL NOT COMPLETELY REMOVE RAIN CHANCES...BUT THE CONVERGENCE
SHOULD BE AT A MINIMUM LATER THIS EVENING INTO THE FIRST HALF OF THE
OVERNIGHT.
TUESDAY...
GLOBAL GUIDANCE HAS CONTINUED TO SHOW THE SUBTROPICAL RIDGE AXIS
MIGRATING A BIT TO THE NORTH (50-75 MILES) BY TUESDAY MORNING.
WHILE THIS MAY NOT SEEM LIKE MUCH...THIS DISPLACEMENT SHOULD NUDGE
THE BEST CONVERGENCE BAND TOMORROW TO THE NORTH AS WELL. DECIDED TO
FOLLOW THIS FORECAST PHILOSOPHY AND HOLD THE BETTER RAIN CHANCES
TUESDAY A BIT MORE TO THE NORTH OF TAMPA BAY (HERNANDO/SUMTER
COUNTIES NORTHWARD). THE PATTERN SEEN TODAY OVER THE SOUTHERN ZONES
WOULD THEN BE EXPANDED NORTHWARD TO ABOUT THE I-4 CORRIDOR...WITH
ONLY SCT ACTIVITY ACROSS HILLSBOROUGH/POLK COUNTIES...AND EVEN LESS
FURTHER SOUTH. THERE IS AGREEMENT BETWEEN THE GFS/ECMWF/AND SREF
ENSEMBLES IN THIS PATTERN SO CONFIDENCE IS A BIT HIGHER THAN WITH
SOME OF THE FORECASTS DURING THE PAST COUPLE OF DAYS.
ONCE AGAIN THE MORE NUMEROUS SHOWERS AND RESULTING CLOUDS ACROSS THE
NATURE COAST SHOULD HOLD HIGH TEMPERATURES DOWN IN THE 80S FOR THE
NATURE COAST WHILE AREAS ALONG AND SOUTH OF I-4 SEE LOWER TO MIDDLE
90S.
&&
.LONG TERM (TUESDAY NIGHT-MONDAY)...
MODEL SOLUTIONS ARE IN GOOD AGREEMENT SHOWING A LONG WAVE UPPER
TROUGH OVER THE WESTERN GREAT LAKES STATES TUESDAY NIGHT AND
WEDNESDAY...DEEPENING AND CLOSING OFF AS IT SHIFTS INTO NORTHERN NEW
ENGLAND AND SOUTHERN QUEBEC BY THE END OF THE WORK WEEK. THE FEATURE
WILL THEN LIFT NORTHEASTWARD AND INTO THE CANADIAN MARITIMES OVER
THE UPCOMING WEEKEND. AT THE SURFACE...THIS WILL DRIVE A FRONTAL
BOUNDARY SOUTHWARD INTO NORTH FLORIDA WHERE IT WILL STALL OUT
THROUGH MUCH OF THE WORK WEEK BEFORE DISSIPATING OVER THE UPCOMING
WEEKEND. THIS WILL ALSO KEEP THE SURFACE HIGH PRESSURE RIDGE AXIS
SUPPRESSED ACROSS THE FLORIDA STRAIGHTS AND SOUTH FLORIDA THROUGH
THE WORK WEEK. THE RIDGE AXIS SHOULD THEN LIFT BACK NORTHWARD INTO
CENTRAL FLORIDA OVER THE UPCOMING WEEKEND AS UPPER LEVEL HEIGHTS
BEGIN TO BUILD OVER THE PENINSULA. OVERALL...EXPECT FAIRLY TYPICAL
SUMMER WEATHER UNDER SOUTHWESTERLY BOUNDARY LAYER FLOW THROUGH THE
PERIOD WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY. THE
SHOWERS AND STORMS WILL DEVELOP EACH NIGHT OVER THE EASTERN GULF AND
DRIFT INTO COASTAL ZONES PRIOR TO DAYBREAK. THE ACTIVITY WILL THEN
TRANSITION INLAND AND INCREASE IN COVERAGE AND INTENSITY DURING THE
AFTERNOON. TEMPERATURES ARE EXPECTED TO RUN NEAR NORMAL THROUGH THE
LONG TERM PERIOD.
&&
.AVIATION...
MAJORITY OF THE RAIN WILL REMAIN TO THE NORTH OF THE I-4 CORRIDOR
INTO THE EARLY EVENING...ALTHOUGH A BRIEF SHOWER OR 2 WILL STILL BE
POSSIBLE AT KTPA/KPIE/KLAL. LOOKING FOR A LET UP IN THE SHOWERS
ACROSS THE NORTH LATER TODAY AND WILL REMOVE SHOWER MENTION FROM THE
ALL TAFS FOR THE OVERNIGHT. ANOTHER ROUND OF SHOWERS SHOULD DEVELOP
LATE TONIGHT INTO TUESDAY MORNING OVER THE NATURE COAST WITH
KTPA/KPIE/KLAL RESIDING ON THE SOUTHERN EDGE OF THIS THREAT AREA.
WILL ADD VCSH BACK INTO THESE NORTHERN TERMINALS AFTER SUNRISE ON
TUESDAY. AWAY FROM ANY SHOWERS...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
INTERACTION BETWEEN A FRONTAL BOUNDARY OVER NORTHERN FLORIDA AND THE
SUBTROPICAL RIDGE AXIS ACROSS SOUTHERN FLORIDA WILL KEEP WEST TO
SOUTHWEST FLOW IN PLACE FOR THE NEXT SEVERAL DAYS. THE FLOW WILL BE
A BIT STRONGER TODAY...AROUND 15 KNOTS FOR THE OFFSHORE WATERS
ADJACENT TO THE NATURE COAST. NO HEADLINES ARE EXPECTED OTHERWISE
AND SEAS WILL REMAIN 3 FEET OR LESS. SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED THIS MORNING OVER THE GULF AND NEAR SHORE WATERS...
ESPECIALLY NORTH OF TAMPA BAY. THIS ACTIVITY WILL CONTINUE
THROUGHOUT THE WEEK. MAIN HAZARDS WILL BE SCATTERED
THUNDERSTORMS...DANGEROUS LIGHTNING...AND LOCALIZED GUSTY WINDS IN
AND NEAR THUNDERSTORMS.
&&
.FIRE WEATHER...
RAIN CHANCES WILL REMAIN HIGHEST ALONG THE NATURE COAST TONIGHT AND
INTO TUESDAY. FROM TAMPA BAY SOUTHWARD...AFTERNOON SHOWERS AND
STORMS CAN BE EXPECTED FOR AREAS AWAY FROM THE IMMEDIATE COAST.
OTHERWISE...NO SIGNIFICANT FIRE WEATHER CONCERNS AS RELATIVE
HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS THROUGH THE
MIDDLE OF THE WEEK.
FOG POTENTIAL...ISOLATED POCKETS OF SHALLOW PATCHY GROUND FOG
WILL BE POSSIBLE IN OPEN FIELDS EACH MORNING...BUT SIGNIFICANT
VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 91 79 92 / 30 40 30 30
FMY 77 93 77 93 / 10 20 20 20
GIF 75 94 76 94 / 30 30 10 30
SRQ 79 89 78 92 / 10 20 20 20
BKV 74 89 73 93 / 40 60 30 40
SPG 80 90 80 91 / 30 30 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 10 PM EDT THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION...MROCZKA
MARINE...WYNN
FIRE WEATHER...MCKAUGHAN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
527 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL DISTURBANCE EARLY THIS
EVENING. WINDOW OF OPPORTUNITY SHOULD BE RELATIVELY SHORT.
* ANOTHER CHANCE FOR SHRA/TSRA WITH A COLD FRONT PASSAGE
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH IN SHRA CHANCES EARLY THIS EVENING...LOW IN TIMING AND
DURATION OF IMPACTS AT TERMINALS.
* MEDIUM ON TIMING OF PCPN WITH THE COLD FRONT OVERNIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
406 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
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
313 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
&&
$$
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
258 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS GRADUALLY IMPROVING FROM MVFR TO VFR BY EARLY AFTERNOON.
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM ON TIMING OF CIGS LIFTING THIS AFTERNOON.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
&&
$$
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
117 PM CDT MON AUG 11 2014
.DISCUSSION...
1131 AM CDT
FOR MORNING UPDATE...
HAVE MADE SOME TWEAKS TO POPS/WX/SKY COVER THROUGH EARLY AFTERNOON
BASED ON CURRENT TRENDS.
INITIAL MID-LEVEL VORT MOVING EAST OF AREA LATE THIS MORNING
WHICH HAS ALLOWED PRECIP TO TAPER OFF TO JUST A FEW ISOLATED
SHOWERS MAINLY ACROSS THE ILLINOIS/INDIANA STATE LINE REGION AS OF
1130 AM CDT. GOES VISIBLE SATELLITE IMAGERY SHOWS AN AREA OF
CLEARING SKIES OVER MUCH OF WESTERN AND CENTRAL IL...WHICH WILL
WORK EAST ACROSS THE CWA OVER THE NEXT FEW HOURS. THIS SHOULD ALLOW
FOR SOME DESTABILIZATION WITHIN THE LOW LEVEL AIR MASS...WITH
WARMING TO AROUND 80 DEGREES WITH LOW-MID 60S SURFACE DEW POINT
TEMPS EXPECTED TO YIELD 500-1000 J/KG OF MLCAPE BY LATER THIS
AFTERNOON. SOME CONVECTIVE SHOWER/ISOLATED THUNDERSTORM
DEVELOPMENT IS EXPECTED AS SURFACE COLD FRONT MOVES INTO THE AREA
FROM SOUTHWEST WI/EASTERN IA AND ANOTHER MID-LEVEL SHORT WAVE DIGS
ACROSS THE AREA DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
WEAK DEEP LAYER BULK SHEAR...AND LOW LEVEL WEST-NORTHWEST AHEAD OF
THE SURFACE COLD FRONT SHOULD LIMIT OVERALL THUNDERSTORM INTENSITY
ALTHOUGH SLOW MOVING CELLS MAY STILL BE A THREAT TO PRODUCE SOME
LOCALLY HEAVY DOWNPOURS GIVEN PRECIPITABLE WATER VALUES STILL IN
THE 1.25-1.50 INCH RANGE. SHOWER/ISOLATED THUNDER POTENTIAL WILL
CONTINUE TONIGHT ESPECIALLY OVER NORTHEAST IL/LAKE
MICHIGAN/NORTHWEST INDIANA AS MID-LEVEL VORT MOVES SOUTHEAST
ACROSS THE REGION.
RATZER
//PREV DISCUSSION...
255 AM CDT
TODAY THROUGH TONIGHT...
IR IMAGERY INDICATES CONSIDERABLE CLOUDINESS ACROSS THE REGION EARLY
THIS MORNING. ANALYSIS INDICATES A MID-LVL WAVE SLIDING EAST
OVERHEAD THIS MORNING. THE COMBINATION OF THE UPPER LEVEL SYSTEM AND
CONSIDERABLE LLVL MOISTURE HAS ALLOWED AN AREA OF SHOWERS W/ISO
THUNDER THIS MORNING. THIS GENERALLY HAS BEEN FOCUSED ACROSS FAR
NORTHEAST IL. WITH THE PWAT VALUES HOVERING NEAR 1.7"...ANY SHOWER
ACTIVITY COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS. SOME OF THE
INSTANTANEOUS RATES HAVE HOVERED AROUND 4"/HR...FORTUNATELY THIS IS
ONLY LASTING FOR 10-15 MINS.
SPOTTY SHOWERS AND THUNDERSTORMS WILL CONTINUE THRU THIS MORNING AS
THE SHORTWAVE/TROUGH AXIS CONTINUES TO PIVOT EAST OVERHEAD. LLVL
MOISTURE CONVERGENCE WILL PERSIST...AND WITH THE HIGH DEW PTS/PWAT
VALUES...ANY SHOWERS COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS.
INSTABILITY WILL BE ELEVATED...SO HAVE HELD ONTO MENTION OF
THUNDERSTORMS. 850MB LOW WILL SLIGHTLY STRENGTHEN OVER THE OHIO
VALLEY AS IT ROTATES NORTHEAST ACROSS NORTHWEST OHIO THIS AFTN.
SFC WINDS WILL BE LIGHT TO VARIABLE TO START THE DAY...THEN BEGIN TO
SOLIDIFY FROM THE NORTHWEST. GIVEN THE CONSIDERABLE SOLAR
SHIELDING...EXPECT TEMPS TO STRUGGLE TO WARM TODAY. SO HAVE NUDGED
TEMPS DOWN A COUPLE OF DEGREES...INTO THE UPR 70S FOR THE NORTHEAST
CWFA AND ARND 80 IN OUR WESTERN FORECAST AREAS.
FOR THIS EVENING THE STRONGER TROUGH AXIS WILL BE APPROACHING THE
GREAT LAKES FROM THE NORTHWEST. LLVL MOISTURE WILL REMAIN ABUNDANT
OVER MUCH OF THE FORECAST AREA...SLOWLY PIVOTING TO THE EAST
OVERNIGHT INTO TUE MORNING. HAVE NUDGED POPS UP TOWARDS
LIKELY...MAINLY FOCUSED FOR THE NORTH/NORTHEAST CWFA. TEMPS ALOFT
WILL BE STEADILY COOLING...BUT EXPECT OVERNIGHT LOWS TO ONLY DROP
INTO THE LOW 60S TO MID 60S NEAR DOWNTOWN CHICAGO.
TUESDAY...
500MB VORT MAX WILL BE SLIDING SOUTHEAST ACROSS SOUTHEAST WISC
TOWARDS NORTHERN IN BY MIDDAY TUE. THIS IS SLIGHTLY FURTHER SOUTH
THEN PRIOR CYCLES...AND LOCAL ARW8KM SOLUTION INDICATES A FEW WEAKER
LOBES OF VORTICITY WILL ROTATE AROUND THE WESTERN PERIPHERY WITH
REINFORCING SLUGS OF PRECIP THRU MIDDAY TUE BEFORE DEPARTING TO THE
EAST AS ANTI-CYCLONIC FLOW STEADILY ERODES LLVL MOISTURE TUE EVE.
THERMAL TROUGH AT 850MB WILL SLOWLY SLIDE SOUTH ACROSS THE
REGION...GENERALLY BETWEEN 8-10 DEG C FOR MUCH OF THE FORECAST AREA.
THE STEADY NORTHERLY FLOW WILL LIKELY HOLD TEMPS IN THE LOW 70S FOR
MUCH OF THE CWFA. THE EXCEPTION COULD BE THE FAR WEST/SOUTHWEST
WHERE TEMPS COULD PUSH TO THE MID 70S. SFC RIDGING WILL WEAKEN THE
GRADIENT TUE NGT...WITH SKIES TRYING TO THIN. THIS WILL ALLOW TEMPS
TO RADIATE INTO THE LOW 50S...POSSIBLY UPR 40S IN THE MORE
TRADITIONAL COOL SPOTS TUE NGT. MEANWHILE AREAS ADJACENT TO LAKE
MICHIGAN WILL SEE TEMPS HOLD IN THE UPR 50S/LOW 60S.
WEDNESDAY THROUGH FRIDAY...
SFC RIDGE WILL BE IN CONTROL FOR MID-WEEK THRU FRI...LIKELY KEEPING
DRY AND PLEASANT CONDITIONS ACROSS THE REGION. LOCAL ARW8KM DOES
PAINT A WEAK LOBE OF VORTICITY TRYING TO SLIDE SOUTHEAST ACROSS THE
GREAT LAKES WED...HOWEVER FEEL MAINTAINING DRY CONDS IS THE MOST
PROBABLE OUTCOME FOR WED THRU FRI.
500MB VORT WILL BECOME QUASI-STATIONARY OVER SOUTHEAST ONTARIO WITH
HIGH AMPLITUDE RIDGING OVER THE CANADIAN ROCKIES KEEPING THE WESTERN
GREAT LAKES IN A NORTHWEST FLOW PATTERN.
TEMPS WILL GENERALLY BE IN THE UPR 70S...WITH A FEW SITES HITTING 80
OR ARND 80 BY THUR/FRI.
SATURDAY THROUGH SUNDAY...
ENSEMBLES HAVE CONTINUED MINIMAL SPREAD THRU SAT...HOWEVER BEYOND
THIS POINT THE SPREAD DRAMATICALLY INCREASES. ONE OF THE PROBLEMS
SOLUTIONS ARE STRUGGLING WITH IS TRYING TO WEAKEN THE DOWNSTREAM
BLOCK OF THE NORTH ATLANTIC...WHICH WILL HAVE AN IMPACT ON THE
TROUGH OVER SOUTHERN ONTARIO AND THE NORTHWEST FLOW FOR THE GREAT
LAKES. THERE IS SOME AGREEMENT THAT THE FLOW OVER THE GREAT
LAKES/UPPER MIDWEST WILL BEGIN TO FLATTEN AND TRANSITION TOWARDS A
SEMI-ZONAL PATTERN FOR THE WEEKEND...WHICH WILL BRING A SOMEWHAT
ACTIVE SETUP TO THE AREA. SO HAVE CHC POPS RETURNING LATE FRI THRU
SUN. TEMPS WILL BE SLOWLY RETURNING TO SEASONAL CONDITIONS OR IN THE
LOW 80S.
CONFIDENCE...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS GRADUALLY IMPROVING FROM MVFR TO VFR BY EARLY AFTERNOON.
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM ON TIMING OF CIGS LIFTING THIS AFTERNOON.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 PM MONDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
MONDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1256 PM CDT Mon Aug 11 2014
.UPDATE...
ISSUED AT 1000 AM CDT MON AUG 11 2014
Morning surface analysis shows low pressure centered over north-
central Indiana, with bulk of associated precip well to the E/NE
of the KILX CWA over northern Indiana/southern Michigan. Further
west in Illinois, only isolated showers persist along the I-57
corridor. As low moves further away and short-wave subsidence
develops behind departing upper wave, think conditions will be
mostly dry for the balance of the morning into the early
afternoon. Cold front currently across central Iowa will push
eastward later today, perhaps enhancing precip chances by mid to
late afternoon. While front will be encountering a moist airmass
with CAPE vales projected to be around 1500J/kg, poor convergence
along the boundary and extremely weak bulk shear will keep
convective development to a minimum. Both the 12z NAM and the
latest HRRR show only widely scattered showers/thunder developing
along the front across the Illinois River Valley after 1 PM, then
spreading eastward to the I-55 corridor by 4 to 5 PM. Will
therefore only carry 20-30 PoPs today into the early evening,
before ending precip chances entirely after midnight. Made a few
adjustments to PoPs and sky cover today, but temps appear to be
right on track so far.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Patchy showers, with an occasional lightning strike evident,
continue to push slowly east across west-central Illinois early this
morning. These showers are ahead of an impulse that is quite
noticeable on water vapor imagery. A more widespread area of
showers/storms lies across northeast Illinois, associated with some
low-mid level convergence and weak WAA ahead of the above mentioned
impulse. Meanwhile, a cold front extends southwest into the upper
Midwest from northern Ontario. This front is being driven by a
couple upper level waves, and will eventually clear the forecast
area to the east by this evening.
