Area Forecast Discussion
Issued by NWS North Platte, NE

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000
FXUS63 KLBF 211750
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1250 PM CDT MON JUL 21 2014

.SYNOPSIS...
ISSUED AT 309 AM CDT MON JUL 21 2014

ANALYSIS OF THE 07Z SURFACE DATA SHOWED LOW PRESSURE CENTERED OVER
WESTERN SOUTH DAKOTA WITH A TROUGH/DRY LINE EXTENDING THROUGH
WESTERN NEBRASKA AND NORTHWEST KANSAS TO SOUTHEAST COLORADO.
DEWPOINTS EAST OF THE DRY LINE WERE IN THE UPPER 60S TO LOWER
70S.

&&

.UPDATE...
ISSUED AT 1250 PM CDT MON JUL 21 2014

UPDATE EARLIER TO INCLUDE ISOLATED THUNDERSTORMS OVER SOUTHWEST IN
CENTRAL NEBRASKA. STALLED TROUGH COMBINING WITH VERY WARM TEMPS AT
THE SURFACE TO PRODUCE SOME HIGH BASED THUNDERSTORMS. ALREADY
SEEING A FEW LIGHTNING STRIKES...HOWEVER WITH SUCH A DRY LOWER
LEVEL...EXPECT LITTLE RAINFALL. INVERTED V SOUNDING DOES PRESENT A
GUSTY WIND THREAT AND WILL CONTINUE TO MONITOR THROUGH THE
AFTERNOON.

UPDATE ISSUED AT 643 AM CDT MON JUL 21 2014

LOCALIZED FOG HAS DEVELOPED IN PARTS OF CENTRAL AND NORTH CENTRAL
NEBRASKA. IT SHOULD LIFT OUT BY LATE MORNING. THE FORECAST HAS
BEEN UPDATED TO INCLUDE PATCHY FOG.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT MON JUL 21 2014

HEAT CONTINUES TO BE THE MAJOR ISSUE WITH THE FORECAST TODAY.
DEWPOINTS MAY DECREASE SOME WITH AS DRIER AIR ALOFT MIXES INTO THE
BOUNDARY LAYER. HOWEVER...THEY WILL PROBABLY DECREASE LESS THAN 5F.
WITH TEMPERATURES OF 95-100F AND DEWPOINTS OF 65-70F...HEAT INDICES
WILL GO 100 OR HIGHER. IN FACT...IN THE MORE HUMID AREAS OF CENTRAL
NEBRASKA WHERE DEWPOINTS OF 70 OR HIGHER ARE EXPECTED...HEAT INDICES
COULD BE AROUND 105F. HOWEVER...THEY SHOULD DECREASE TO 75F OR LOWER
BY LATE EVENING. IN THAT CASE...A HEAT ADVISORY COVERS THE HAZARD
ADEQUATELY.

SHORT TERM FORECASTS OF LOW LEVEL THETA-E INDICATE THE DRY LINE OVER
THE NEBRASKA PANHANDLE WITH SOME WEAK CONVERGENCE AND LIFTED INDICES
-1 TO -2C. WITH PRECIPITABLE WATER VALUES OF LESS THAN AN INCH AND
MEAN LAYER RELATIVE HUMIDITY OF 20-25 PERCENT IN THE LOWEST 2KM...
ONLY VERY ISOLATED THUNDERSTORMS ARE EXPECTED. FOR THE TIME
BEING...THEN...WE WILL KEEP THE PROBABILITY AT LESS THAN 15
PERCENT.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 309 AM CDT MON JUL 21 2014

