Area Forecast Discussion Issued by NWS Goodland, KS
000
FXUS63 KGLD 220821
AFDGLD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
221 AM MDT WED MAY 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 220 AM MDT WED MAY 22 2013
500 MB RIDGE WILL MOVE OVER COLORADO TODAY PLACING THE FORECAST AREA
IN DRY NORTHWEST FLOW ALOFT. MODEL THICKNESS PROGS SHOW A 60-90
METER RISE...AND 850 MB TEMPERATURES WILL REACH 20 DEGREES CELSIUS
SOUTHWEST OF A LINE FROM AKRON COLORADO TO SCOTT CITY KANSAS. WITH
ABUNDANT SUNSHINE...EXPECT MAXIMUM TEMPERATURES TO REACH INTO THE
MID 70S MOST LOCATIONS.
EXPECT CONVECTION TO DEVELOP OVER THE COLORADO FRONT RANGE THIS
AFTERNOON. THE QUESTION IS WHETHER ANY OF THIS WILL MOVE FAR ENOUGH
EAST TO IMPACT THE FORECAST AREA. GFS BRINGS A WEAK SHORT/WAVE
TROUGH THROUGH THE RIDGE BETWEEN 00Z-06Z TONIGHT...AND DEPICTS A
DECENT AMOUNT OF PRECIPITATION. THE NAM SHOWS NO WAVE AND IS DRY.
06Z WATER VAPOR SHOWS A WEAK WAVE MOVING ACROSS NEVADA...BUT WITH
THE AMOUNT OF RIDGING...THINK SUBSIDENCE WILL PREVAIL TONIGHT. ALSO...
EXPECT THE AIR MASS TO BE RELATIVELY STABLE. THE END RESULT...WILL
KEEP THE FORECAST DRY.
SURFACE HIGH WILL GRADUALLY MOVE OVER NEBRASKA TONIGHT. SURFACE WINDS
REALLY DO NOT VEER TO THE SOUTHEAST THROUGH 12Z...AND SO MOISTURE
ADVECTION WILL NOT BE MUCH OF AN ISSUE TONIGHT. HOWEVER...EXPECT
SURFACE DEW POINT DEPRESSIONS TO APPROACH ZERO LATE TONIGHT.
THIS...COMBINED WITH EAST UPSLOPE FLOW...WILL PRODUCE SOME STRATUS/FOG.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 220 AM MDT WED MAY 22 2013
THURSDAY...TEMPERATURE FORECASTS WILL BE COMPLICATED DUE TO THE
POSSIBILITY OF STRATUS/FOG IN THE MORNING. ALSO...SURFACE HIGH WILL
ADVECT SOME COOLER AIR ACROSS THE AREA. SO...EXPECT TEMPERATURES TO
RETURN TO THE 60S. THE COOLER AIR WILL ALSO CONTRIBUTE TO A STABLE
AIR MASS...SO EXPECT ANY AFTERNOON CONVECTION TO BE LIMITED AT BEST.
THURSDAY NIGHT...SURFACE WINDS WILL BECOME SOUTHEAST...AND WILL
FINALLY ADVECT HIGHER DEW POINTS ACROSS THE AREA. EXPECT STRATUS AND
FOG TO FORM...ESPECIALLY SOUTH OF INTERSTATE 70...AFTER MIDNIGHT.
GFS IS ALSO DEVELOPING SOME ELEVATED CONVECTION IN A WARM AIR
ADVECTION AREA ACROSS SOUTHWEST KANSAS. THERE WILL BE LIMITED
INSTABILITY...AROUND 200 J/KG...BUT ENOUGH TO MENTION SOME CONVECTION.
FRIDAY AND FRIDAY NIGHT...STRATUS/FOG WILL OCCUR EARLY FRIDAY MORNING...
BUT WILL CLEAR BY THE AFTERNOON. THE AIR MASS WILL BECOME UNSTABLE
AFTER 18Z WITH PROGGED MIXED LAYER CAPES BETWEEN 1000-1500 J/KG. A
DRY LINE WILL DEVELOP OVER EASTERN COLORADO DURING THE DAY. AS IT
PROGRESSES EAST...CONVECTION MAY DEVELOP. MODEL SOUNDINGS SHOW AN
ELEVATED MIXED LAYER WILL OCCUR AROUND 700 MB. EXPECT THE CAP TO
BREAK AS WARM AIR ADVECTION IN THE BOUNDARY LAYER INCREASES. THE
NOCTURNAL LOW LEVEL JET DEVELOPS FRIDAY NIGHT...AND THIS LENDS
BETTER CONFIDENCE FOR CONVECTION ESPECIALLY EAST OF HIGHWAY 83.
FOR THE REST OF THE PERIOD...SOUTHWEST FLOW ALOFT WILL CONTINUE ACROSS
THE AREA AS AN UPPER LOW PERSISTS OVER THE PACIFIC NORTHWEST. THE
ECMWF NOW AGREES WITH GFS IN PLACING UPPER RIDGE AXIS JUST EAST OF
OUR FORECAST AREA SO CONFIDENCE IS A LITTLE HIGHER IN DAILY
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE FIRST
PART OF NEXT WEEK. WEAK SHORTWAVES EMBEDDED WITHIN THE FLOW ALOFT
COULD ENHANCE CONVECTIVE COVERAGE BUT TIMING OF THESE IS DIFFICULT
THIS FAR OUT. GFS AND ECMWF BOTH SHOW A MORE PROGRESSIVE PATTERN
EVOLVING BY EARLY NEXT WEEK. A UPPER LEVEL TROUGH APPROACHES THE
AREA BY LATE TUESDAY BRINGING THE POTENTIAL FOR BETTER PRECIPITATION
CHANCES AND ORGANIZED CONVECTION BY MID WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1106 PM MDT TUE MAY 21 2013
IN THE WAKE OF THE EXITING LOW PRESSURE SYSTEM...HIGH PRESSURE AT
THE SURFACE BEGINS TO MOVE INTO THE CENTRAL HIGH PLAINS REGION
FROM THE NORTHERN PLAINS WHILE THE RIDGE AXIS ALOFT MOVES FROM THE
ROCKIES TO THE HIGH PLAINS. MID TO HIGH CLOUDS SHOULD DIMINISH
THROUGH THE OVERNIGHT HOURS AND DURING THEY DAY ON WEDNESDAY AS A
RESULT. HOWEVER...WITH THE RETURN FLOW AROUND THE SURFACE HIGH
PRESSURE AREA PRODUCING UPSLOPE FLOW ACROSS THE REGION LATE IN THE
TAF PERIOD WEDNESDAY EVENING...THERE IS THE POSSIBILITY OF LOW
CLOUDS AND SOME AREAS OF REDUCED VISIBILITY DEVELOPING IN THE LOW
LEVEL EASTERLY FLOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MENTZER
LONG TERM...BOWERS
AVIATION...LOCKHART