High-resolution models suggest the west-central Illinois showers
should continue east for a time, but eventually weaken. Have my
doubts that this will occur as progged, as this feature will
eventually have diurnal instability to work with. Do not expect
severe storms today given weak shear profiles (bulk shear generally
20 kts or below), but peak diurnal instability should approach 1500
j/kg over most of the forecast area. This instability and the
available forcing should be able to produce scattered thunderstorms
across most of the forecast area today. The best coverage is expected
in the east, where the forcing from the west-central Illinois wave
and peak heating will co-exist for the longest period of time.
However, can`t rule out additional development until early evening
when the surface cold front and main upper wave pass east of the
area. Lingering cloud cover, as well as shower/storm threat, should
keep high temperatures today similar to the past two, generally in
the lower 80s.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Strong upper level trof will be over the Ohio river valley Tue as
surface low pressure ejects ne to along the Quebec/Ontario province
line by sunset Tuesday. A few showers could occur over ne CWA Tue
while most of central IL should be dry Tue as skies become mostly
sunny Tue afternoon. Northwest breezes to bring in cooler and less
humid air as dewpoints slip into the upper 50s and lower 60s by days
end. Highs 75-80F on Tuesday with warmest readings by Lawrenceville.
Skies clear and nw winds diminish light by overnight Tuesday night
with cooler lows in the mid 50s. Upper level trof pulling away from
IL on Wed while 1021 mb Canadian high pressure settling into the
Midwest and keeps cooler and drier air in place through Thu night.
Highs Wed mostly in the upper 70s with lows Wed night in the upper
50s. Highs Thu in the lower 80s and dewpoints easing up into the
lower 60s Thu afternoon as surface ridge drifts east across IL.
Extended models diverge late this week and the models overall have
trended slower with arrival of next weather system late this week.
Most models are now drier on Friday over central/se IL with surface
high pressure ridge drifting slowly east into IN/OH/KY. Have lowered
pops Friday with eastern IL staying dry Friday, and having 20-30%
chance by Friday afternoon over western areas. Stayed close to
AllBlend during the extended forecast this weekend into early next
week which brings chances of showers and thunderstorms across the
area Friday night and Saturday with an approaching warm front from
the southwest. Warmer and more humid air to return to IL this
weekend as dewpoints elevate into the upper 60s and lower 70s. Upper
level ridge over IL by Sunday and this appears to be the warmest day
with highs in the mid to upper 80s. Main storm track to shift north
of central IL early next week and just have slight chances of
showers and thunderstorms Sunday-Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1256 PM CDT MON AUG 11 2014
Cold front currently along the Mississippi River will push
eastward this afternoon. A few radar returns are beginning to
develop along the boundary, but the latest HRRR continues to
suggest this activity will remain widely scattered in nature. Have
therefore included VCSH at the terminals ending by 00z at KPIA and
by around 02z further east at KCMI. Big question will be how much
cloud cover filters into the region behind the departing front
tonight into Tuesday. 1730z satellite imagery shows a large mass
of MVFR clouds dropping southeastward across northern/central
Iowa. Based on trajectories, these clouds should spill across
central Illinois this evening. NAM forecast soundings support this
theory: however, GFS is not nearly as aggressive. Based mainly
upon current upstream obs, have decided to be pessimistic with the
aviation forecast and include MVFR ceilings across the board
between 02z and 18z. Later forecasts may be fine-tuned if cloud
cover begins to erode after sunset or takes a more northerly
track.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...BAK
LONG TERM...07
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1114 AM CDT MON AUG 11 2014
.DISCUSSION...
255 AM CDT
TODAY THROUGH TONIGHT...
IR IMAGERY INDICATES CONSIDERABLE CLOUDINESS ACROSS THE REGION EARLY
THIS MORNING. ANALYSIS INDICATES A MID-LVL WAVE SLIDING EAST
OVERHEAD THIS MORNING. THE COMBINATION OF THE UPPER LEVEL SYSTEM AND
CONSIDERABLE LLVL MOISTURE HAS ALLOWED AN AREA OF SHOWERS W/ISO
THUNDER THIS MORNING. THIS GENERALLY HAS BEEN FOCUSED ACROSS FAR
NORTHEAST IL. WITH THE PWAT VALUES HOVERING NEAR 1.7"...ANY SHOWER
ACTIVITY COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS. SOME OF THE
INSTANTANEOUS RATES HAVE HOVERED AROUND 4"/HR...FORTUNATELY THIS IS
ONLY LASTING FOR 10-15 MINS.
SPOTTY SHOWERS AND THUNDERSTORMS WILL CONTINUE THRU THIS MORNING AS
THE SHORTWAVE/TROUGH AXIS CONTINUES TO PIVOT EAST OVERHEAD. LLVL
MOISTURE CONVERGENCE WILL PERSIST...AND WITH THE HIGH DEW PTS/PWAT
VALUES...ANY SHOWERS COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS.
INSTABILITY WILL BE ELEVATED...SO HAVE HELD ONTO MENTION OF
THUNDERSTORMS. 850MB LOW WILL SLIGHTLY STRENGTHEN OVER THE OHIO
VALLEY AS IT ROTATES NORTHEAST ACROSS NORTHWEST OHIO THIS AFTN.
SFC WINDS WILL BE LIGHT TO VARIABLE TO START THE DAY...THEN BEGIN TO
SOLIDIFY FROM THE NORTHWEST. GIVEN THE CONSIDERABLE SOLAR
SHIELDING...EXPECT TEMPS TO STRUGGLE TO WARM TODAY. SO HAVE NUDGED
TEMPS DOWN A COUPLE OF DEGREES...INTO THE UPR 70S FOR THE NORTHEAST
CWFA AND ARND 80 IN OUR WESTERN FORECAST AREAS.
FOR THIS EVENING THE STRONGER TROUGH AXIS WILL BE APPROACHING THE
GREAT LAKES FROM THE NORTHWEST. LLVL MOISTURE WILL REMAIN ABUNDANT
OVER MUCH OF THE FORECAST AREA...SLOWLY PIVOTING TO THE EAST
OVERNIGHT INTO TUE MORNING. HAVE NUDGED POPS UP TOWARDS
LIKELY...MAINLY FOCUSED FOR THE NORTH/NORTHEAST CWFA. TEMPS ALOFT
WILL BE STEADILY COOLING...BUT EXPECT OVERNIGHT LOWS TO ONLY DROP
INTO THE LOW 60S TO MID 60S NEAR DOWNTOWN CHICAGO.
TUESDAY...
500MB VORT MAX WILL BE SLIDING SOUTHEAST ACROSS SOUTHEAST WISC
TOWARDS NORTHERN IN BY MIDDAY TUE. THIS IS SLIGHTLY FURTHER SOUTH
THEN PRIOR CYCLES...AND LOCAL ARW8KM SOLUTION INDICATES A FEW WEAKER
LOBES OF VORTICITY WILL ROTATE AROUND THE WESTERN PERIPHERY WITH
REINFORCING SLUGS OF PRECIP THRU MIDDAY TUE BEFORE DEPARTING TO THE
EAST AS ANTI-CYCLONIC FLOW STEADILY ERODES LLVL MOISTURE TUE EVE.
THERMAL TROUGH AT 850MB WILL SLOWLY SLIDE SOUTH ACROSS THE
REGION...GENERALLY BETWEEN 8-10 DEG C FOR MUCH OF THE FORECAST AREA.
THE STEADY NORTHERLY FLOW WILL LIKELY HOLD TEMPS IN THE LOW 70S FOR
MUCH OF THE CWFA. THE EXCEPTION COULD BE THE FAR WEST/SOUTHWEST
WHERE TEMPS COULD PUSH TO THE MID 70S. SFC RIDGING WILL WEAKEN THE
GRADIENT TUE NGT...WITH SKIES TRYING TO THIN. THIS WILL ALLOW TEMPS
TO RADIATE INTO THE LOW 50S...POSSIBLY UPR 40S IN THE MORE
TRADITIONAL COOL SPOTS TUE NGT. MEANWHILE AREAS ADJACENT TO LAKE
MICHIGAN WILL SEE TEMPS HOLD IN THE UPR 50S/LOW 60S.
WEDNESDAY THROUGH FRIDAY...
SFC RIDGE WILL BE IN CONTROL FOR MID-WEEK THRU FRI...LIKELY KEEPING
DRY AND PLEASANT CONDITIONS ACROSS THE REGION. LOCAL ARW8KM DOES
PAINT A WEAK LOBE OF VORTICITY TRYING TO SLIDE SOUTHEAST ACROSS THE
GREAT LAKES WED...HOWEVER FEEL MAINTAINING DRY CONDS IS THE MOST
PROBABLE OUTCOME FOR WED THRU FRI.
500MB VORT WILL BECOME QUASI-STATIONARY OVER SOUTHEAST ONTARIO WITH
HIGH AMPLITUDE RIDGING OVER THE CANADIAN ROCKIES KEEPING THE WESTERN
GREAT LAKES IN A NORTHWEST FLOW PATTERN.
TEMPS WILL GENERALLY BE IN THE UPR 70S...WITH A FEW SITES HITTING 80
OR ARND 80 BY THUR/FRI.
SATURDAY THROUGH SUNDAY...
ENSEMBLES HAVE CONTINUED MINIMAL SPREAD THRU SAT...HOWEVER BEYOND
THIS POINT THE SPREAD DRAMATICALLY INCREASES. ONE OF THE PROBLEMS
SOLUTIONS ARE STRUGGLING WITH IS TRYING TO WEAKEN THE DOWNSTREAM
BLOCK OF THE NORTH ATLANTIC...WHICH WILL HAVE AN IMPACT ON THE
TROUGH OVER SOUTHERN ONTARIO AND THE NORTHWEST FLOW FOR THE GREAT
LAKES. THERE IS SOME AGREEMENT THAT THE FLOW OVER THE GREAT
LAKES/UPPER MIDWEST WILL BEGIN TO FLATTEN AND TRANSITION TOWARDS A
SEMI-ZONAL PATTERN FOR THE WEEKEND...WHICH WILL BRING A SOMEWHAT
ACTIVE SETUP TO THE AREA. SO HAVE CHC POPS RETURNING LATE FRI THRU
SUN. TEMPS WILL BE SLOWLY RETURNING TO SEASONAL CONDITIONS OR IN THE
LOW 80S.
CONFIDENCE...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS GRADUALLY LIFTING THIS MORNING
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY
ED F
//DISCUSSION...UPDATED 12Z...
AN UPPER LEVEL DISTURBANCE IS PASSING THROUGH THE AREA THIS
MORNING AND IS DRIVING THE MAIN AREA OF -RA/TS INTO FAR NE IL AND
INTO NW IN. NOT EXPECTING ANY FURTHER TS THIS MORNING AT THE
CHICAGO TERMINALS OTHER THAN EAST OF A LINE FROM LANSING TO
KANKAKEE. LIGHTER WINDS AND MOIST LOW LEVELS WILL MEAN A PERIOD OF
MVFR/IFR VSBYS AND OR CIGS. AN UPPER LEVEL TROUGH WILL APPROACH
FROM THE NW LATER THIS AFTERNOON. ADDITIONALLY...A LAKE BREEZE IS
EXPECTED TO FORM. BOTH OF THESE BRING THE THE POTENTIAL FOR
ADDITIONAL SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...AND THEN AGAIN WITH THE COLD FRONTAL PASSAGE LATE
TONIGHT. EXPECT A PERIOD OF MVFR/IFR CONDITIONS BEHIND THE FRONT
AND GUSTY NW WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* LOW TO MEDIUM ON TIMING OF CIGS LIFTING THIS MORNING.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON... LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY... WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT LEAST MVFR CIGS BEHIND THE FRONT LATE
TONIGHT...POSSIBLY LOWER.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 PM MONDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
MONDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1000 AM CDT Mon Aug 11 2014
.UPDATE...
ISSUED AT 1000 AM CDT MON AUG 11 2014
Morning surface analysis shows low pressure centered over
north-central Indiana, with bulk of associated precip well to the
E/NE of the KILX CWA over northern Indiana/southern Michigan.
Further west in Illinois, only isolated showers persist along the
I-57 corridor. As low moves further away and short-wave subsidence
develops behind departing upper wave, think conditions will be
mostly dry for the balance of the morning into the early
afternoon. Cold front currently across central Iowa will push
eastward later today, perhaps enhancing precip chances by mid to
late afternoon. While front will be encountering a moist airmass
with CAPE vales projected to be around 1500J/kg, poor convergence
along the boundary and extremely weak bulk shear will keep
convective development to a minimum. Both the 12z NAM and the
latest HRRR show only widely scattered showers/thunder developing
along the front across the Illinois River Valley after 1 PM, then
spreading eastward to the I-55 corridor by 4 to 5 PM. Will
therefore only carry 20-30 PoPs today into the early evening,
before ending precip chances entirely after midnight. Made a few
adjustments to PoPs and sky cover today, but temps appear to be
right on track so far.
&&
.SHORT TERM...(This afternoon through Tuesday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Patchy showers, with an occasional lightning strike evident,
continue to push slowly east across west-central Illinois early this
morning. These showers are ahead of an impulse that is quite
noticeable on water vapor imagery. A more widespread area of
showers/storms lies across northeast Illinois, associated with some
low-mid level convergence and weak WAA ahead of the above mentioned
impulse. Meanwhile, a cold front extends southwest into the upper
Midwest from northern Ontario. This front is being driven by a
couple upper level waves, and will eventually clear the forecast
area to the east by this evening.
High-resolution models suggest the west-central Illinois showers
should continue east for a time, but eventually weaken. Have my
doubts that this will occur as progged, as this feature will
eventually have diurnal instability to work with. Do not expect
severe storms today given weak shear profiles (bulk shear generally
20 kts or below), but peak diurnal instability should approach 1500
j/kg over most of the forecast area. This instability and the
available forcing should be able to produce scattered thunderstorms
across most of the forecast area today. The best coverage is expected
in the east, where the forcing from the west-central Illinois wave
and peak heating will co-exist for the longest period of time.
However, can`t rule out additional development until early evening
when the surface cold front and main upper wave pass east of the
area. Lingering cloud cover, as well as shower/storm threat, should
keep high temperatures today similar to the past two, generally in
the lower 80s.
&&
.LONG TERM...(Tuesday night through Sunday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Strong upper level trof will be over the Ohio river valley Tue as
surface low pressure ejects ne to along the Quebec/Ontario province
line by sunset Tuesday. A few showers could occur over ne CWA Tue
while most of central IL should be dry Tue as skies become mostly
sunny Tue afternoon. Northwest breezes to bring in cooler and less
humid air as dewpoints slip into the upper 50s and lower 60s by days
end. Highs 75-80F on Tuesday with warmest readings by Lawrenceville.
Skies clear and nw winds diminish light by overnight Tuesday night
with cooler lows in the mid 50s. Upper level trof pulling away from
IL on Wed while 1021 mb Canadian high pressure settling into the
Midwest and keeps cooler and drier air in place through Thu night.
Highs Wed mostly in the upper 70s with lows Wed night in the upper
50s. Highs Thu in the lower 80s and dewpoints easing up into the
lower 60s Thu afternoon as surface ridge drifts east across IL.
Extended models diverge late this week and the models overall have
trended slower with arrival of next weather system late this week.
Most models are now drier on Friday over central/se IL with surface
high pressure ridge drifting slowly east into IN/OH/KY. Have lowered
pops Friday with eastern IL staying dry Friday, and having 20-30%
chance by Friday afternoon over western areas. Stayed close to
AllBlend during the extended forecast this weekend into early next
week which brings chances of showers and thunderstorms across the
area Friday night and Saturday with an approaching warm front from
the southwest. Warmer and more humid air to return to IL this
weekend as dewpoints elevate into the upper 60s and lower 70s. Upper
level ridge over IL by Sunday and this appears to be the warmest day
with highs in the mid to upper 80s. Main storm track to shift north
of central IL early next week and just have slight chances of
showers and thunderstorms Sunday-Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 654 AM CDT MON AUG 11 2014
MVFR/IFR conditions across the central Illinois terminals to start
the day, with scattered showers and isolated thunderstorms in the
vicinity. Covered this precipitation with a few hour tempo for
showers at all locations. Then, a break is expected in the
precipitation, with conditions improving to VFR by mid-late
morning. A few showers/storms may return by late afternoon ahead
of a weak cold front, but coverage and timing certainty is too low
to go above a VCSH mention. Rain chances will end tonight, but
cigs/vsbys are likely to return to MVFR (or lower) behind the
front overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...BARNES
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
124 PM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 1102 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION TODAY INTO
TONIGHT AND AN UPPER LEVEL TROUGH WILL MOVE THROUGH TONIGHT INTO
TOMORROW. THESE TWO WILL CAUSE PERIODS OF SHOWERS AND
THUNDERSTORMS THROUGH TOMORROW. HIGH TEMPERATURES WILL RANGE FROM
THE MIDDLE 70S IN THE NORTH TO THE UPPER 70S NEAR THE OHIO RIVER.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE UPPER 60S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM EDT MON AUG 11 2014
POTENT PV ANOMALY WORKING EWD THROUGH CNTRL IN YIELDING AN ABUNDANCE
OF SHRA/TSRA FM NW OH SWWD THROUGH CNTRL IN. HWVR BACK EDGE OF
WIDESPREAD RAIN SHIELD WILL CONT TO WORK ENE THROUGH THE REMAINDER
OF THIS AFTN AND XPC MAINLY DRY CONDS TO PREVAIL IN WAKE OF THIS SYS
AS DEEP LYRD SUBSIDENCE ENSUES.