A WEAK CANADIAN COLD FRONT WILL UNDERCUT THE STOUT
596DM UPPER LEVEL ANTICYCLONE ON TUESDAY...BRINGING SLIGHTLY COOLER
HIGH TEMPERATURES TO THE REGION.  AVAILABLE DETERMINISTIC GUIDANCE
HAS THE FRONT THROUGH THE CWA BY 18Z...WHICH FAVORS HIGHS IN THE
UPPER 80S TO LOWER 90S FOR OUR NORTH...BUT ONCE AGAIN NEAR 100...OR
AT LEAST THE UPPER 90S ALONG OUR SOUTHERN COUNTY WARNING BORDER.
BESIDES THE SLIGHTLY COOLER TEMPERATURES...THE FRONT COMES
THROUGH WITH LITTLE FANFARE.  A DRY TROPOSPHERE AND WARM
TEMPERATURES ALOFT WILL SQUELCH ANY MENTION OF STORMS ON TUESDAY.
SIMILAR HIGHS HOLD TRUE FOR WEDNESDAY...IN FACT READINGS MAY BE A
FEW DEGREES COOLER AS A EASTERLY TRAJECTORY OF THE LOWER
TROPOSPHERIC WIND DEVELOPS WITH THE CANADIAN SFC HIGH SETTLING EAST
OF THE MID MISSOURI VALLEY.  THERE REMAINS A  PRECIPITATION SIGNAL
LATE WEDNESDAY AFTERNOON AND EVENING ACROSS WESTERN NEBRASKA AS A
RIDGE RIDING DISTURBANCE INTERACTS WITH THE EASTERLY UPSLOPE AND A
STATIONARY BOUNDARY DRAPED OVER THE PANHANDLE.  INCREASINGLY RICH
THETA-E AND SUBSEQUENT RETURN MOISTURE WILL BE DRAWN NORTH ATOP THE
HIGH PLAINS WITH A BRIEF WEAKNESS IN THE UPPER LEVEL TEMPERATURES
SHOWN.  THE ATMOSPHERE SHOULD BE SUFFICIENTLY CAPPED FOR MUCH OF THE
REGION...BUT CANNOT RULE OUT A FEW STORMS...ESPECIALLY WEST....WILL
MAINTAIN SLIGHT CHANCES INTO THURSDAY MORNING FOR LOCATIONS
GENERALLY WEST OF A KOGA TO KANW LINE.  THURSDAY TEMPERATURES SHOULD
WARM A FEW DEGREES...ESPECIALLY ACROSS WESTERN NEBRASKA AS THE UPPER
LEVEL ANTICYCLONE AMPLIFIES BRIEFLY OVER THE NORTHERN/CENTRAL
PLAINS.  HOWEVER AN PAC NW/SOUTHERN CANADA UPPER LEVEL LOW WILL
QUICKLY BREAK DOWN THE RIDGE AND EFFECTIVELY FORCE A COLD FRONT
THROUGH THE CWA ON FRIDAY.  AT THIS POINT IN TIME GREATER SUPPORT
FOR PRECIPITATION LIES TO OUR NORTH AND EAST...WIDESPREAD STORMS ARE
NOT ANTICIPATED FRIDAY.  INTO THE WEEKEND...THE UPPER LEVEL
ANTICYCLONE RE-ENERGIZES ATOP THE GREAT BASIN AND ROCKY MOUNTAIN
WEST...EFFECTIVELY PROVIDING NORTHWEST FLOW FOR THE PLAINS AND A
REPRIEVE FROM THE TRIPLE DIGIT HEAT.  IN FACT HIGH TEMPERATURES MAY
FALL BELOW SEASONAL NORMS FOR MUCH OF THE CWA THIS WEEKEND.  RAIN
CHANCES WILL REMAIN ISOLATED AT BEST THIS WEEKEND AND EARLY NEXT
WEEK...APPRECIABLE LOW LEVEL MOISTURE IS LACKING AND TEMPERATURES
ALOFT SHOULD REMAIN SLIGHTLY ON THE WARM SIDE...CAPPING MOST
CONVECTIVE DEVELOPMENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CDT MON JUL 21 2014

A FEW ISOLATED THUNDERSTORMS ACROSS SOUTHWEST NEBRASKA THIS
AFTERNOON AS A WEAK BOUNDARY COMBINES WITH VERY WARM SURFACE
TEMPS TO PRODUCE MARGINAL INSTABILITY. THUNDERSTORMS COULD IMPACT
THE KLBF TERMINAL...ALTHOUGH CONFIDENCE IS LOW AT THIS TIME SO NO
MENTION AT THIS TIME. LATEST RADAR/SATELLITE LOOP SHOWS THE KLBF
TERMINAL ON THE NORTH SIDE OF THE ACTIVITY. CAP STRENGTHENS
TONIGHT AND ACTIVITY EXPECTED TO DISSIPATE. FURTHER NORTH...FOR
KVTN TERMINAL...CAP IS EXPECTED TO HOLD. WINDS BECOME NORTHERLY
OVERNIGHT INTO TOMORROW MORNING AS A WEAK COLD FRONT MOVES ACROSS
THE AREA.

&&

.FIRE WEATHER...
ISSUED AT 309 AM CDT MON JUL 21 2014

THE VERY WARM TEMPERATURES IN CENTRAL AND WESTERN NEBRASKA THIS
AFTERNOON WILL REDUCE THE RELATIVE HUMIDITY TO 15-20 PERCENT IN THE
WESTERN SANDHILLS AND EASTERN PANHANDLE. WIND IS EXPECTED TO REMAIN
FAIRLY LIGHT AT 10-18 MPH SO CRITICAL FIRE CONDITIONS ARE NOT
EXPECTED.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ005>010-025>029-
037-038-059-070-071.

&&

$$

UPDATE...MASEK
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...JACOBS
AVIATION...MASEK
FIRE WEATHER...SPRINGER



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