025
FXUS63 KLBF 071937
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
237 PM CDT TUE JUL 7 2020
SHORT TERM
(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 234 PM CDT TUE JUL 7 2020
ISOLATED THUNDERSTORM ACTIVITY IS EXPECTED THIS AFTERNOON AND
EVENING IN THE NORTHWESTERN NEBRASKA PANHANDLE. A BETTER CHANCE FOR
THUNDERSTORMS WILL COME WEDNESDAY AFTERNOON AND EVENING AS A SURFACE
COLD FRONT WILL MOVE INTO NEBRASKA LATER TONIGHT FROM THE NORTHWEST.
THE FRONT IS EXPECTED TO BE SLOW MOVING AND EVENTUALLY STALL OVER
CENTRAL INTO SOUTHWEST NEBRASKA WEDNESDAY AFTERNOON.
A SOUTHERLY LOW LEVEL JET WILL DEVELOP OVER WESTERN NEBRASKA THIS
EVENING. AT THE SAME TIME, A MODERATELY STRONG SHORTWAVE TROUGH
WILL TRACK NORTHEASTWARD FROM EASTERN WYOMING INTO THE DAKOTAS.
SURFACE BOUND CAPE VALUES ARE EXPECTED TO BE OVER 1000 J/KG, BUT
WILL REMAIN LARGELY CAPPED. SURFACE DEW POINTS WILL BE IN THE 40S TO
50S, WHICH WILL PROMOTE LARGE TEMPERATURE/DEW POINT SPREADS. ANY
STORM THAT DEVELOPS WILL BE HIGH BASED AND ISOLATED IN NATURE, THUS
POPS WILL ONLY REMAIN IN THE 20 TO 30 PERCENT RANGE. THE MAIN
CONCERN WITH THESE STORMS IS STRONG OUTFLOW WINDS.
THE POTENTIAL FOR STORM ACTIVITY IS MUCH GREATER ON WEDNESDAY. THE
FRONTAL BOUNDARY WILL EXTEND FROM SOUTHWEST TO NORTHEAST NEBRASKA ON
WEDNESDAY AFTERNOON. SURFACE CONVERGENCE ALONG THIS FRONT SHOULD
WEAKEN THE CAP SUFFICIENTLY AND PROMOTE THUNDERSTORM DEVELOPMENT.
THE COMBINATION OF STEEP MID LEVEL LAPSE RATES AND SURFACE DEW
POINTS IN THE 60S WILL YIELD CAPE VALUES OF 3000 J/KG. THE POOLING
OF MOISTURE AHEAD OF THE FRONT WILL LEAD TO PWAT VALUES OF 1.4 TO
1.8 INCHES WHICH COULD LEAD TO HEAVY RAINFALL. MAIN THREATS
ASSOCIATED THESE STORMS WILL BE LARGE HAIL, STRONG WINDS, AND HEAVY
DOWNPOURS. MODELS INDICATE STORM DEVELOPMENT BEGINNING IN THE MID TO
LATE AFTERNOON AND SHOULD MOVE OUT OF THE AREA WEDNESDAY EVENING
FAIRLY QUICKLY AS STORMS BECOME OUTFLOW DOMINATED AND DEVELOP
SOUTHEAST AWAY FROM THE AREA.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 234 PM CDT TUE JUL 7 2020
NEAR ZONAL FLOW ALOFT WILL BE IN PLACE ACROSS THE REGION THURSDAY.
A LARGE RIDGE OF HIGH PRESSURE WILL BE IN PLACE FROM WEST TX INTO
AZ, WITH OUR REGION ON THE SOUTHERN PERIPHERY OF THE STRONGER
WESTERLIES. A WEAK SHORTWAVE EMBEDDED WITHIN THE FLOW COULD HELP IN
THE DEVELOPMENT OF ISOLATED TSTMS LATE THURSDAY AFTERNOON AND
EVENING. CONFIDENCE IS RATHER LOW ON THIS OCCURRING THOUGH AS NO
REAL LOW-LEVEL FOCUS/BOUNDARY IN PLACE FOR CONVECTION TO DEVELOP. A
BETTER CHANCE APPEARS TO COME LATE FRIDAY AFTERNOON AND EVENING,
PRIMARILY ACROSS NORTHERN NEBRASKA WHERE A COLD FRONT WILL BE
APPROACHING DURING PEAK HEATING. A BIT STRONGER SHORTWAVE (COMPARED
TO THURSDAY) WILL ALSO BE MOVING ACROSS THE NORTHERN PLAINS. THE
SOUTHERN FLANK OF THIS WAVE WILL BE ACROSS NORTHERN NEBRASKA AROUND
00Z SATURDAY HELPING TO ENHANCE LIFT. A WEAK COLD FRONT CROSSES THE
AREA FRIDAY NIGHT ON THE BACKSIDE OF THE SHORTWAVE. NOT MUCH COOLER
BEHIND THE FRONT WITH MID 80S TO LOWER 90S STILL EXPECTED SATURDAY.
THE UPPER RIDGING THEN BEGINS TO BUILD NORTHWARD SUNDAY INTO THE
FIRST OF NEXT WEEK. THIS WILL LEAD TO MOSTLY DRY CONDITIONS AND
CONTINUED HOT WITH HIGHS IN THE 90S.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1224 PM CDT TUE JUL 7 2020
DRY WEATHER REMAINS ACROSS BOTH SITES THROUGH THE AFTERNOON. SOME
ISOLATED SHOWERS OR THUNDERSTORMS MAY IMPACT KVTN LATE THIS EVENING.
CONFIDENCE IN DEVELOPMENT AND TIMING IS TOO LOW TO PUT IN THE
PREVAILING FORECAST AT THIS TIME, BUT IT'S WORTH A MENTION HERE. DRY
WEATHER WILL THEN CONTINUE THROUGH WEDNESDAY MORNING. THE ONLY OTHER
MAJOR AVIATION CONCERN WILL BE THE CHANCE OF SOME LOW LEVEL WIND
SHEAR AT BOTH SITES AS THE LOW LEVEL JET INTENSIFIES OVERNIGHT.
LBF WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...MELTZER/TAYLOR
LONG TERM...TAYLOR
AVIATION...KULIK
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