OTRWS STG UPSTREAM SW TROUGH ACRS MN WILL DIG SEWD TONIGHT AND
BOTTOM ACRS SRN MI. MIXED MODEL SIGNALS SPELL CONSIDERABLE
UNCERTAINTY THROUGH SRN PERIPHERY OF H7-5 MID LVL TROUGH ALTHOUGH
SOME THETA-E RTN IS INDICATED AT H85 AFT MIDNIGHT TONIGHT WHICH MAY
FOSTER REDVLPMNT OF SHRA ACRS NW ZONES INCLUDING KSBN TERMINAL TWD
12Z YET NOT SOLD ENOUGH ON THE IDEA YET TO INCLUDE IN 18Z FCST. BTR
CHCS LOOK TO MATERIALIZE TWD 18Z AT KFWA W/MUCH BTR DIURNAL TIMING
INDICATED AND CLOSER PROXIMITY TO LL THETA-E RTN RIDGE AHD OF MID
LVL TROUGH AXIS. ALTHOUGH HERE TOO KEPT W/DRY FCST ATTM GIVEN LT PD
TIMING AND GENERAL HIGH SPREAD IN MODEL TIMING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 4 PM CDT THIS AFTERNOON FOR INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 5 PM EDT THIS AFTERNOON FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...T
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1048 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 526 AM MDT MON AUG 11 2014
ADDED MENTION OF PATCHY FOG TO NORTHERN PART OF CWA BASED ON
CURRENT OBS ALONG REPUBLICAN RIVER VALLEY. CURRENTLY NOT REALLY
CONFIDENT ON EXTENT OF FOG...SO KEPT COVERAGE/MENTION IN LINE WITH
LATEST SHORT RANGE GUIDANCE/OBS WITH DISSIPATION EXPECTED BY MID
MORNING WHEN DAYTIME HEATING WILL ERODE FOG.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1047 AM MDT MON AUG 11 2014
A BAND OF CUMULUS CLOUDS DEVELOPED ACROSS SOUTHWEST NEBRASKA...SO
INCLUDED SCATTERED CLOUDS AT KMCK THROUGH THE AFTERNOON. ALTHOUGH
THE AIR MASS WILL BE UNSTABLE ENOUGH TO SUPPORT CONVECTION OVER
SOUTHWEST NEBRASKA THIS AFTERNOON...THE CHANCE IS TOO LITTLE TO
INCLUDE IN TAF. THEREFORE...VFR CONDITIONS WILL CONTINUE AT KGLD
AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BRB
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS JACKSON KY
339 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 339 PM EDT MON AUG 11 2014
CURRENT CONDITIONS ACROSS THE REGION FEATURE AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING THROUGH THE AREA ALONG THE EASTERN COUNTIES
BORDERING VA. THIS ACTIVITY WAS TIED TO A POTENT UPPER LEVEL TROUGH
MOVING THROUGH. OUT WEST...THE ANOTHER PREFRONTAL TROUGH STILL NEEDS
TO SWING THROUGH THE AREA TONIGHT AND WILL DO SO AFTER 00Z TONIGHT.
ALONG AND AHEAD OF THE BOUNDARY...SOME SHOWERS AND STORMS WILL MOVE
BACK INTO EASTERN KENTUCKY THIS EVENING AND TONIGHT. THOUGH THIS WILL
NOT BE AS STRONG AS THE EARLIER AS THE CELLS EARLIER BUT...ADDITIONAL
RAINFALL MAY BE ENOUGH TO CAUSE SOME MINOR FLOODING OVER AREAS THAT
GOT RAIN EARLIER TODAY. EXPECT A LULL IN THE ACTIVITY LATER TONIGHT
AS MOST OF THE INSTABILITY WANES.
HEADING INTO TOMORROW...WITH THE COLD FRONT STILL TO PUSH
THROUGH AND WILL SWING THROUGH BY TUESDAY EVENING AND WILL ALLOW FOR
SOME THUNDERSTORM DEVELOPMENT TUESDAY AFTERNOON. WITH THE STRONGEST
SUPPORT BEING IN THE NORTH WITH THE TROUGH AXIS...THERE WILL BE A
BETTER CHANCE FOR STRONG TO POSSIBLY SEVERE THUNDERSTORM DEVELOPMENT.
MODEL SOUNDING WOULD SUGGEST TO THIS WITH AN ACTUAL DRY LAYER PUSHED
IN BEHIND THIS ANTICIPATED ACTIVITY. WILL HIGHLIGHT THIS THREAT IN
THE HWO AS WELL. MODELS HAVE BEEN AT LEAST REASONABLE WITH THIS SET
OVER THE PAST COUPLE OF DAYS AND ESPECIALLY THE NAM AND HRRR HAVE
BEEN VERIFYING REASONABLY.
FOR TUESDAY NIGHT...THE FRONT STANDS TO PUSH THE WHOLE WAY THROUGH
EASTERN KENTUCKY BY 06Z TUESDAY NIGHT. WITH SUBSIDENCE
OVERHEAD...CLEARING SKIES...AND COOLING TEMPS...DENSE FOG WILL BE AN
ISSUE COME TUESDAY NIGHT. IN FACT THE FOG COULD BE WIDE SPREAD. WILL
HIGHLIGHT THIS IN THE HWO AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 PM EDT MON AUG 11 2014
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY WITH A DEEP TROUGH
OVER THE EASTERN CONUS AND AN AMPLIFIED RIDGE OVER THE WESTERN CONUS.
DESPITE SOME SHIFTING IN THE UPPER LEVEL RIDGE OVER THE WEST...AN
OVERALL AMPLIFIED MERIDIONAL PATTERN WILL BE IN PLACE THROUGH THE
EXTENDED. THIS PATTERN IS A TAD BIT RARE FOR THIS TIME OF YEAR.
HOWEVER...BY THE LAST DAY OF THE EXTENDED. THE PATTERN HAS BROKEN
DOWN AS A SHORT WAVE TROUGH MOVES OVER THE RIDGE AND WEAKENS IT. THIS
WILL BRING THIS FEATURE OVER THE AREA BY THE END OF THE EXTENDED.
WITH THE GFS AND EURO SHOWING SOME DECENT AGREEMENT...LITTLE CHANGES
WERE NEEDED TO THE ALL MODEL BLEND SOLUTION.
FOR SOME DETAILS IN THE LOWER LEVELS...THE SURFACE COLD FRONT THAT
IMPACTED THE AREA INTO TUESDAY EVENING AND TUESDAY NIGHT...WILL PUSH
OFF TO THE EAST BRINGING SURFACE HIGH PRESSURE INTO THE AREA FOR
WEDNESDAY THROUGH SATURDAY KEEPING A PERIOD OF DRIER AND COOLER
WEATHER OVER EASTERN KENTUCKY. IN FACT...BEFORE TEMPERATURES MODERATE
INTO THE MID 80S ON SATURDAY...HIGH TEMPERATURES ON WEDNESDAY THROUGH
FRIDAY WILL BE 5 TO 7 DEGREES BELOW AVERAGE. IN SHORT...THE OVERALL
COOLER SUMMER CONTINUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 128 PM EDT MON AUG 11 2014
SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL BE THE
PRIMARY WEATHER ISSUE FOR THE AREA THROUGH THE TAF PERIOD AND AS
SUCH...ANY TAF SITE WITH HEAVY RAINFALL WILL DROP DOWN TO FIELD MINS
THIS AFTERNOON AND INTO THIS EVENING. HAVE SHOWN THIS IN THE TAFS.
LATER TONIGHT...WITH AREAS THAT HAVE RECEIVED RAINFALL...FOG AND LOW
CEILINGS WILL DEVELOP AND HAVE SHOWN THIS IN THE TAFS AS WELL. WINDS
WILL GENERALLY BE LIGHT EXCEPT IN AROUND THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...SHALLENBERGER
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
105 PM CDT MON AUG 11 2014
.AVIATION...
FOR THE 11/18Z TAFS...WEAK FRONTAL BOUNDARY TO CONTINUE SLOW SWRD
PROGRESS DURING THE TAF PERIOD. SCATTERED CONVECTION ALREADY SEEN
EARLY THIS AFTERNOON WITH GREATEST CONCENTRATION ACROSS THE EAST
AFFECTING THE ELD/MLU TERMINALS. FARTHER WEST...COVERAGE WILL STAY
MORE ISOLATED SO HAVE HANDLED REMAINING SITES WITH VCTS THROUGH
THIS AFTERNOON/EARLY EVENING. CONDITIONS ARE EXPECTED TO REMAIN
MOSTLY VFR WITH PERIODS OF MVFR CIGS/VSBYS POSSIBLE DURING HEAVY
DOWNPOURS. CLOUDS WILL GRADUALLY DECREASE FROM NORTH TO SOUTH
OVERNIGHT BEHIND THE FRONT WITH WINDS BECOMING MORE N/NW AND
SPEEDS LESS THAN 10 KTS OUTSIDE AREAS OF CONVECTION. /19/
&&
.PREV DISCUSSION... /ISSUED 1139 AM CDT MON AUG 11 2014/
DISCUSSION...
THE EARLY MORNING CONVECTION OVER SW AR HAS QUICKLY EXITED THE
REGION TO THE E INTO SE AR/EXTREME NE LA...WITH AN ATTENDANT
OUTFLOW BNDRY SHIFTING SE ACROSS SE UNION AND LINCOLN
PARISHES...WITH A 2ND BNDRY FARTHER TO THE SE ACROSS NE WINN/SRN
OUACHITA PARISHES. ISOLATED -SHRA HAVE DIMINISHED IN THE LAST HOUR
WITH VERY QUIET CONDITIONS IN PLACE ACROSS THE REMAINDER OF THE
REGION. THE 16Z SFC ANALYSIS INDICATED A WEAK SURFACE TROUGH
SITUATED W TO E ALONG THE I-20 CORRIDOR OF NCNTRL/NE TX/N
LA...ALTHOUGH THE SLIGHTLY DRY AIR LAGS THIS TROUGH A WAYS INTO SE
OK/NW AR. THE SHORT TERM PROGS SUGGEST THAT THIS SFC TROUGH WILL
NOT MOVE MUCH FARTHER S THIS AFTERNOON...UNLESS CONVECTIVELY
REINFORCED...GIVEN THE WEAK PRESSURE RISES TO THE N AND THE
SHALLOW NATURE OF THE FRONT. MEANWHILE...WATER VAPOR IMAGERY
DEPICTS A LONGWAVE TROUGH DIGGING SE THROUGH THE PLAINS THIS
MORNING...WITH THE UPPER TROUGH AXIS EXTENDING FROM NRN OK/SRN
MO...NE TO LAKE MI. SCT CONVECTION TO THE W JUST S OF THE RED
RIVER OF N TX THIS MORNING BEHIND THE SFC TROUGH CONTINUES TO
DIMINISH ATTM...WITH THE 06Z AND 12Z GFS NOT BULLISH AT ALL IN
CONVECTION DEVELOPING ONCE FURTHER DESTABILIZATION IS REALIZED
THIS AFTERNOON WITH ADDED HEATING. MEANWHILE...THE 12Z WRF AND
LATEST HRRR RUNS SUGGEST THAT SCT CONVECTION WILL DEVELOP AFTER 18Z
MAINLY ALONG/S OF THE I-20 CORRIDOR NEAR/S OF THE SFC
TROUGH...WHERE PW/S EXCEEDING 2.10 INCHES AND STRONG HEATING WILL
CONTRIBUTE TO STEEPER LOW LEVEL LAPSE RATES/3000+ J/KG MLCAPE.
HOWEVER...DEEP LAYER SHEAR AND FORCING SHOULD REMAIN WEAK...WITH
THE CONVECTION PRIMARILY OUTFLOW DRIVEN.
GIVEN THIS...HAVE TRIMMED BACK POPS TO CHANCE ACROSS MUCH OF E
TX/N LA...TAPERING TO SLIGHT CHANCE ACROSS EXTREME NE TX/FAR SRN
AR. HAVE DROPPED POPS FARTHER N ACROSS SE OK/NRN SECTIONS OF SW AR
GIVEN THE ABSENCE OF FRONTAL FORCING AND INTRUSION OF DEEP LEVEL DRIER
AIR. STILL CAN/T RULE OUT BRIEF HEAVY RAINFALL IN THE STRONGER
STORMS GIVEN THE HIGH PW/S AND VERY DEEP WARM LAYER INDICATED ON
THE 12Z KSHV RAOB...BUT THE LACK OF A FOCUSING MECHANISM FOR THIS
PRECLUDES MENTION IN THE FORECAST ATTM.
THE LACK OF CONVECTION/CLOUD COVER THIS MORNING HAS ALLOWED TEMPS
TO QUICKLY REACH THE UPPER 80S/LOWER 90S AS OF 16Z...THUS HAVE
BUMPED UP MAX TEMPS AREAWIDE A FEW DEGREES. HEAT INDICES MAY
BRIEFLY APPROACH HEAT ADVISORY CRITERIA THIS AFTERNOON OVER
PORTIONS OF E TX/N LA WHERE MOISTURE POOLING IS EVIDENT NEAR/S OF
THE SFC TROUGH...BUT GIVEN THE EXPECTATION OF SCT CONVECTION
FIRING THIS AFTERNOON...WILL FOREGO THE ISSUANCE OF A HEAT
ADVISORY ATTM.
THE CONVECTION SHOULD QUICKLY DIMINISH THIS EVENING AS THE BNDRY
LYR STABILIZES...AND DRIER AIR ALOFT BEGIN TO MIX S INTO THE
REGION WITH THE PASSAGE OF THE LONGWAVE TROUGH...WHICH SHOULD
EVENTUALLY REINFORCE THE SFC TROUGH S THROUGH THE AREA.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 90 69 91 / 40 20 0 10 10
MLU 93 73 90 68 89 / 50 20 10 10 10
DEQ 92 67 87 61 88 / 10 10 0 10 10
TXK 94 72 88 64 88 / 20 10 0 10 10
ELD 91 71 89 64 88 / 20 10 0 10 10
TYR 94 73 91 67 91 / 40 10 0 10 10
GGG 94 73 90 65 90 / 40 20 0 10 10
LFK 97 76 93 69 94 / 50 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1139 AM CDT MON AUG 11 2014
.DISCUSSION...
THE EARLY MORNING CONVECTION OVER SW AR HAS QUICKLY EXITED THE
REGION TO THE E INTO SE AR/EXTREME NE LA...WITH AN ATTENDANT
OUTFLOW BNDRY SHIFTING SE ACROSS SE UNION AND LINCOLN
PARISHES...WITH A 2ND BNDRY FARTHER TO THE SE ACROSS NE WINN/SRN
OUACHITA PARISHES. ISOLATED -SHRA HAVE DIMINISHED IN THE LAST HOUR
WITH VERY QUIET CONDITIONS IN PLACE ACROSS THE REMAINDER OF THE
REGION. THE 16Z SFC ANALYSIS INDICATED A WEAK SURFACE TROUGH
SITUATED W TO E ALONG THE I-20 CORRIDOR OF NCNTRL/NE TX/N
LA...ALTHOUGH THE SLIGHTLY DRY AIR LAGS THIS TROUGH A WAYS INTO SE
OK/NW AR. THE SHORT TERM PROGS SUGGEST THAT THIS SFC TROUGH WILL
NOT MOVE MUCH FARTHER S THIS AFTERNOON...UNLESS CONVECTIVELY
REINFORCED...GIVEN THE WEAK PRESSURE RISES TO THE N AND THE
SHALLOW NATURE OF THE FRONT. MEANWHILE...WATER VAPOR IMAGERY
DEPICTS A LONGWAVE TROUGH DIGGING SE THROUGH THE PLAINS THIS
MORNING...WITH THE UPPER TROUGH AXIS EXTENDING FROM NRN OK/SRN
MO...NE TO LAKE MI. SCT CONVECTION TO THE W JUST S OF THE RED
RIVER OF N TX THIS MORNING BEHIND THE SFC TROUGH CONTINUES TO
DIMINISH ATTM...WITH THE 06Z AND 12Z GFS NOT BULLISH AT ALL IN
CONVECTION DEVELOPING ONCE FURTHER DESTABILIZATION IS REALIZED
THIS AFTERNOON WITH ADDED HEATING. MEANWHILE...THE 12Z WRF AND
LATEST HRRR RUNS SUGGEST THAT SCT CONVECTION WILL DEVELOP AFTER 18Z
MAINLY ALONG/S OF THE I-20 CORRIDOR NEAR/S OF THE SFC
TROUGH...WHERE PW/S EXCEEDING 2.10 INCHES AND STRONG HEATING WILL
CONTRIBUTE TO STEEPER LOW LEVEL LAPSE RATES/3000+ J/KG MLCAPE.
HOWEVER...DEEP LAYER SHEAR AND FORCING SHOULD REMAIN WEAK...WITH
THE CONVECTION PRIMARILY OUTFLOW DRIVEN.
GIVEN THIS...HAVE TRIMMED BACK POPS TO CHANCE ACROSS MUCH OF E
TX/N LA...TAPERING TO SLIGHT CHANCE ACROSS EXTREME NE TX/FAR SRN
AR. HAVE DROPPED POPS FARTHER N ACROSS SE OK/NRN SECTIONS OF SW AR
GIVEN THE ABSENCE OF FRONTAL FORCING AND INTRUSION OF DEEP LEVEL DRIER
AIR. STILL CAN/T RULE OUT BRIEF HEAVY RAINFALL IN THE STRONGER
STORMS GIVEN THE HIGH PW/S AND VERY DEEP WARM LAYER INDICATED ON
THE 12Z KSHV RAOB...BUT THE LACK OF A FOCUSING MECHANISM FOR THIS
PRECLUDES MENTION IN THE FORECAST ATTM.
THE LACK OF CONVECTION/CLOUD COVER THIS MORNING HAS ALLOWED TEMPS
TO QUICKLY REACHING THE UPPER 80S/LOWER 90S AS OF 16Z...THUS HAVE
BUMPED UP MAX TEMPS AREAWIDE A FEW DEGREES. HEAT INDICES MAY
BRIEFLY APPROACH HEAT ADVISORY CRITERIA THIS AFTERNOON OVER
PORTIONS OF E TX/N LA WHERE MOISTURE POOLING IS EVIDENT NEAR/S OF
THE SFC TROUGH...BUT GIVEN THE EXPECTATION OF SCT CONVECTION
FIRING THIS AFTERNOON...WILL FOREGO THE ISSUANCE OF A HEAT
ADVISORY ATTM.
THE CONVECTION SHOULD QUICKLY DIMINISH THIS EVENING AS THE BNDRY
LYR STABILIZES...AND DRIER AIR ALOFT BEGIN TO MIX S INTO THE
REGION WITH THE PASSAGE OF THE LONGWAVE TROUGH...WHICH SHOULD
EVENTUALLY REINFORCE THE SFC TROUGH S THROUGH THE AREA.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 90 69 91 / 40 20 0 10 10
MLU 93 73 90 68 89 / 50 20 10 10 10
DEQ 92 67 87 61 88 / 10 10 0 10 10
TXK 94 72 88 64 88 / 20 10 0 10 10
ELD 91 71 89 64 88 / 20 10 0 10 10
TYR 94 73 91 67 91 / 40 10 0 10 10
GGG 94 73 90 65 90 / 40 20 0 10 10
LFK 97 76 93 69 94 / 50 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST.
WITH MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 702 PM EDT MON AUG 11 2014
MVFR CONDITIONS WILL CONTINUE AT IWD THROUGH TONIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP IFR CIGS GOING AT CMX
TONIGHT AND SHOULD LOWER CIGS AT SAW TO IFR/LIFR TONIGHT. KCMX
SHOULD SEE SOME IMPROVEMENT FROM IFR CONDITIONS LATER TONIGHT AS
RAIN MOVES OUT AND SHOULD BE VFR WITH DRIER AIR BY TUE AFTERNOON.
CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL KEEP LOW CIGS
AT KSAW INTO TUESDAY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST.
WITH MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 11 2014
VFR CONDITIONS WITH SOME OCCASIONAL MVFR CIGS ARE POSSIBLE AT IWD
BEHIND THE MAIN AREA OF RAIN. HOWEVER CONFIDENCE IS LOW UNTIL LATER
TONIGHT WHEN MORE SUBSTANTIAL DRYING MOVES IN AND KEEPS CIGS IN THE
VFR RANGE.
RAIN ALONG WITH MOIST NORTHERLY FLOW SPREADING FROM WEST TO EAST
THROUGH WEST/CENTRAL UPPER MICHIGAN WILL KEEP IFR CIGS GOING AT CMX INTO
THIS EVENING AND SHOULD LOWER CIGS AT SAW FROM MVFR LATE THIS
AFTERNOON TO IFR TONIGHT. KCMX SHOULD SEE SOME IMPROVEMENT FROM IFR
CONDITIONS OVERNIGHT TONIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH
CENTRAL U.P. WILL KEEP LOW CIGS AT KSAW INTO TUESDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...JLB
MARINE...MZ
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1253 PM CDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 235 AM CDT MON AUG 11 2014
AT THE SURFACE...HIGH PRESSURE EXTENDED FROM SOUTHEAST
SASKATCHEWAN TO NORTHEAST COLORADO. THERE WAS A STATIONARY FRONT
ACROSS THE SOUTHERN PLAINS WITH AN EXTENSION THROUGH A WEAK
FRONT/TROUGH ON THE EASTERN PLAINS AND FOOTHILLS OF WYOMING AND
COLORADO. ANOTHER BOUNDARY OR FRONT COULD BE SEEN IN THE GOES
INFRA-RED IMAGERY WITH A NARROW BAND OF MIDDLE AND HIGH CLOUDS
ACROSS SOUTHERN SOUTH DAKOTA.
AN UPPER LEVEL DISTURBANCE ACROSS WESTERN MEXICO IS FORECAST TO
LIFT NORTH THROUGH THE SOUTHWESTERN U.S. AND AFFECT WESTERN/NCNTL
NEB WITH SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY.
THE ECM IS THE WET MODEL FORECASTING AROUND 1 INCH OF RAIN ACROSS
MOST OF THE FORECAST AREA.
&&
.UPDATE...
ISSUED AT 1142 AM CDT MON AUG 11 2014
ISOLATED SHOWERS AND THUNDERSTORMS WERE ADDED INTO THE FORECAST FOR
THE WESTERN PART OF THE FORECAST AREA...GENERALLY WEST OF A LINE
FROM MERRIMAN THROUGH NORTH PLATTE. CLOUDS HAD DEVELOPED ALONG A
BOUNDARY ALOFT THIS MORNING...WHERE THE RAP SHOWS INCREASED
CONVERGENCE IN THE 850MB TO 700MB LAYER IN THE GENERAL AREA
THROUGHOUT THE AFTERNOON. MOISTURE IS FAIRLY SHALLOW AND LIMITED
SO DON/T EXPECT MORE THAN ISOLATED TO SCATTERED ACTIVITY. THE LIFT
AND MOISTURE DIMINISH BY 00Z THIS EVENING WITH THE NEW FORECAST
TRENDING TO LIMIT PRECIPITATION CHANCES BY THIS EVENING AS WELL.
UPDATE ISSUED AT 915 PM CDT MON AUG 11 2014
FORECAST WAS UPDATED FOR THIS MORNING FOR THE DISSIPATION OF FOG
ACROSS MOST AREAS. VISIBLE SATELLITE SHOWED A PATCH OF CLOUDS FROM
EAST CENTRAL LINCOLN COUNTY UP THROUGH NORTHEAST CUSTER
COUNTY...BUT BELIEVE THIS WAS LOW STRATUS RATHER THAN FOG DUE TO
OBSERVATION AT KBBW OF 300FT CEILINGS. HOWEVER AREA WEBCAMS DO
SHOW SOME LIGHT FOG /VISIBILITY AROUND 5SM OVER SOUTHWEST CUSTER
COUNTY. THIS IS LIKELY BEING OBSERVED UNDER MUCH OF THE AREA.
OTHER LOCATIONS WERE ALSO SEEING SOME HAZY CONDITIONS THIS
MORNING. ALL SHOULD MIX OUT AND DISSIPATE BY LATER THIS MORNING.
UPDATE ISSUED AT 630 AM CDT MON AUG 11 2014
SATELLITE AND METAR OBSERVATIONS INDICATE PATCHY FOG HAS FORMED
OVER CENTRAL AND PART OF SOUTHWEST NEBRASKA. WITH SIMILAR MOISTURE
AND WIND CONDITIONS AROUND THE AREA...THERE IS NO REASON TO THINK
THAT IT WILL NOT ALSO AFFECT NORTH CENTRAL AND SOUTHWEST NEBRASKA.
THEREFORE...WE HAVE UPDATED THE FORECAST TO REFLECT PATCHY FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM CDT MON AUG 11 2014
WITH HIGH PRESSURE THE DOMINANT FEATURE AT THE SURFACE AND ALOFT...
LOW LEVEL FLOW WILL BECOME EAST TO SOUTHEAST BY THIS EVENING AND THE
LEE SIDE TROUGH WILL BEGIN REDEVELOPING. HOWEVER...THE FETCH DOES
NOT REACH A SIGNIFICANT MOISTURE SOURCE YET AND PRECIPITATION IS
UNLIKELY TODAY OR TONIGHT IN CENTRAL NEBRASKA...THE SANDHILLS OR THE
EASTERN PANHANDLE. TEMPERATURES ARE TODAY AND TONIGHT ARE EXPECTED
TO BE BELOW AVERAGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 AM CDT MON AUG 11 2014
CANADIAN HIGH PRESSURE WILL MOVE OFF EAST TUESDAY SETTING UP
MOISTURE RETURN. BY WEDNESDAY DEW POINTS INCREASE INTO THE LOWER
60S. THERE APPEARS TO BE SUFFICIENT INSTABILITY FOR TSTM DEVELOPMENT
BY WEDNESDAY EVENING. ALL MODELS DEVELOP CONVECTION NORTH WEDNESDAY
NIGHT AND IT WOULD APPEAR TO BE DRIVEN BY WARM AIR ADVECTION
ASSOCIATED WITH AN H700MB LOW MOVING THROUGH THE ROCKIES.
THE GENESIS OF THIS H700MB LOW IS A SUBTROPICAL DISTURBANCE
CURRENTLY ACROSS WRN MEXICO. THE DISTURBANCE LIFTS NORTH THROUGH
THE SWRN U.S. ARRIVING IN WRN/NCNTL NEB THURSDAY/FRIDAY. THIS
WOULD LIKELY BE THE BEST CHANCE FOR RAIN DURING THE NEXT 7 DAYS
WITH MEAN RH 850-300MB INCREASING TO 70 TO 80 PERCENT BOTH DAYS. A
CLOSED H700MB LOW SHOULD TRACK THROUGH THE FCST AREA THURSDAY AND
SLOW UP LASTING THROUGH FRIDAY. THE ECM IS EVEN SLOWER WITH RAIN
CHANCES LASTING THROUGH SATURDAY.
THEREAFTER...AN UPPER LOW...CURRENTLY ACROSS THE GULF
ALASKA...SHOULD DROP THROUGH THE NRN ROCKIES FRIDAY AND MOVE THROUGH
THE NRN PLAINS SATURDAY. THIS WOULD DRAW PACIFIC AIR THROUGH WYOMING
AND THE NEB PANHANDLE SHUNTING MOISTURE EAST OF THE FCST AREA AS
SHOWN BY THE MODELS. THIS IS NOT ALWAYS THE CASE THOUGH. WEAK
PACIFIC COLD FRONTS CAN STALL LEAVING A BROAD AREA OF SFC LOW
PRESSURE WHICH WOULD POOL MOISTURE INCREASING RAIN CHANCES. AS SUCH
THE GFS AND ECM SHOW A DRY LINE ALONG HIGHWAY 61 WITH DEW POINTS
INCREASING TO THE MID 60S SUNDAY TO THE EAST.
THE POP FORECAST STARTS WITH ISOLATED CHANCES LATE WEDNESDAY
AFTERNOON IN THE PANHANDLE WHICH INCREASE TO NEAR 40 THURSDAY NIGHT
AND ISOLATED FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 152 PM CDT MON AUG 11 2014
HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS HAS LED TO
GENERALLY QUIET WEATHER ACROSS NEBRASKA. CLOUDS HAD DEVELOPED
THROUGH THE DAY ON THE BACK SIDE OF THE SURFACE HIGH WHERE MORE
MOISTURE WAS IN PLACE. LOOKING FOR SOME ISOLATED TO SCATTERED
CONVECTION THIS AFTERNOON...BUT ACTIVITY SHOULD BE WEST OF A LINE
FROM AROUND MERRIMAN TO NORTH PLATTE. ALTHOUGH THERE IS A CHANCE
FOR SHOWERS OR STORMS AT KLBF...WITH ACTIVITY EXPECTED TO BE
ISOLATED...DIDN/T HAVE THE CONFIDENCE TO ADD ANY CONVECTIVE
CIRCUMSTANCES IN THE FORECAST AND WILL JUST MONITOR THROUGH THE
AFTERNOON. OTHERWISE...WITH HIGH PRESSURE IN CONTROL THE WEATHER
SHOULD BE QUIET WITH GENERALLY LIGHT WINDS. THERE IS A CONCERN IF
FOG WILL DEVELOP TONIGHT ON THE BACKSIDE OF THE SURFACE HIGH. THE
LOCAL AREA WILL BE IN THE FAVORED REGION...BUT DON/T HAVE THE
CONFIDENCE THAT THERE WILL BE ENOUGH BOUNDARY LAYER MOISTURE FOR
DEVELOPMENT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SYNOPSIS...CDC
SHORT TERM...SPRINGER
LONG TERM...CDC
AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1143 AM CDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 235 AM CDT MON AUG 11 2014
AT THE SURFACE...HIGH PRESSURE EXTENDED FROM SOUTHEAST
SASKATCHEWAN TO NORTHEAST COLORADO. THERE WAS A STATIONARY FRONT
ACROSS THE SOUTHERN PLAINS WITH AN EXTENSION THROUGH A WEAK
FRONT/TROUGH ON THE EASTERN PLAINS AND FOOTHILLS OF WYOMING AND
COLORADO. ANOTHER BOUNDARY OR FRONT COULD BE SEEN IN THE GOES
INFRA-RED IMAGERY WITH A NARROW BAND OF MIDDLE AND HIGH CLOUDS
ACROSS SOUTHERN SOUTH DAKOTA.
AN UPPER LEVEL DISTURBANCE ACROSS WESTERN MEXICO IS FORECAST TO
LIFT NORTH THROUGH THE SOUTHWESTERN U.S. AND AFFECT WESTERN/NCNTL
NEB WITH SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY.
THE ECM IS THE WET MODEL FORECASTING AROUND 1 INCH OF RAIN ACROSS
MOST OF THE FORECAST AREA.
&&
.UPDATE...
ISSUED AT 1142 AM CDT MON AUG 11 2014
ISOLATED SHOWERS AND THUNDERSTORMS WERE ADDED INTO THE FORECAST FOR
THE WESTERN PART OF THE FORECAST AREA...GENERALLY WEST OF A LINE
FROM MERRIMAN THROUGH NORTH PLATTE. CLOUDS HAD DEVELOPED ALONG A
BOUNDARY ALOFT THIS MORNING...WHERE THE RAP SHOWS INCREASED
CONVERGENCE IN THE 850MB TO 700MB LAYER IN THE GENERAL AREA
THROUGHOUT THE AFTERNOON. MOISTURE IS FAIRLY SHALLOW AND LIMITED
SO DON/T EXPECT MORE THAN ISOLATED TO SCATTERED ACTIVITY. THE LIFT
AND MOISTURE DIMINISH BY 00Z THIS EVENING WITH THE NEW FORECAST
TRENDING TO LIMIT PRECIPITATION CHANCES BY THIS EVENING AS WELL.
UPDATE ISSUED AT 915 PM CDT MON AUG 11 2014
FORECAST WAS UPDATED FOR THIS MORNING FOR THE DISSIPATION OF FOG
ACROSS MOST AREAS. VISIBLE SATELLITE SHOWED A PATCH OF CLOUDS FROM
EAST CENTRAL LINCOLN COUNTY UP THROUGH NORTHEAST CUSTER
COUNTY...BUT BELIEVE THIS WAS LOW STRATUS RATHER THAN FOG DUE TO
OBSERVATION AT KBBW OF 300FT CEILINGS. HOWEVER AREA WEBCAMS DO
SHOW SOME LIGHT FOG /VISIBILITY AROUND 5SM OVER SOUTHWEST CUSTER
COUNTY. THIS IS LIKELY BEING OBSERVED UNDER MUCH OF THE AREA.
OTHER LOCATIONS WERE ALSO SEEING SOME HAZY CONDITIONS THIS
MORNING. ALL SHOULD MIX OUT AND DISSIPATE BY LATER THIS MORNING.
UPDATE ISSUED AT 630 AM CDT MON AUG 11 2014
SATELLITE AND METAR OBSERVATIONS INDICATE PATCHY FOG HAS FORMED
OVER CENTRAL AND PART OF SOUTHWEST NEBRASKA. WITH SIMILAR MOISTURE
AND WIND CONDITIONS AROUND THE AREA...THERE IS NO REASON TO THINK
THAT IT WILL NOT ALSO AFFECT NORTH CENTRAL AND SOUTHWEST NEBRASKA.
THEREFORE...WE HAVE UPDATED THE FORECAST TO REFLECT PATCHY FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM CDT MON AUG 11 2014
WITH HIGH PRESSURE THE DOMINANT FEATURE AT THE SURFACE AND ALOFT...
LOW LEVEL FLOW WILL BECOME EAST TO SOUTHEAST BY THIS EVENING AND THE
LEE SIDE TROUGH WILL BEGIN REDEVELOPING. HOWEVER...THE FETCH DOES
NOT REACH A SIGNIFICANT MOISTURE SOURCE YET AND PRECIPITATION IS
UNLIKELY TODAY OR TONIGHT IN CENTRAL NEBRASKA...THE SANDHILLS OR THE
EASTERN PANHANDLE. TEMPERATURES ARE TODAY AND TONIGHT ARE EXPECTED
TO BE BELOW AVERAGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 AM CDT MON AUG 11 2014
CANADIAN HIGH PRESSURE WILL MOVE OFF EAST TUESDAY SETTING UP
MOISTURE RETURN. BY WEDNESDAY DEW POINTS INCREASE INTO THE LOWER
60S. THERE APPEARS TO BE SUFFICIENT INSTABILITY FOR TSTM DEVELOPMENT
BY WEDNESDAY EVENING. ALL MODELS DEVELOP CONVECTION NORTH WEDNESDAY
NIGHT AND IT WOULD APPEAR TO BE DRIVEN BY WARM AIR ADVECTION
ASSOCIATED WITH AN H700MB LOW MOVING THROUGH THE ROCKIES.
THE GENESIS OF THIS H700MB LOW IS A SUBTROPICAL DISTURBANCE
CURRENTLY ACROSS WRN MEXICO. THE DISTURBANCE LIFTS NORTH THROUGH
THE SWRN U.S. ARRIVING IN WRN/NCNTL NEB THURSDAY/FRIDAY. THIS
WOULD LIKELY BE THE BEST CHANCE FOR RAIN DURING THE NEXT 7 DAYS
WITH MEAN RH 850-300MB INCREASING TO 70 TO 80 PERCENT BOTH DAYS. A
CLOSED H700MB LOW SHOULD TRACK THROUGH THE FCST AREA THURSDAY AND
SLOW UP LASTING THROUGH FRIDAY. THE ECM IS EVEN SLOWER WITH RAIN
CHANCES LASTING THROUGH SATURDAY.
THEREAFTER...AN UPPER LOW...CURRENTLY ACROSS THE GULF
ALASKA...SHOULD DROP THROUGH THE NRN ROCKIES FRIDAY AND MOVE THROUGH
THE NRN PLAINS SATURDAY. THIS WOULD DRAW PACIFIC AIR THROUGH WYOMING
AND THE NEB PANHANDLE SHUNTING MOISTURE EAST OF THE FCST AREA AS
SHOWN BY THE MODELS. THIS IS NOT ALWAYS THE CASE THOUGH. WEAK
PACIFIC COLD FRONTS CAN STALL LEAVING A BROAD AREA OF SFC LOW
PRESSURE WHICH WOULD POOL MOISTURE INCREASING RAIN CHANCES. AS SUCH
THE GFS AND ECM SHOW A DRY LINE ALONG HIGHWAY 61 WITH DEW POINTS
INCREASING TO THE MID 60S SUNDAY TO THE EAST.
THE POP FORECAST STARTS WITH ISOLATED CHANCES LATE WEDNESDAY
AFTERNOON IN THE PANHANDLE WHICH INCREASE TO NEAR 40 THURSDAY NIGHT
AND ISOLATED FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON AUG 11 2014
LIMITED COVERAGE OF BR/FG WILL CONTINUE AFFECTING CENTRAL AND
WESTERN NEBRASKA. SINCE IT HAS ALREADY SHOWN UP AT LBF...WE WILL
INCLUDE BCFG IN THE TERMINAL FORECAST WITH VISIBILITY AT OR ABOVE
3SM AND A TEMPO TO 1SM. WITH NO CLOUDINESS ABOVE THE SURFACE...IT
SHOULD CLEAR OUT QUICKLY THIS MORNING. THEN...FOR THE REST OF THE
DAY... CEILING AND VISIBILITY WILL BE UNLIMITED. FOR
TONIGHT...THERE IS A POSSIBILITY FOR SIMILAR CONDITIONS AND FOG IS
POSSIBLE. AGAIN... THOUGH...COVERAGE WILL BE LIMITED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SYNOPSIS...CDC
SHORT TERM...SPRINGER
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
325 PM PDT MON AUG 11 2014
.SYNOPSIS...MONSOON MOISTURE PUSHING IN FROM THE SOUTHEAST WILL
RESULT IN INCREASED THUNDERSTORM COVERAGE THROUGH WEDNESDAY. DRIER
AIR WILL ONCE AGAIN GRADUALLY MOVE IN FROM THE SOUTHWEST STARTING
THURSDAY WITH THUNDERSTORM CHANCES CONFINED TO MOHAVE COUNTY BY
FRIDAY.
&&
.SHORT TERM...THROUGH TUESDAY NIGHT...
TAIL END OF LINE OF STORMS WHICH WAS OVER INYO/ESMERALDA COUNTY THIS
MORNING DID SHIFT EASTWARD AND DID AFFECT SRN NYE/CLARK COUNTIES
THIS AFTERNOON. THOSE STORMS NOW MOVING INTO LINCOLN COUNTY.
ACTIVITY IS GETTING GOING OVER MOHAVE COUNTY WITH
MORE STORMS SET TO ENTER MOHAVE COUNTY FROM COCONINO/YAVAPAI
COUNTIES. HRRR SUGGEST THE NORTHERN TWO-THIRDS OF MOHAVE COUNTY WILL
REMAIN THE MOST ACTIVE FOR THE NEXT 3-4 HOURS THEN SHIFTING
NORTHWARD ACROSS NORTHEAST CLARK AND LINCOLN COUNTIES THIS EVENING.
GUSTS OF 40-50 MPH...SMALL HAIL AND BRIEF HEAVY RAIN POSSIBLE WITH
STORMS.
FOR TUESDAY...MODELS MORE OR LESS IN GOOD AGREEMENT SHOWING AN
INVERTED TROUGH MOVING EAST ACROSS SOUTHERN ARIZONA TONIGHT AND INTO
SOUTHWEST ARIZONA LATE TUESDAY AFTERNOON. INVERTED TROUGH THEN
ENCOUNTERS A MORE WESTERLY FLOW AND LIFT NORTH ACROSS WESTERN
ARIZONA TUESDAY NIGHT/WEDNESDAY. DUE TO ADDITIONAL DYNAMICS DECIDED
TO ISSUE A FLASH FLOOD WATCH FOR THE NORTHWEST DESERT AND PLATEAU OF
MOHAVE COUNTY FROM 11 AM MST - 10 PM MST TUESDAY. TOMORROW WE WILL
BE LOOKING AT THE NEED OF EXTENDING THE WATCH INTO WEDNESDAY IF
MODELS STAY CONSISTENT.
.LONG TERM...WEDNESDAY THROUGH SUNDAY...THE SYNOPTIC PATTERN
FEATURES A LOW PRESSURE TROUGH OVER THE PACIFIC NW WEDNESDAY THAT IS
FORECAST TO MOVE INTO THE NORTHERN GREAT BASIN THURSDAY AND FRIDAY.
THE UPPER LEVEL FLOW BECOMES SOLIDLY WEST TO SOUTHWEST AS THE WEEK
WEARS ON. THE AFFECT OF THIS LARGE SCALE FEATURE ON SENSIBLE WEATHER
WITHIN THE FORECAST AREA IS TO BRING A DECREASING TREND IN
THUNDERSTORM COVERAGE.
WEDNESDAY HAS THE BEST POTENTIAL FOR SCATTERED THUNDERSTORMS ACROSS
A WIDER AREA INCLUDING LINCOLN, CLARK, MOHAVE AND EASTERN SAN BERN
COUNTIES. BEYOND WEDNESDAY, RAPID DRYING TAKES PLACE IF THE GFS
VERIFIES BUT COULD BE SOMEWHAT SLOWER PER THE ECMWF. MAINTAINED A
MENTION OF STORMS IN MOHAVE COUNTY BOTH THURSDAY AND FRIDAY BEFORE
DRYING THEM OUT COMPLETELY OVER THE WEEKEND. TEMPERATURES WILL
GENERALLY BE BELOW NORMAL MID TO LATE IN THE WEEK THEN BECOME
SEASONAL OVER THE WEEKEND.
&&
.AVIATION...FOR MCCARRAN...OUTFLOW WINDS FROM SURROUNDING STORMS
WILL CONTINUE TO AFFECT LAS VEGAS VALLEY TERMINALS INTO THE EVENING
HOURS. LOOKS LIKE WINDS WILL FAVOR A NORTHERLY DIRECTION FOR SEVERAL
HOURS BEFORE TRANSITION BACK TO OUR TYPICAL SOUTH/SOUTHWEST
DIRECTION WITH SPEEDS OF 7-11 KTS. CONVECTION SHOULD IMPACT MAINLY
THE BEATTY...MORMON MESA AND PEACH SPRINGS CORRIDORS THIS EVENING.
THERE WILL BE ANOTHER CHANCE OF SHOWERS OR TSTORM WITHIN THE
VICINITY OF THE TERMINAL TUESDAY...WHICH COULD BRING GUSTY AND
ERRATIC WINDS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED-BROKEN CLOUDS ALONG WITH ISOLATED TO
SCATTERED THUNDERSTORMS ACROSS ALL OF SOUTHEAST
CALIFORNIA...SOUTHERN NEVADA AND NORTHWEST ARIZONA THIS EVENING AND
AGAIN TUESDAY. WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS
THROUGH TUESDAY...EXCEPT NEAR THUNDERSTORMS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT INSTANCES OF
FLASH FLOODING...STRONG GUSTY WINDS...HAIL...AND BLOWING DUST TODAY
THROUGH TUESDAY.
&&
$$
SHORT TERM/AVIATION...PIERCE
LONG TERM...SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
330 PM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR ADDITIONAL RAINFALL OVER ALREADY WET
GROUND. A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT
WEDNESDAY...BRINGING DRIER CONDITIONS AND COOLER NIGHT-TIME
TEMPERATURES INTO LATE WEEK. SEASONABLE WEATHER IS EXPECTED THIS
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 330 PM MONDAY...CANCELED THE FLOOD WATCH WITH THE LAST
FORECAST UPDATE. WIDESPREAD SHOWERS HAVE CERTAINLY POPPED UP...BUT
THEY HAVE REMAINED VERY SHALLOW/COMPLETELY CONFINED TO AREAS BELOW
THE FREEZING LEVEL. STRONG MID LEVEL NEGATIVE VORTICITY
ADVECTION/DOWNWARD VERTICAL MOTION LIKELY TO BLAME...AND THIS WILL
NOT CHANGE UNTIL THE VORT MIN CROSSES AT 00Z. THE SHALLOWNESS OF
THE STORMS HAS LEAD TO THEM BEING STEERED BY THE NEARLY
UNIDIRECTIONAL ONSHORE FLOW AND INDIVIDUAL ELEMENTS ARE SHOWING
MOTIONS OF 8-12KT. WITH SHALLOWER AND THUS LIGHTER SHOWER ACTIVITY
AND A HIGHER STORM MOTION THAN PREV EXPECTED THE THREAT FOR
WIDESPREAD FLOODING LIKELY WON`T MATERIALIZE. ITS STILL TOUGH TO
RULE OUT ONE PROBLEM SPOT OR TWO BUT THEY WOULD BE BETTER HANDLED
WITH SHORT-FUSED ADVISORIES OR WARNINGS. MODELS ARE STRUGGLING
WITH THE MESOSCALE DETAIL BUT THE RUC SEEMS TO BE SOMEWHAT WELL
INITIALIZED. IT FAVORS PRECIP JUST NORTH OF THE STATE LINE FOR THE
NEXT FEW HOURS...DRIFTING NORTH AND WEST. SATELLITE TRENDS SHOW A
POSSIBLE MINIMUM IN ACTIVITY ALONG THE GRAND STRAND WHERE CU
FIELDS ARE LEAST DEVELOPED BUT IT`LL BE TOUGH TO HAVE A POP OF
LESS THAN 20 FOR MOST OF THE AREA IN THE VERY NEAR TERM SINCE
DAYTIME HEATING IS THE SOLE FACTOR DRIVING DEVELOPMENT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ONE MORE DAY OF UNSETTLED WEATHER TUE SHOULD
GIVE WAY TO MID-LEVEL DRYING AND MORE SEASONABLE TEMPS ON WED. THE
PERIOD BEGINS WITH AN UPPER TROUGH OVER THE GREAT LAKES WHICH WILL
DIG AS IT MOVES EASTWARD THROUGH WED. MEANWHILE THE STALLED FRONT
THAT HAS PLAGUED OUR REGION FOR DAYS...AND ITS ASSOCIATED SFC
LOW...WILL FINALLY LIFT NORTHWARD AS A WARM FRONT DURING THE DAY
TUE. PWATS REMAIN AROUND 2.0 INCHES ON TUE...AND ENOUGH
INSTABILITY SHOULD EXIST FOR AT LEAST SCT CONVECTION DURING THE
DAY. GIVEN OUR LOCATION UNDER THE UPPER DIVERGENT REGION OF THE
TROUGH...ANY WEAK IMPULSES ALOFT WOULD FURTHER ENHANCE OUR PRECIP
CHANCES FOR TUE. POPS WILL RAPIDLY DIMINISH AS THE DAY PROGRESSES
ON WED AS A COLD FRONT MAKES IT WAY INTO OUR CWA. ONCE THE UPPER
TROUGH AXIS CLEARS OUR AREA BY MIDDAY...DRY WESTERLY FLOW ALOFT
WILL CAUSE PWATS TO PLUMMET AS LOW AS 1.0 INCH BY 00Z THU. THIS
WILL BRING US SOME WELCOMED RELIEF FROM THE PERSISTENT CLOUD COVER
AND RAIN WE HAVE DEALT WITH LATELY.
THE WARMER AIR BEHIND THE WARM FRONT WILL LIKELY BE OFFSET BY CLOUDS
AND PRECIP TOMORROW. THEREFORE...HAVE SIDED WITH THE COOLER NAM
GUIDANCE...WHICH YIELDS HIGHS IN THE MID TO UPPER 80S ON TUE.
OVERNIGHT LOWS ON TUE WILL RANGE FROM THE LOWER 70S INLAND TO MID
70S AT THE COAST. WED WILL FEATURE A RETURN TO MORE SEASONABLE HIGHS
AS SUNSHINE FINALLY RETURNS TO THE EASTERN CAROLINAS. DRY WESTERLY
FLOW SHOULD ALLOW HIGHS TO CLIMB TO AROUND 90 INLAND AND UPPER 80S
ALONG THE COAST. COOLER AIR WILL FILTER INTO OUR CWA BEHIND THE COLD
FRONT OVERNIGHT WED...WITH LOWS FALLING INTO THE MID TO UPPER 60S
EVERYWHERE AWAY FROM THE BEACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 330 PM MONDAY...PERIOD BEGINS WITH COLD FRONT STALLED OFF THE
COAST. ALOFT A 5H CUTOFF SITS OVER SOUTHEAST CANADA WITH THE
ASSOCIATED MID LEVEL TROUGH EXTENDING SOUTH OVER THE EASTERN CONUS.
THIS SETUP SHOULD PRODUCE A PERIOD OF DRY WEATHER FOR THE CAROLINAS
WITH DEEP WESTERLY FLOW ENSURING MID LEVELS REMAIN DRY INTO THE
WEEKEND. THU WILL BE THE DRIEST DAY AND IS LIKELY TO BE A DAY
WITHOUT PRECIP. PRECIPITABLE WATER VALUES ARE DOWN AROUND AN INCH
FROM A COMBINATION OF DOWNSLOPE FLOW AND MID LEVEL SUBSIDENCE.
LOW LEVEL RETURN FLOW SETS UP FRI AS SURFACE HIGH MOVES FROM THE
WESTERN GREAT LAKES THU TO THE OH VALLEY FRI. MID LEVEL WESTERLY
FLOW CONTINUES BUT THE INCREASE IN LOW LEVEL MOISTURE DUE TO THE
RETURN FLOW WILL BRING ABOUT A SLIGHT INCREASE IN PRECIP CHANCES.
GIVEN THE AMOUNT OF DRY AIR IN THE MID LEVELS AND THE MARGINAL
THERMODYNAMIC PROFILES IN FORECAST SOUNDINGS DO NOT THINK MORE THAN
A SLIGHT CHC OR SILENT POP IS WARRANTED FRI.
CUTOFF LOW AND MID LEVEL TROUGH START TO LIFT NORTHEAST SAT WHILE AT
THE SURFACE LOW LEVEL RETURN FLOW INCREASES. IN THE WAKE OF THE 5H
TROUGH MID LEVEL PATTERN FLATTENS OUT WITH WEST TO SOUTHWEST FLOW
ALOFT. INCREASED MID LEVEL MOISTURE...ESPECIALLY SUN AND MON...AND A
LITTLE PVA AHEAD OF WEAK SHORTWAVES SHOULD LEAD TO AN INCREASE IN
PRECIP COVERAGE FOR THE END OF THE PERIOD. WILL HOLD ONTO SILENT POP
SAT GIVEN WEAK FORCING AND MARGINAL VERTICAL PROFILES BUT INCREASE
TO CHC POP FOR SUN AND MON.
TEMPERATURES THROUGH THE PERIOD WILL BE NEAR CLIMO WITH HIGHS IN THE
UPPER 80S TO AROUND 90 AND LOWS IN THE LOWER 70S. GUIDANCE CONTINUES
TO KEEP THE FRONT STALLED OFF THE COAST THROUGH THE PERIOD...BUT
WITH 12Z RUNS THE FRONT IS A LITTLE FARTHER SOUTH AND THE FRONTAL
WAVES ARE LESS DEFINED SO FORECAST CONFIDENCE IS INCREASING.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...SHOWERS ARE CONTINUING TO DEVELOP THIS AFTERNOON AND ARE
INCREASING IN COVERAGE. THERE HAS BEEN LITTLE IF ANY LIGHTNING AND
ANY THUNDERSTORMS THIS AFTERNOON ARE EXPECTED TO REMAIN ISOLATED.
MOST SHOWERS THE REMAINDER OF THE DAYLIGHT HOURS SHOULD BE LIGHT.
TERMINALS WILL BE PREDOMINATELY VFR...BUT WILL INCLUDE TEMPO GROUPS
FOR MVFR CIGS/VSBYS INLAND TAFS DUE TO THE SHOWER ACTIVITY. IFR
COULD OCCUR IF CELLS WITH THE HEAVIER RAINFALL MOVE DIRECTLY OVER
A TERMINAL. BUT DUE TO THE ISOLATED COVERAGE OF HEAVY SHOWERS FEEL
THE CHANCE OF IFR WILL BE LOW.
MODELS ALL AGREE THERE WILL BE A DECREASE IN SHOWER ACTIVITY THIS
EVENING AND OVERNIGHT. IFR CONDITIONS IN FOG WILL DEVELOP AT
KFLO/KLBT AFTER MIDNIGHT...WITH TEMPO LIFR POSSIBLE 09-12Z. THE
COASTAL TERMINALS SHOULD REMAIN MVFR OR GREATER. MVFR/VFR WILL
DEVELOP BY MID-MORNING TUESDAY.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUES. IMPROVING CONDITIONS WED AS A FRONT
MOVES OFFSHORE. VFR THURS THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM MONDAY...ONSHORE FLOW TO CONTINUE THROUGH THE PERIOD.
FRONTAL BOUNDARY STALLED WELL SOUTH OF THE AREA WILL HAVE A FLAT
WAVE TRAVERSE THE REGION LATE IN THE PERIOD. THIS WILL LEAD TO A
GRADUAL DECREASE IN WIND SPEED AND ALSO SOME SLIGHT BACKING IN THE
WIND DIRECTION. HEADING IN TO THE OVERNIGHT THE WINDS ARE A LITTLE
STRONGER OVER NRN WATERS COMPARED TO SOUTHERN ZONES AND SO HAVE
ABOUT AN OVER ALL FOOT HIGHER WAVES. WITH THE SLACKING OF THE
WINDS EXPECTED NRN WATERS WILL SEE MORE OF A DECREASE IN WAVES AND
ALL ZONES SHOULD SETTLE IN TO THE 2 TO 3 FT RANGE...STILL HIGHEST
NORTH.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...THE STALLED FRONT TO OUR SOUTH WILL FINALLY
LIFT BACK NORTH AS A WARM FRONT ON TUE...AS WEST WINDS BECOME
SOUTHWEST AROUND 10 KT DURING THE DAY. SEAS WILL BE IN THE 2-3 FT
RANGE...BUILDING TO 3-4 FT OVERNIGHT AS THE GRADIENT TIGHTENS AND
SOUTHWEST WINDS STRENGTHEN TO AROUND 15 KT. 3 FT SEAS WILL PREVAIL
ON WEDNESDAY WITHIN W-SW FLOW AHEAD OF AN APPROACHING COLD FRONT.
THIS FRONT WILL REACH THE COASTAL WATERS OVERNIGHT WED. WINDS WILL
VEER TO THE NORTHWEST AND THEN NORTH BEHIND THE FRONT EARLY THU...
REMAINING AOB 10 KTS. THESE OFFSHORE WINDS WILL KNOCK DOWN SEAS TO
2-3 FT BY THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 330 PM MONDAY...NORTHEAST FLOW AROUND 10 KT AT THE START OF
THE PERIOD WILL WEAKEN THU AS GRADIENT RELAXES. WINDS WILL VEER TO
EASTERLY BY THU AFTERNOON AND SOUTHEAST THU NIGHT. WEAK GRADIENT
IN PLACE THROUGH THE END OF THE PERIOD WILL KEEP SOUTHERLY WINDS
10 KT OR LESS FRI AND SAT. ONSHORE FLOW WILL DEVELOP NEAR SHORE
EACH DAY WITH THE SEA BREEZE WITH WINDS A COUPLE KT STRONGER. SEAS
2 TO 3 FT AT THE START OF THE PERIOD DROP TO AROUND 2 FT THU
AFTERNOON AND REMAIN AROUND 2 FT THROUGH SAT.
&&
.TIDES/COASTAL FLOODING...
AS OF 330 PM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT- TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...BJR
LONG TERM...III
AVIATION...MBB/MRR
MARINE...III/MBB/BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EDT MON AUG 11 2014
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY MOVE NORTHEAST AWAY FROM
THE REGION...AS A WARM FRONT SLOWLY MOVES NORTH OVER THE CAROLINAS
THROUGH THE DAY TUESDAY. A COLD FRONT FOLLOWS QUICKLY FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE MOVES OVER
MOST OF THE REGION FROM THE WEST WEDNESDAY AND WEDNESDAY NIGHT WITH
DRIER AIR FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...
CERTAINLY A FAIR AMOUNT OF LOW-LEVEL DRYING TOOK PLACE IN CENTRAL
NORTH CAROLINA TODAY...ENOUGH TO RESULT IN AMPLE WARMING AND MORE OF
A CONVECTIVE APPEARANCE TO PRECIPITATION IN MOST PLACES AS OPPOSED
TO STRATIFORM...WITH THE POSSIBLE EXCEPTION OF THE IMMEDIATE TRIAD
TOWARD KINT. THERE WAS LIMITED LIGHTNING WITH THE CONVECTION...
OUTSIDE OF A STRIKE OR TWO SOUTH OF KLBT. SCATTERED-TO-NUMEROUS
SHOWERS WILL CONTINUE FOR THE LATE AFTERNOON INTO THE EVENING...
WITH ENOUGH INSTABILITY MAINLY SOUTH OF U.S. 64...WHERE THE SPC
MESOANALYSIS NOTES AROUND 500J/KG...TO PROVIDE FOR A CHANCE OF A
THUNDERSTORM. DURING THE EVENING HOURS...INCREASING STABILITY TAKING
PLACE DIURNALLY ALONG WITH THE BETTER MOISTURE AXIS BEING LOCATED
CLOSER TO THE NORTHWEST PIEDMONT WILL RESULT IN HIGHER CHANCES OF
SHOWERS IN THE WESTERN PIEDMONT AND ESPECIALLY TOWARD THE IMMEDIATE
TRIAD BY THE OVERNIGHT HOURS. EAST OF U.S. 1 LATE TONIGHT...WHILE
RETAINING A SMALL CHANCE FOR PRECIPITATION...MUCH OF THE GUIDANCE
INCLUDING THE HRRR WRF SUGGESTS LITTLE TAKING PLACE. CLOUDS SHOULD
LOWER AND THE OVERALL AIR MASS MOISTEN OVERNIGHT AS THE SURFACE HIGH
STARTS TO RETREAT AND THE SURFACE FRONT TO OUR SOUTH MOVES NORTH.
OVERNIGHT LOWS AROUND 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 PM MONDAY...
AS THE SURFACE HIGH CONTINUES TO RETREAT AND SURFACE LOW PRESSURE
MOVES NORTH ALONG THE COAST...THE SURFACE WARM FRONT SHOULD SLOWLY
MOVE NORTH. THE NAM IS FARTHER EAST WITH THE SURFACE LOW COMPARED TO
THE GFS...WHICH BRINGS WEAK SURFACE LOW PRESSURE RIGHT THROUGH
CENTRAL NORTH CAROLINA. THE GFS PATTERN IS SOMEWHAT CONCERNING...
WITH LOW LCL HEIGHTS ANTICIPATED ALONG WITH MODEST INSTABILITY BY
AFTERNOON...1000J/KG FROM THE 0-1KM LEVEL. HOWEVER...ITS 0-3KM
HELICITY FORECAST IS UNDER 100M2/S2 WITH ONLY MODEST 1000-500MB
LAPSE RATES AROUND 6C/KM AND 0-3KM SHEAR IS IN THE TEENS KNOTS AT
BEST. AFTER ANY MORNING LOW CLOUDS SHOULD START TO LIFT...BUFR
SOUNDINGS SHOW ENOUGH INSTABILITY FOR CU AND GENERALLY SKINNY CAPE
FOR SCATTERED SHOWERS AND THUNDERSTORMS. AS THE WARM FRONT IS
LOCATED BY THE GFS AND THE NAM MAINLY NORTH OF U.S. 64 BY
AFTERNOON...THE FORECAST LIFT OF THE NAM AND THE GFS IS HIGHEST FROM
THE TRIANGLE NORTH AND NORTHEAST. SHOULD THERE BE A STRONG
THUNDERSTORM...IT MAY BE THERE WHERE THE POTENTIAL IS HIGHEST.
DAYTIME HIGHS TUESDAY ARE ANOTHER CHALLENGE DEPENDING ON THE DEGREE
OF CLOUD COVER AND ESPECIALLY CU IN THE AFTERNOON...BUT WILL LEAN
TOWARD THE WARMER MAV GUIDANCE THOUGH NOT GOING QUITE THAT HIGH...
HIGHS 80 TO 85 IN THE TRIAD AND MID TO UPPER 80S ELSEWHERE.
TUESDAY NIGHT THE COLD FRONT STARTS TO MOVE INTO CENTRAL NORTH
CAROLINA FROM THE NORTHWEST. BUFR SOUNDINGS FROM BOTH THE NAM AND
THE GFS ACTUALLY FORECAST BRIEF LAYER WARMING BETWEEN 700MB AND
500MB BEFORE THE NAM IN PARTICULAR FORECASTS BRIEF COOLING IN THAT
LAYER ALONG AND AHEAD OF THE COLD FRONT. USING K INDICES AS A PROXY
FOR THE ACTUAL FRONT...AS THOSE VALUES GO QUICKLY NEGATIVE BEHIND
THE FRONT...THE FRONT SHOULD MOVE THROUGH THE TRIAD AROUND 06Z
WEDNESDAY AND THROUGH THE TRIANGLE AND JUST EAST OF U.S. 1 BY 12Z.
WILL RETAIN SOME CHANCES FOR PRECIPITATION UNTIL FRONTAL PASSAGE.
OVERNIGHT LOWS IN THE MID 60S IN THE TRIAD AND WITHIN A DEGREE OR
THREE OF 70 ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A TRANQUIL WEATHER PATTERN EXPECTED IN THE LONG TERM. TEMPERATURES
WILL REMAIN NEAR OR BELOW NORMAL.
A L/W TROUGH ANCHORED BY AN UPPER LEVEL LOW OVER ONTARIO/QUEBEC WILL
EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH FRIDAY. THE LEAD COLD
FRONT ASSOCIATED WITH THE TROUGH WILL EXIT OUR COASTAL PLAIN
COUNTIES WEDNESDAY MORNING. MODEL TREND HAS LEANED TOWARD A SLIGHTLY
FASTER EAST PROGRESSION. THUS HAVE TRIMMED THE BACKSIDE OF THE
SLIGHT POPS...KEEPING THE 20 PERCENT POPS CONFINED TO LOCATIONS
ALONG AND EAST OF I-95 AT 6 AM...WITH NEGLIGIBLE POPS BY 10 AM.
WESTERLY LOW LEVEL FLOW IN THE WAKE OF THE FRONT WILL AID TO
DIMINISH/DISSIPATE CLOUD COVERAGE IN THE MORNING...LEADING TO MOSTLY
SUNNY SKIES AREAWIDE BY EARLY AFTERNOON. IT SHOULD BE NOTICEABLY
LESS HUMID ACROSS MICH OF THE PIEDMONT BY EARLY-MID AFTERNOON...AND
INTO THE SANDHILLS AND COASTAL PLAIN LATE IN THE DAY. INITIAL SURGE
OF LOW LEVEL CAA WILL BE NEGATED SOMEWHAT BY DOWNSLOPE COMPONENT OF
LOW LEVEL FLOW AND MID-AUGUST SUN. MAX TEMPS IN THE MID 80S NW TO
UPPER 80S/AROUND 90 SE.
SOME DOUBT AS TO WHETHER NEAR SURFACE WINDS WILL BE ABLE TO DECOUPLE
AS A SECONDARY SFC FRONT WILL APPROACH FROM THE W-NW LATE WEDNESDAY
NIGHT-EARLY THURSDAY. IF ATMOSPHERE REMAINS WELL MIXED...MOST PLACES
SHOULD SEE MIN TEMPS NO LOWER THAN 60-65 DEGREES (NW-SE). IF WINDS
DECOUPLE...NORMALLY COLDER LOCATIONS MY DIP BELOW 60.
A CANADIAN HIGH PRESSURE SYSTEM AT THE SURFACE WILL BE CENTERED OVER
THE LOWER OH VALLEY AND TN VALLEY THURSDAY AND FRIDAY. THIS WEATHER
SYSTEM WILL MAINTAIN DRY CONDITIONS WITH TEMPS GENERALLY A FEW
DEGREES SHY OF NORMAL. THICKNESSES SUPPORT MAX TEMPS IN THE LOW-MID
80S THURSDAY...AND SOLIDLY IN THE MID 80S FRIDAY. BETTER CHANCE FOR
THE NEAR SURFACE WINDS TO DECOUPLE THURSDAY NIGHT. IF SKIES REMAIN
CLEAR...SHOULD SEE MIN TEMPS IN THE UPPER 50S-LOWER 60S. AIR MASS
MODIFICATION FRIDAY NIGHT SUGGEST MIN TEMPS IN THE LOW-MID 60S.
SURFACE HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY THEN SLOWLY
WEAKEN AS L/W TROUGH WEAKENS AND LIFTS NWD. THIS WILL ALLOW A WEAK
RETURN OF LOW LEVEL MOISTURE BY LATE SATURDAY AND MORE SO SUNDAY
INTO MONDAY. THIS WILL LEAD TO MIXTURE OF SUN/CLOUDS BUT ANY
CONVECTIVE ACTIVITY WILL BE ISOLATED AND CONFINED TO NEAR THE
SEABREEZE...AND EXITING OFF THE HIGHER TERRAIN OF WESTERN NC.
THREAT APPEARS TOO LOW TO MENTION A SLIGHT CHANCE POP ON SUNDAY BUT
ENOUGH MOISTURE/DESTABILIZATION SHOULD EXISTS BY MONDAY FOR SLIGHT
CHANCE IN VICINITY OF THE OUR SOUTHERN AND WESTERN COUNTIES.
AIR MASS WILL CONTINUE TO MODIFY WITH TEMPS RETURNING TO NEAR NORMAL
LEVELS SATURDAY THROUGH MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 155 PM MONDAY...
MOSTLY VFR CONDITIONS WILL OCCUR FOR THE REST OF THE AFTERNOON WITH
SCATTERED MVFR CONDITIONS IN SHOWERS...OR LOWER CLOUDS ESPECIALLY
TOWARD THE TRIAD. AN ISOLATED THUNDERSTORM IS POSSIBLE ESPECIALLY
TOWARD KFAY. OVERNIGHT...AS HIGH PRESSURE RETREATS TO THE NORTHEAST
AND A WARM FRONT STARTS TO LIFT NORTH...CEILINGS ARE ONCE AGAIN
EXPECTED TO LOWER. BY LATE TONIGHT...MANY LOCATIONS SHOULD HAVE AT
LEAST MVFR CEILINGS AND VISIBILITIES...IF NOT IFR CEILINGS. FOR THE
OVERNIGHT HOURS...THE BETTER CHANCE OF ANY PRECIPITATION SHOULD BE
TOWARD THE TRIAD AND PARTICULARLY KINT. AVIATION CONDITIONS SHOULD
LIFT THROUGH MVFR WITH VFR CONDITIONS ANTICIPATED BY THE END OF THE
18Z VALID TAF PERIOD.
TUESDAY AFTERNOON AND TUESDAY NIGHT...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS IN CENTRAL NORTH CAROLINA AHEAD OF A COLD FRONT THAT
SHOULD MOVE INTO CENTRAL NORTH CAROLINA OVERNIGHT TUESDAY. THE COLD
FRONT SHOULD BE MOVING THROUGH THE TRIAD AROUND 06Z WEDNESDAY AND
THROUGH THE TRIANGLE AROUND 12Z...PUSHING THROUGH THE COASTAL PLAIN
EARLY WEDNESDAY MORNING. THE PASSAGE OF THIS FRONT SHOULD END THE
HIGHER PROBABILITY OF SUB-VFR CONDITIONS FOR THE REST OF THE WORK
WEEK AND INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...WSS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
156 PM EDT MON AUG 11 2014
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY MOVE NORTHEAST AWAY FROM
THE REGION...AS A WARM FRONT SLOWLY MOVES NORTH OVER THE CAROLINAS
THROUGH THE DAY TUESDAY. A COLD FRONT FOLLOWS QUICKLY FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE MOVES OVER
MOST OF THE REGION FROM THE WEST WEDNESDAY AND WEDNESDAY NIGHT WITH
DRIER AIR FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM MONDAY...
THE LATEST VISIBLE IMAGERY SHOWS SOME GOOD LOW-LEVEL DRY AIR HAVING
WORKED ITS WAY ACROSS A LARGE SEGMENT OF CENTRAL NORTH CAROLINA
ESPECIALLY ALONG AND EAST OF ABOUT U.S. 1. PRECIPITATION HAS HAD A
HARD TIME MOVING EAST...AND TEMPERATURES HAVE WARMED NICELY TOWARD
KCTZ. THE RAP SEEMS TO HAVE BEEN TOO AGGRESSIVE IN MOVING THE 850MB
MOISTURE EAST AND IF THE LATEST RAP TRENDS AND VISIBLE IMAGES
CONTINUE...PEEKS OF SUN WILL BE PRESENT AT TIMES AT LEAST AS FAR
WEST AS U.S. 1. RADAR TRENDS ALSO SHOW DEEP CONVECTION DEVELOPING
ALONG THE NORTH CAROLINA SEA BREEZE SO STILL EXPECT SHOWERS TO
DEVELOP DURING THE AFTERNOON POSSIBLY MORE INSTABILITY DRIVEN AND
MOVING THEN TOWARD THE NORTHWEST IN THE LOW-LEVEL FLOW. HIGHEST
CHANCES FOR PRECIPITATION IN THE IMMEDIATE TRIAD.
TEMPERATURES REMAIN A CHALLENGE BUT THE LATEST FORECAST STILL SEEMS
TO HAVE A GOOD...BASIC HANDLE ON EXPECTED MAXIMUMS IN GENERAL.
RAISED MAXES TOWARD KCTZ AND NUDGED JUST SLIGHTLY LOWER TOWARD
KEXX...BUT LEFT THE REST INTACT FOR NOW ALTHOUGH MORE THIN SPOTS
COULD PROVIDE FOR WARMER READINGS SUCH AS TOWARD KFAY. LOWS TONIGHT
IN THE UPPER 60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR
PRECIPITATION IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD
INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 155 PM MONDAY...
MOSTLY VFR CONDITIONS WILL OCCUR FOR THE REST OF THE AFTERNOON WITH
SCATTERED MVFR CONDITIONS IN SHOWERS...OR LOWER CLOUDS ESPECIALLY
TOWARD THE TRIAD. AN ISOLATED THUNDERSTORM IS POSSIBLE ESPECIALLY
TOWARD KFAY. OVERNIGHT...AS HIGH PRESSURE RETREATS TO THE NORTHEAST
AND A WARM FRONT STARTS TO LIFT NORTH...CEILINGS ARE ONCE AGAIN
EXPECTED TO LOWER. BY LATE TONIGHT...MANY LOCATIONS SHOULD HAVE AT
LEAST MVFR CEILINGS AND VISIBILITIES...IF NOT IFR CEILINGS. FOR THE
OVERNIGHT HOURS...THE BETTER CHANCE OF ANY PRECIPITATION SHOULD BE
TOWARD THE TRIAD AND PARTICULARLY KINT. AVIATION CONDITIONS SHOULD
LIFT THROUGH MVFR WITH VFR CONDITIONS ANTICIPATED BY THE END OF THE
18Z VALID TAF PERIOD.
TUESDAY AFTERNOON AND TUESDAY NIGHT...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS IN CENTRAL NORTH CAROLINA AHEAD OF A COLD FRONT THAT
SHOULD MOVE INTO CENTRAL NORTH CAROLINA OVERNIGHT TUESDAY. THE COLD
FRONT SHOULD BE MOVING THROUGH THE TRIAD AROUND 06Z WEDNESDAY AND
THROUGH THE TRIANGLE AROUND 12Z...PUSHING THROUGH THE COASTAL PLAIN
EARLY WEDNESDAY MORNING. THE PASSAGE OF THIS FRONT SHOULD END THE
HIGHER PROBABILITY OF SUB-VFR CONDITIONS FOR THE REST OF THE WORK
WEEK AND INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1211 PM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE ACROSS EAST-CENTRAL INDIANA WILL DRIFT NORTHWARD
REACHING LAKE HURON BY TUESDAY MORNING. THIS WILL TAKE A WARM
FRONT NORTH ACROSS THE AREA TODAY AND A COLD FRONT TUESDAY. THE
LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS WORKING NORTH INTO THE AREA WITH
ADDITIONAL SHOWERS/THUNDERSTORMS DEVELOPING OVERHEAD TODAY.
OVER THE NEXT COUPLE OF DAYS A BROAD UPPER TROUGH WILL ENCOMPASS
THE EASTERN GREAT LAKES AND NEW ENGLAND. LOW PRESSURE ACROSS EAST
CENTRAL INDIANA WILL MOVE NORTH TOWARD LAKE HURON TODAY. MOISTURE
LEVELS ARE HIGH AND RAINFALL RATES COULD POTENTIALLY BE WILL BE AS
WELL. PRECIPITABLE WATER VALUES WILL NEAR 2 INCHES BY THIS
AFTERNOON. AREA IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
NO CHANGES MADE WITH THIS MIDDAY UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY/OUDEMAN
NEAR TERM...LOMBARDY/OUDEMAN
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
SEE FORECAST DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
THE NEXT COLD FRONT THAT IS FORECASTED TO MOVE INTO THE AREA THIS
EVENING IS CURRENTLY LOCATED IN NORTH TEXAS AND WILL CONTINUE TO
SLOWLY MOVE SOUTHWARDS THIS AFTERNOON. A HAND ANALYSIS OF 12Z
MAPS AT 850 AND 700MB THIS MORNING REVEALS TWO BOUNDARIES NEAR
KCLL WITH THE BEST MOISTURE JUST EAST OF THE AREA. AT 250MB A WEAK
UPPER LEVEL LOW WAS ANALYZED JUST SOUTH OF THE AREA WHICH IS
HELPING TO PROVIDE DIFFLUENT WINDS IN NORTHERN TEXAS THIS MORNING.
THE LOW IS FORECASTED TO CONTINUE TO PUSH SOUTH THIS AFTERNOON
ALLOWING THE UPPER LEVEL DIFFLUENCE ALSO TO SAG SOUTHWARDS. HIGH
RES HRRR AND RAP HAVE INITIALIZED THE BEST THIS MORNING AND FIRE
CONVECTION IN TWO AREAS. THE FIRST BEING A SEA BREEZE PUSHING
INLAND AND ALONG A COLD FRONT THAT IS PUSHING SOUTHWARDS. IT
SHOULD BE NOTED THE HRRR AND RAP FIRE WIDESPREAD CONVECTION IN OUR
NORTHERN ZONES THIS AFTERNOON. WAS TEMPTED TO GO LIKELY FOR POPS
BUT HAVE HELD OFF FOR NOW. FORECAST FOR THIS AFTERNOON REVEAL
PWATS NEAR 2.00" WITH K INDEX VALUES AROUND 40. FORECAST SOUNDINGS
ALSO SHOW AN INVERTED V THIS AFTERNOON. THIS COULD LEAD TO SOME
GUSTY WINDS IN STRONGER STORMS. IF CONVECTION GETS MORE WIDESPREAD
THIS AFTERNOON THIS WILL ALSO HOLD DOWN HIGH TEMPERATURES. FOR NOW
HAVE ONLY MADE MINOR TWEAKS TO GRIDS. 23
PREV DISCUSSION... /ISSUED 357 AM CDT MON AUG 11 2014/
DISCUSSION...
COOL FRONT SITUATED IN S OKLAHOMA EARLY THIS MORNING SHOULD MAKE
GRADUAL SWD PROGRESS & CLOSER TO N PARTS OF SE TX LATER THIS
EVENING. WITH AID OF DAYTIME HEATING EXPECT SHRA/TSTM COVERAGE
ALONG THE FRONT TO INCREASE THIS AFTN AND APPROACH N PARTS OF THE
CWA LATER IN THE DAY. FURTHER SOUTH & TOWARD THE COAST...ANTICIPATE
ISO/SCT PRECIP DEVELOPMENT ALONG THE SEABREEZE SIMILAR TO PAST
COUPLE DAYS.
THINGS GET INTERESTING THIS EVENING AND OVERNIGHT. REALLY NEED TO
KEEP AN EYE ON REGION BETWEEN THE SEABREEZE (OR REMNANTS OF) AND
THE CONVECTION DRIFTING IN FROM THE NORTH. SHOULD THESE EVENTUALLY
COLLIDE/MERGE...AND SEVERAL MODELS SUGGEST IT`S QUITE POSSIBLE...THREAT
OF LOCALIZED HEAVY RAINFALL REALLY INCREASES. GOES SOUNDER DATA SHOWING
PW`S AROUND 2.2" ACROSS THE REGION WHICH IS ABOUT 2 STANDARD DEVIATIONS
ABOVE NORMAL. WITH FAIRLY WEAK STEERING FLOW IN PLACE...LOCALIZED
BOUNDARY COLLISIONS WILL ENHANCE LIFT AND THREAT OF STORMS GOING
NEARLY STATIONARY INCREASES. ATTM HIGHER THREAT OF THIS OCCURRING
WILL PROBABLY BE SOMEWHERE ROUGHLY BETWEEN I-10 AND SOMERVILLE-
TRINITY LINE BETWEEN 7PM-MIDNIGHT.
FRONT AND ASSOCIATED PRECIP SHOULD MAKE GRADUAL SOUTHWARD
PROGRESS OVERNIGHT AND TOWARD THE COAST TUE. EXACTLY WHERE IT ENDS
UP IS IN QUESTION, BUT MAJORITY OF 00Z RUNS WITH EXCEPTION OF
NAM12 ACTUALLY PUSH IT *BRIEFLY* OFFSHORE LATE TUE NIGHT & WED
MORNING. SCT CONVECTION WILL REMAIN POSSIBLE ALONG/S OF THE FRONT.
LOWERED POPS ACROSS MOST AREAS NORTH OF I-10 TUESDAY AND INTO
MIDWEEK AS A CONSIDERABLY DRIER AIRMASS MOVES INTO THE REGION.
ANYONE UP FOR DEWPOINTS IN THE 50S/60S & HUMIDITIES 30-40%? HOW
ABOUT A FEW LOWS IN THE UPPER 60S IN THE NORTH HALF? LOOKING MORE
AND MORE LIKE A DECENT POSSIBILITY INTO MIDWEEK.
A GRADUAL RETURN BACK TO AUGUST REALITY EXPECTED DURING THE 2ND
HALF OF THE WEEK AND INTO THE WEEKEND AS THE FRONT WASHES OUT. ONSHORE
WINDS RESUME AS LEE SIDE PRESSURES FALL. MOISTURE LEVELS INCREASE
AGAIN WITH TYPICAL ISO SEABREEZE PRECIP. 47
MARINE...
LIGHT ONSHORE WINDS TODAY SHOULD BECOME MORE VARIABLE TUES/WEDS AS A
WEAK SFC FRONT SAGS INTO THE REGION. THIS BOUNDARY IS FCST TO SLOWLY
MAKE ITS WAY TO THE UPPER TX COASTLINE LATE MON/EARLY TUES...BUT NOT
EXPECTED TO MOVE INTO THE NEARSHORE WATERS AT THIS TIME. THE PROXIM-
ITY OF THIS SYSTEM SHOULD GENERATE PERIODS OF SHRAS/TSRAS FROM EARLY
TUES THROUGH WEDS. THIS BOUNDARY IS PROGGED TO WASH OUT THURS...WITH
THE NEXT STORM SYSTEM MOVING INTO THE STATE AND DEEPENING AROUND THE
SAME TIME. THIS SHOULD PRODUCE STRENGTHENING ONSHORE WINDS BY FRI...
AND ON INTO THE WEEKEND. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 74 96 70 96 / 50 50 10 10 10
HOUSTON (IAH) 95 75 94 73 95 / 30 50 30 20 20
GALVESTON (GLS) 93 81 89 80 92 / 20 50 40 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
355 PM CDT MON AUG 11 2014
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
THUNDERSTORMS DEVELOPED ALONG THE LAKE BREEZE CONVERGENCE OVER
EASTERN WI EARLY THIS AFTERNOON. THIS AREA OF STORMS ARE EXPANDING
BUT NOT MOVING...SO EXPECT AN INCH OF RAIN THERE THROUGH LATE
AFTERNOON.
MEANWHILE...VORTICITY ADVECTION WITHIN AN UPPER LEVEL TROUGH IS
DROPPING SOUTHEAST THROUGH WI THIS AFTERNOON. THE UPPER TROUGH WILL
CLOSE OFF AND STALL OVER SOUTHERN WI THIS EVENING. IT IS TAKING A
WHILE FOR CONVECTION TO DEVELOP ALONG THE COLD FRONT/ LEADING EDGE
OF VORT MAX/ OVER SOUTH CENTRAL WI...BUT THERE IS FINALLY A BROKEN
LINE DEVELOPING AT 230 PM NEAR MADISON AND THE DELLS THIS AFTERNOON.
I AM EXPECTING THIS LINE TO FILL AS IT GETS EAST OF MADISON AND
ESPECIALLY IN SOUTHEAST WI WHEN IT INTERACTS WITH THE LAKE BREEZE
BOUNDARY. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS.
PRECIPITABLE WATER VALUES ARE FAIRLY HIGH AROUND 1.5 INCHES. THE
UPPER LEVEL FLOW IS WEAK. THE SHEAR IS WEAK AND THERE IS 500 TO 1000
J/KG OF SURFACE BASED...TALL/SKINNY CAPE. THIS MEANS THE
THUNDERSTORMS WILL BE PULSY AND EFFICIENT RAIN PRODUCERS. WE CANNOT
RULE OUT SMALL HAIL WITH THE STRONGER STORMS...BUT THIS WILL BE THE
MINORITY. THE MAIN THREAT THIS AFTERNOON WILL BE PERIODS OF HEAVY
RAIN WHICH COULD CAUSE SOME URBAN FLOODING.
AFTER THE MAIN LINE OF STORMS MOVES THROUGH WITH THE
FRONT...CLEARING THE LAKESHORE AROUND 2-3Z...EXPECT ADDITIONAL
SHOWERS TO SPREAD BACK IN ACROSS SOUTH CENTRAL AND SOUTHEAST WI
DURING THE REST OF THE OVERNIGHT. THESE WILL BE ASSOCIATED WITH THE
UPPER TROUGH CLOSING OFF OVER THE WESTERN GREAT LAKES AND THE MAIN
VORTICITY MAX MOVING THROUGH SOUTHERN WI. THIS IS ALSO COINCIDENT
WITH UPPER DIVERGENCE IN THE LEFT EXIT REGION OF AN UPPER JET.
EXPECTING LOW CLOUDS TO SPREAD INTO SOUTHERN WI OVERNIGHT AS THE
RAIN SHOWERS RE-DEVELOP WITH THE UPPER LOW. THIS WILL KEEP TEMPS
WARMER...SO MIN TEMPS WILL BE AROUND 60 FOR MOST AREAS.
TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE UPPER TROUGH DOES NOT SHIFT EAST UNTIL LATER TUESDAY MORNING.
LINGERED SMALL CHANCE OF RAIN SHOWERS OVER SOUTHEAST WI THROUGH
MIDDAY. THE CLOUDS WILL LINGER LONGER IN THE EAST AS WELL...SO KEPT
MAX TEMPS IN THE LOWER 70S THERE...AND MID 70S INLAND.
THE DRY AIR WILL GRADUALLY WORK ITS WAY INTO SOUTHERN WI MIDDAY
TUESDAY. THE MODELS ARE NOT IN AGREEMENT ABOUT EXACTLY WHEN THIS
WILL HAPPEN.
EXPECTING GUSTY NORTH-NORTHWEST WINDS TUESDAY MORNING AS THE SURFACE
PRESSURE GRADIENT INCREASES AS LOW PRESSURE STRENGTHENS OVER LOWER
MICHIGAN.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
A LARGE POLAR TROUGH WILL RESIDE OVER FAR ERN ONTARIO AND WRN
QUEBEC CANADA THROUGH THURSDAY WITH NWLY FLOW ALOFT OVER WI. VERY
WEAK VORTICITY MAXIMUMS WILL LIKELY MOVE ACROSS THE AREA AND THE
MODELS DO DEPICT A VERY WEAK SFC TROUGH TO SHIFT SOUTH THROUGH THE
AREA WED AND WED NT. WEAK LOW LEVEL WARM ADVECTION IS EXPECTED
AHEAD OF THE TROUGH BUT THE COMBINATION OF A FAIRLY DRY AIRMASS
AND LITTLE TO NO LIFT SUPPORTS A DRY FCST. SCT-BKN MID LEVEL
CLOUDS ARE LIKELY WED AND WED NT BUT STILL ENOUGH SUNSHINE FOR
TEMPS TO WARM TO SEASONAL NORMALS ON WED. HIGH PRESSURE TO THEN
SETTLE OVER THE WRN GREAT LAKES FOR THU. DRY ENELY WINDS WILL
PREVAIL WITH PLEASANT TEMPS AND HUMIDITY.
.LONG TERM...
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE WILL MOVE EWD ON FRI WITH LGT SLY WINDS DEVELOPING.
HEAT AND HUMIDITY WILL INCREASE THROUGH THE WEEKEND INTO EARLY
NEXT WEEK AS A SHORTWAVE TROUGH AND SFC LOW APPROACHES. SLIGHT
CHANCES OF TSTORMS ARE FORECAST FOR THE WEEKEND WITH BETTER
CHANCES OF TSTORMS BY MONDAY.
&&
.AVIATION/00Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS IS DEVELOPING ALONG A COLD FRONT
IN SOUTH CENTRAL WISCONSIN AND WILL CONTINUE TO FILL IN AND EXPAND
AS IT TRACKS EASTWARD THROUGH SOUTHERN WI LATER THIS AFTERNOON INTO
THE EVENING. EXPECT MVFR CIGS/VSBYS WITH SHOWERS AND STORMS...WITH
SOME IFR VSBYS IN HEAVIER DOWNPOURS.
SHOWERS ARE EXPECTED TO RE-DEVELOP THIS EVENING AND LINGER THROUGH
TUESDAY MORNING AS THE SURFACE TROUGH/FRONT STALLS OVER SOUTHEAST
WI. THERE IS STILL UNCERTAINTY ABOUT HOW WIDESPREAD AND HOW FAR WEST
THESE WILL BE. EXPECT IFR STRATUS BEHIND COLD FRONT LATE TONIGHT AND
TUE MORNING AS WELL. LOOK FOR GUSTY NNW WINDS TUESDAY MORNING.
&&
.MARINE...
INCREASING NORTHERLY WINDS IN THE WAKE OF A COLD FRONT EARLY TUESDAY
MORNING WILL BUILD HIGH WAVES ON TUESDAY. A SMALL CRAFT ADVISORY
WAS ISSUED WITH THE 930 AM NSH UPDATE.
&&
.BEACHES...
A MODERATE TO HIGH SWIM RISK IS EXPECTED ON TUESDAY. GUSTY NORTHERLY
WINDS WILL BUILD HIGH WAVES DURING THE DAY TUESDAY. HIGHEST WAVES
WILL BE TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM TO 9 PM CDT TUESDAY FOR
LMZ644>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR LMZ643.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
234 PM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING SHORTWAVE TROUGH
SPINNING ACROSS NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. THE
11.12Z GFS/NAM AND 11.15Z RAP INDICATE DECENT FORCING IN ASSOCIATION
WITH SHORTWAVE TROUGH. THIS IS PRODUCING SHOWERS AND ISOLATED
THUNDERSTORMS MAINLY ACROSS EASTERN MINNESOTA AND MUCH OF
WISCONSIN PER LATEST MOSAIC RADAR.
MAIN CONCERNS TONIGHT ARE DIMINISHING TRENDS OF PRECIPITATION AND
LOW CLOUDS ACROSS THE FORECAST AREA. THE 11.12Z GFS/NAM INITIALIZE
SHORTWAVE TROUGH AND MOISTURE FIELDS WELL PER THE LATEST
VISIBLE/WATER VAPOR SATELLITE IMAGERY. THE 11.12Z GFS/NAM SHOW THE
FORCING TO EXIT THE FORECAST AREA AROUND 06Z TUESDAY AND ASSOCIATED
MOISTURE WITH SHORTWAVE TROUGH BY 12Z TUESDAY. HAVE TRENDED
PRECIPITATION CHANCES AND SKY COVER FOR THIS.
SURFACE RIDGE OVER THE DAKOTAS WILL BUILD INTO MINNESOTA AND
WESTERN WISCONSIN TUESDAY. SUBSIDENCE UNDERNEATH SURFACE HIGH WILL
ALLOW FOR DRY WEATHER CONDITIONS AND BELOW NORMAL TEMPERATURES
ACROSS THE FORECAST AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
WITH SURFACE RIDGE OVERHEAD ACROSS FORECAST AREA...THE 11.12Z
NAM/GFS ARE INDICATING AN INVERSION TO DEVELOP AFTER 06Z WEDNESDAY
PER BUFKIT SOUNDINGS. DUE TO WINDS AROUND 5 KNOTS THROUGH 1500
FEET. EXPECT THE FORMATION OF FOG OVER CENTRAL WISCONSIN AND IN
RIVER VALLEYS WEDNESDAY MORNING.
WEDNESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW ALOFT. THE
11.12Z GFS/NAM SHOW WEAK IMPULSE EMBEDDED IN THE NORTHWEST FLOW
ALOFT TO MOVE OVER PARTS OF THE FORECAST AREA. BUFKIT SOUNDINGS FROM
THE 11.12Z GFS/NAM INDICATE STEEP LOW LEVEL LAPSE RATES AND SOME
INSTABILITY ALOFT DURING THE DAY ACROSS CENTRAL WISCONSIN. THE
11.12Z NAM MORE ROBUST WITH THE INSTABILITY AND LOW LEVEL LAPSE
RATES THAN THE GFS. CANNOT RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM ACROSS CENTRAL WISCONSIN WEDNESDAY AFTERNOON. FOR
NOW...WILL CONTINUE WITH MENTION OF SPRINKLES OVER THIS AREA.
THE COMBINATION OF THE MAIN AXIS OF ISENTROPIC LIFT WEST OF FORECAST
AREA AND SHORTWAVE RIDGING BUILDING INTO THE REGION THURSDAY...WILL
PROVIDE DRY WEATHER CONDITIONS ACROSS THE AREA. HAVE REMOVED SMALL
PRECIPITATION CHANCES OVER THE WESTERN FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO
MONDAY. THE 11.12Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT BREAKING DOWN
UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES THIS WEEKEND AND
DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED
STATES. BIGGEST DIFFERENCE BETWEEN THE MODELS IS TIMING AND
PLACEMENT OF SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL
FLOW SATURDAY INTO MONDAY. THE 11.12Z GFS/ECMWF INDICATE DECENT
MOISTURE TRANSPORT AND CONVERGENCE WITH SHORTWAVE TROUGH PUSHING
INTO THE UPPER MIDWEST AND GREAT LAKES REGION SUNDAY INTO MONDAY.
DEPENDING ON TIMING/PLACEMENT OF SURFACE FEATURES/SHORTWAVE
TROUGH...PRECIPITATION CHANCES LOOK REASONABLE ACROSS MUCH OF THE
FORECAST AREA SATURDAY INTO MONDAY. HOWEVER...CONFIDENCE IS LOW ON
THE EXACT TIMING AND PLACEMENT OF THE SURFACE FEATURES/SHORTWAVE
TROUGHS TRACKING INTO THE UPPER MIDWEST AND GREAT LAKES REGION
DURING THIS PERIOD. TEMPERATURES FRIDAY INTO EARLY NEXT WEEK WILL
BE NEAR OR SLIGHTLY BELOW NORMAL ACROSS FORECAST AREA...WITH HIGHS
GENERALLY AROUND 80 DEGREES INTO THE LOWER TO MIDDLE 80S
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1231 PM CDT MON AUG 11 2014
LOW PRESSURE TRACKING OVER THE REGION THIS AFTERNOON WILL BRING A
FEW SHOWERS AND MVFR CONDITIONS TO THE AREA. THE SHOWERS WILL STAY
EAST OF KRST...IMPACTING KLSE THROUGH THE EARLY TO MID AFTERNOON
HOURS. THE CLOUDS WILL BE SLOW TO CLEAR LATE THIS AFTERNOON INTO
THIS EVENING AS HIGH PRESSURE GRADUALLY BUILDS IN FROM THE WEST.
PLAN ON MVFR CEILINGS LINGERING AT THE TAF SITES INTO THIS EVENING
WITH CLOUD BASES OF 1500 TO 2500 FT. THE CLOUDS WILL EVENTUALLY
CLEAR LATE THIS EVENING INTO THE OVERNIGHT HOURS. LOOK FOR THE
CLEARING TO MOVE INTO KRST AFTER 01Z THEN INTO KLSE AROUND 07Z. A
TIGHT GRADIENT OVER THE AREA BETWEEN THE LOW AND THE HIGH WILL
KEEP WINDS UP THROUGH THE NIGHT PROMOTING MIXING AND KEEPING
VALLEY FOG FROM FORMING AT KLSE. WINDS WILL INCREASE AGAIN
TOMORROW MORNING AS MIXING INCREASES. PLAN ON WIND SPEEDS OF 13 TO
15 KTS WITH GUSTS AROUND 22 KTS POSSIBLE. ALSO...SCATTERED CUMULUS
LOOK TO DEVELOP TOMORROW MORNING WITH CLOUD BASES IN THE 2-3 KFT
RANGE. THESE BASES SHOULD GRADUALLY RISE LATE IN THE MORNING INTO
THE AFTERNOON HOURS AS DEEPER MIXING OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1137 AM CDT MON AUG 11 2014
.UPDATE...
SUNSHINE OVER SOUTH CENTRAL WI WILL HELP BUILD SOME CAPE TO SUPPORT
THUNDERSTORMS THIS AFTERNOON ALONG A SURFACE TROUGH/COLD FRONT. KEPT
LIKELY POPS IN THE FORECAST UPDATE AND WILL CONTINUE TO REFINE THE
TIMING BASED ON THE HRRR AND RAP MODELS. THE FORECAST SOUNDINGS HAVE
A LITTLE DRIER PROFILE THAN PREVIOUS RUNS...WHICH WOULD MEAN PULSE-
TYPE THUNDERSTORMS RATHER THAN WIDESPREAD HEAVY RAIN. HOPEFULLY THE
STORMS WILL MOVE SLOW ENOUGH TO GIVE EVERYONE SOME MUCH-NEEDED RAIN.
AREAS WEST OF MADISON WILL END UP WITH THE LEAST AMOUNT OF RAIN.
THE SHOWERS AND THUNDERSTORMS ALONG THE FRONT WILL MARCH ALONG AT A
STEADY PACE THIS AFTERNOON WITH A FRONT AND BACK EDGE. THEN PERIODS
OF RAIN WILL ENSUE OVERNIGHT AS THE SURFACE AND UPPER TROUGH STALLS
OVER SOUTHEAST WI. I WILL WAIT FOR THE 12Z MESO MODELS TO COME IN
BEFORE MAKING A DECISION ABOUT HOW FAR WEST TO EXPAND THE
CHANCE/LIKELY POPS FOR THE OVERNIGHT/TUE MORNING PERIOD.
SUNSHINE IN WESTERN FORECAST AREA IS LEADING TO HIGHER TEMPS THAN
FORECAST...SO BUMPED UP THE MAX TEMPS A BIT.
&&
.AVIATION/18Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG A COLD FRONT
IN SOUTHWEST WISCONSIN AND TRACK EASTWARD THROUGH SOUTHERN WI LATER
THIS AFTERNOON INTO THE EVENING. EXPECT MVFR CIGS/VSBYS WITH SHOWERS
AND STORMS...WITH SOME IFR VSBYS IN HEAVIER DOWNPOURS.
SHOWERS ARE EXPECTED TO RE-DEVELOP THIS EVENING AND LINGER THROUGH
TUESDAY MORNING AS THE SURFACE TROUGH/FRONT STALLS OVER SOUTHEAST
WI. THERE IS STILL UNCERTAINTY ABOUT HOW WIDESPREAD THESE WILL BE.
EXPECT SOME IFR STRATUS BEHIND COLD FRONT LATE TONIGHT AND TUE
MORNING AS WELL.
&&
.MARINE...
INCREASING NORTHERLY WINDS IN THE WAKE OF A COLD FRONT EARLY TUESDAY
MORNING WILL BUILD HIGH WAVES ON TUESDAY. A SMALL CRAFT ADVISORY
WAS ISSUED WITH THE 930 AM NSH UPDATE.
&&
.PREV DISCUSSION... /ISSUED 451 AM CDT MON AUG 11 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
RADAR ESTIMATES AND RAIN GAGE DATA INDICATE 0.75 INCH TO 1.2 INCH
HAVE FALLEN OVER SE WISCONSIN WITH SHOWERS AND A FEW THUNDERSTORMS
THAT FORMED AHEAD OF SHORT WAVE THAT IS PUSHING EAST THROUGH NRN IL.
THIS AREA IS MOVING EAST WITH WAVE...BUT LINGERING SURFACE
TROUGHINESS WILL KEEP ENOUGH CONVERGENCE OVER AREA FOR SCATTERED
SHOWERS THROUGH MID-MORNING OVER THE FAR SE CORNER...THOUGH
POTENTIAL FOR HEAVY DOWNPOURS HAS ENDED FOR THE TIME BEING.
NOT MUCH CURRENTLY HAPPENING UPSTREAM AHEAD OF MAIN SHORT WAVE
TROUGH AND COLD FRONT...BUT MODELS ALL SHOW DEVELOPMENT WITH GROWING
INSTABILITY WITH DIURNAL HEATING AND INCREASING Q-VECTOR CONVERGENCE
AND FRONTOGENETIC RESPONSE TO SHORT WAVE AND FRONT. 0-6KM SHEAR
REMAINS WEAK SO LITTLE CHANCE FOR STRONG SUSTAINED UPDRAFTS NEEDED
FOR SEVERE...BUT SUFFICIENT CAPE AND PWS OF 1.5 TO 1.8 INCHES FOR
SOME DECENT DOWNPOURS. WILL NOT ISSUE A FLASH FLOOD WATCH AS DRY
CONDITIONS AND STORM MOTION IS SUFFICIENT TO PRECLUDE WIDESPREAD
FLOODING...THOUGH CLOSE MONITORING WILL BE NEEDED FOR POSSIBLE
LOCALIZED URBAN AND SMALL STREAM PROBLEMS.
MAIN PUSH OF PRECIPITATION MOVES EAST TOWARD CONSOLIDATING SURFACE
LOW OVER LOWER MICHIGAN...BUT LINGERING CYCLONIC FLOW AND MID-UPPER
FORCING KEEPS CHANCE POPS IN THE FAR EAST INTO TUESDAY MORNING.
TUESDAY - CONFIDENCE...MEDIUM
MID LEVEL TROUGH AXIS WILL BE ON THE WAY OUT OF SOUTHEAST WI
EARLY IN THE DAY. HOWEVER CYCLONIC FLOW LINGERS AND MODELS SHOW A
FAIRLY STRONG LOW WITH POTENTIAL FOR MORE WRAPAROUND THAN WAS
SUGGESTED IN PRIOR RUNS. MODELS SHOW PRECIP IN THE EASTERN CWA SO
HAVE PUT SOME MORNING POPS IN TO ACCOUNT FOR THIS POTENTIAL. LOW
LEVEL THERMAL TROUGH AND BREEZY CONDITIONS CAN BE EXPECTED WITH
THIS COOLER AIRMASS SETTLING IN. LOW LEVEL RH PROGS SUGGEST SOME
CLEARING AS THE DAY WEARS ON THOUGH POTENTIAL FOR CLOUD COVER TO
LINGER LONGER PER THE NAM GIVEN SOME CYCLONIC FLOW AND THERMAL
TROUGH.
WEDNESDAY THROUGH FRIDAY - CONFIDENCE...MEDIUM
ALL IN ALL THIS IS SHAPING UP TO BE A DRY PERIOD WITH HIGH
PRESSURE IN CONTROL. THE PROGS HAVE BEEN HINTING AT SOME LIGHT
PRECIP WEDNESDAY WITH A WEAK FRONT TRYING TO DROP INTO THE AREA.
THE SOUNDINGS LOOK CAPPED OFF WITH RESPECT TO A FAVORABLE PARCEL
TRAJECTORY...WHILE THE SUPERBLEND POPS ARE IN THE SINGLE DIGITS.
WILL STICK WITH THE DRY FORECAST FOR NOW BUT EURO AND GFS ARE
HINTING AT SOME SPOTTY LIGHT PRECIP. DEBATED ON ADDING SPRINKLES
BUT DECIDED TO LEAVE OUT.SO QUICK SHOT OF A RENEWED THERMAL TROUGH
THURSDAY WITH 925 TEMPS RETURNING TO NEAR 20C BY FRIDAY. GFS DOES
SHOW SOME LIGHT WAA QPF FRIDAY BUT IT LOOKS TOO QUICK AND IS SET
UP AS AN OUTLIER AT THIS POINT. WILL LEAN WITH THE CONSENSUS OF
THE GEM AND ECMWF WITH HIGH PRESSURE IN CONTROL.
SATURDAY AND SUNDAY - CONFIDENCE...LOW
ECMWF CONTINUES TO BE THE DRIEST SOLUTION WITH MORE PRONOUNCED
MID LEVEL RIDGING BUILDING UP BEFORE SHORTWAVE ENERGY ARRIVES
SUNDAY. MEANWHILE THE GFS AND TO A LESSER EXTENT THE GEM...SHOW A
FLATTER RIDGE WITH STILL SOME TIMING AND STRENGTH ISSUES. THE GFS
HAS BEEN CONSISTENTLY TRYING TO HAVE THE WETTER REGIME KICKING IN
SOONER WHILE THE ECMWF HAS BEEN CONSISTENTLY DRY. HOPEFULLY SOME
CONSENSUS COMES SOON BUT STILL A WAYS OFF. A LITTLE BETTER
AGREEMENT FOR PRECIP COME SUNDAY BUT STILL VARYING SOLUTIONS ON
DETAILS AND STRENGTH OF APPROACHING UPPER SUPPORT. FOR NOW WILL
RIDE WITH THE ALLBLEND POPS GIVEN THE DIVERGING MODEL SOLUTIONS.
AVIATION/12Z TAFS/...
SOME LIMITED AREAS OF IFR/LIFR CIGS IN THE FAR SOUTHEAST BEHIND
INITIAL ROUND OF SHOWERS AND THUNDERSTORMS. OTHERWISE EXPECT VFR
CONDITIONS THROUGH THE REST OF THE MORNING. LOOKING FOR AREA OF
UPSTREAM SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT TO
BECOME MORE WIDESPREAD...MOVING INTO WESTERN FORECAST AREA LATE
THIS MORNING/EARLY AFTERNOON AND REACHING THE EASTERN TAF SITES
MID-AFTERNOON. EXPECT MVFR CIGS/VSBYS WITH SHOWERS AND
STORMS...WITH SOME IFR VSBYS IN HEAVIER DOWNPOURS. SOME IFR
STRATUS ALONG AND JUST BEHIND COLD FRONT...BUT WILL KEEP POST-
FRONTAL CIGS AT MVFR LEVELS FOR NOW.
MARINE...INCREASING NORTH WINDS AS LOW PRESSURE CONSOLIDATES AND
DEEPENS OVER LOWER MICHIGAN WILL BUILD HIGH WAVES ON TUESDAY. A
SMALL CRAFT ADVISORY WILL BE LIKELY AS WAVE HEIGHTS UP TO 5 FEET
ARE EXPECTED WITH THE FAVORABLE FETCH.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM TO 9 PM CDT TUESDAY FOR
LMZ644>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR LMZ643.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1125 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 935 AM MDT MON AUG 11 2014
NO MAJOR WEATHER CONCERNS TODAY AS A HIGH AMPLITUDE UPPER-LEVEL
RIDGE CONTINUES TO BUILD INTO THE AREA. LINGERING MOISTURE ALOFT
WILL AID IN AT LEAST ISOLATED COVERAGE OF SHOWERS AND TSTMS OVER
THE MOUNTAINS...BUT OTHERWISE SOUTHEAST WYOMING SHOULD REMAIN ON
THE DRY SIDE. THE ONLY CHANGE TO THE INHERITED GRIDS CONCERNS PCPN
CHANCES OVER THE PANHANDLE. WATER VAPOR SATELLITE SHOWS CONTINUED
NORTHWEST FLOW ALOFT ON THE EAST SIDE OF THE RIDGE...ATOP A WEAK
SFC MOISTURE BOUNDARY ANALYZED FROM NORTH TO SOUTH ACROSS THE HIGH
PLAINS. GOOD LLVL MOISTURE WITH DEW POINTS AROUND 60F SUGGESTS POTENTIAL
FOR ISOLATED CONVECTION. ADDED SLIGHT CHANCE POPS FOR THOSE ZONES
AS THIS SETUP IS VERY SIMILAR TO YESTERDAY. HRRR COMPOSITE RADAR
REFLECTIVITY ALSO HINTS AT THIS. WILL NEED TO WATCH FOR A STRONGER
STORM OR TWO AS THE LATEST SPC MESOANALYSIS INDICATES AROUND
1000-1500 J/KG CAPES AS OF 15Z. COVERAGE SHOULD BE MINIMAL. ALL
OTHER ASPECTS OF THE FCST ARE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 415 AM MDT MON AUG 11 2014
A HIGH AMPLITUDE UPPER RIDGE WILL REMAIN OVER THE WESTERN CONUS TO
START THE WEEK...AND WILL SHIFT EAST TOWARD THE HIGH PLAINS BY
WEDNESDAY. CURRENT WATER VAPOR IMAGERY SHOWS A DRY DEFORMATION ZONE
OVER WYOMING WITH JUST A FEW MID/HIGH CLOUDS PASSING THRU OUR
NORTHERN ZONES ON THE WESTERN EDGE OF A STRONGER JET DIVING INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. PERSISTENT SURFACE HIGH
PRESSURE OVER THE CENTRAL PLAINS WILL MAINTAIN EAST-SOUTHEASTERLY
UPSLOPE FLOW ACROSS THE HIGH PLAINS OF WYOMING AND WESTERN
NEBRASKA TODAY. SOME OF THE MID LEVEL MOISTURE ASSOCIATED WITH THE
UPPER JET WILL REMAIN OVER THE REGION...AND COMBINED WITH THE
UPSLOPE FLOW...COULD SEE A FEW T-STORMS DEVELOP OVER THE MOUNTAINS
OF SOUTHEAST WYOMING THIS AFTERNOON. ANY STORMS THAT DO DEVELOP
WILL REMAIN WEAK AND WILL LIKELY PRODUCE VERY LITTLE RAINFALL AS
LI`S WILL BE ROUGHLY MINUS 1 UNDER WEAK WINDS ALOFT.
THE UPPER RIDGE AXIS WILL SHIFT EAST OVER THE ROCKIES FOR TUESDAY
WITH SOME WEAK MID LEVEL ENERGY AND MOISTURE MOVING UP FROM THE
SOUTHWEST TOWARD THE CWA. CONVECTION LOOKS TO REMAIN CONFINED TO THE
MOUNTAINS AND NEARBY VALLEYS AS THIS AREA WILL BE CLOSER TO THE
MOISTURE AND ENERGY...ALTHOUGH COVERAGE LOOKS TO REMAIN QUITE
ISOLATED STILL. TEMPS WILL TREND UPWARD AS THE UPPER RIDGE AXIS
SHIFTS OVERHEAD...WITH 700MB TEMPS INCREASING TO BE 12 TO 16C BY
TUESDAY AFTERNOON.
A STRONGER SHORTWAVE WILL APPROACH THE CWA FROM THE SOUTHWEST ON
WEDNESDAY AFTERNOON AND WILL DRAG WITH IT A DEEPER FETCH OF
SUBTROPICAL MOISTURE. THE LEE SIDE PRESSURE TROUGH WILL DEEPEN IN
ADVANCE OF THIS WAVE...IN ADDITION TO A SECOND WAVE MOVING THRU
MONTANA. CONVERGENCE WITHIN THE SFC TROUGH WILL BRING A BETTER
CHANCE FOR SHOWERS AND STORMS TO THE EASTERN PLAINS OF WYOMING AND
NEBRASKA WEDNESDAY AFTERNOON...WHILE GENERAL OROGRAPHIC CONVECTION
LOOKS A GOOD BET WITH SUPPORT FROM THE SHORTWAVE FEATURE. PWATS
WILL INCREASE TO ROUGHLY ONE INCH OR HIGHER BY WEDNESDAY
AFTERNOON...SO THIS ACTIVITY COULD PRODUCE MODERATE TO LOCALLY HEAVY
RAIN AT TIMES THROUGH THE AFTERNOON. WINDS AT THE JET LEVEL WILL
INCREASE TO BE 30-40 KT...BUT WILL STILL BE WEAK AT 500 MB AND
BELOW SO TO POTENTIAL FOR STORMS TO BECOME ORGANIZED LOOKS TO BE
MINIMAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM MDT MON AUG 11 2014
STARTING OFF WEDNESDAY NIGHT...MONSOONAL MOISTURE STILL OVER THE
AREA WHICH WILL INTERACT WITH A SHORTWAVE MOVING THROUGH THE UPPER
LEVEL RIDGE. BOTH THE GFS AND ECMWF PRETTY SIMILAR WITH SHOWERS
OVER THE SOUTHERN CWFA. SOME DIFFERENCES BETWEEN THE TWO FOR
THURSDAY.
LATEST ECMWF SHOWS SOME ENERGY COMING OFF THE CLOSED LOW OVER THE
PACIFIC NW FURTHER WEST THAN THE GFS FOR THURSDAY AFTERNOON. AS A
RESULT...MORE WIDESPREAD SHOWERS AND QPF ARE OVER THE WESTERN HALF
OF THE CWFA COMPARED TO THE GFS SOLUTION. PWATS OVER RAWLINS
APPROACHING 1 INCH WITH FORECAST STORM MOTIONS UNDER 5KT. OVER
HERE BY CHEYENNE...FORECAST PWATS 1.2 INCHES AND BY SIDNEY...1.5
INCHES. SHOULD BE VERY EFFICIENT RAIN PRODUCERS FOR THURSDAY
AFTERNOON. CONTINUED CHANCE POPS FOR MOST OF THE CWFA WITH BEST
CHANCES IN THE MOUNTAINS.
BIGGER DIFFERENCES FOR FRIDAY. GFS HAS US DRY FOR FRIDAY AFTERNOON
WHILE THE ECMWF BRINGS ANOTHER PIECE OF ENERGY OFF THAT CLOSED LOW
INTO THE AREA. IF THE ECMWF COMES TRUE...WE WILL BE LOOKING AT
HEAVY RAINFALL ONCE AGAIN FRIDAY AFTERNOON AND EVENING. KEPT SOME
LOW CHANCE POPS IN THE FORECAST FOR THIS TIME FRAME.
CLOSED LOW FINALLY MOVES THROUGH NORTHERN MONTANA FOR SATURDAY AND
WE WILL SEE THE RETURN OF DRY WEATHER TO WYOMING. COULD START TO
GET BREEZY SATURDAY AS GFS 700MB WINDS HIT 20KT SATURDAY
AFTERNOON AND 25KT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1120 AM MDT MON AUG 11 2014
A UPPER LEVEL RIDGE WILL LIMIT AFTERNOON CONVECTION TO THE HIGHER
TERRAIN OF SOUTHEAST WY. MOISTURE CONVERGENCE ALONG A NW-SE BOUNDARY
ACROSS NORTHWEST NE MAY TRIGGER ISOLATED TSTORMS BETWEEN 20Z AND
01Z IN AND AROUND CDR AND AIA. HAVE INSERTED VCTS AT THESE AERODROMES
FOR THIS POSSIBILITY. EXPECT SKIES TO BECOME CLEAR AFTER SUNSET.
WINDS WILL BE VARIABLE 10 KT OR LESS DURING THE NEXT 24 HRS.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT MON AUG 11 2014
MOSTLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY WITH ONLY A FEW
T-STORMS EXPECTED IN THE AFTERNOON FOR THE MOUNTAINS OF SOUTHEAST
WYOMING. THESE STORMS WILL BE WEAK AND SHOULD PRODUCE VERY LITTLE
RAINFALL. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTHERN AND WESTERN PORTIONS OF CARBON COUNTY MONDAY
AND TUESDAY AFTERNOONS...HOWEVER WINDS IN THIS AREA WILL FOR THE
MOST PART AVERAGE 10 MPH OR LESS. THE EXCEPTION WILL BE IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS WHERE WINDS WILL BE
VARIABLE AND GUSTY. INCREASING MONSOONAL MOISTURE AND STRONGER
UPPER LEVEL DISTURBANCES WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SHOWER COVERAGE DECREASES
LATE IN THE WEEK AS THE UPPER RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...JAMSKI
FIRE WEATHER...RJM