000 
FXUS65 KCYS 251410 CCA
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
220 AM MDT SUN MAY 25 2008

.SHORT TERM...SUNDAY THROUGH MONDAY NIGHT.
TEMPERATURES WILL RETURN TO SLIGHTLY ABOVE NORMAL VALUES TODAY WITH 
ONLY A SLIGHT CHANCE FOR A BRIEF SHOWER THIS MORNING OVER THE
SOUTHERN PORTION OF CARBON COUNTY. ELSEWHERE...NO PRECIPITATION 
IS EXPECTED TODAY. THE UPPER LEVEL TROUGH WILL REORGANIZE ALONG
THE PACIFIC COAST AND THIS WILL LEAD TO INCREASED HEIGHTS AND THE
PRESENCE OF AN UPPER RIDGE OVER THE AREA. JET STREAM ENERGY
ROUNDING THE BASE OF THE TROUGH WILL CREATE SURFACE PRESSURE FALLS
ALONG THE COLORADO FRONT RANGE THIS AFTERNOON. THIS WILL COMBINE
WITH SURFACE HIGH PRESSURE TO THE NORTH BENEATH THE UPPER RIDGE.
THIS WILL INDUCE A SURFACE PRESSURE GRADIENT SUFFICIENT ENOUGH TO
CREATE A WIND SHIFT OR WEAK FRONTAL PASSAGE SOUTHWEST-WARD ACROSS
THE FORECAST AREA THIS EVENING. THE RESULTING UPSLOPE FLOW WILL
CONTINUE TO BE PRESENT THROUGH MONDAY NIGHT...AS THE STRONGEST
DISTURBANCE ALOFT ROTATES AROUND THE BASE OF THE UPPER TROUGH AND
ACROSS THE AREA MONDAY. INSTABILITY MONDAY AFTERNOON AND EVENING
APPEARS TO BE LIMITED OVER THE EASTERN HALF OF THE FORECAST
AREA...WITH ANY THUNDERSTORMS EXPECTED TO BE LIMITED TO AREAS WEST
OF THE LARAMIE RANGE.

.LONG TERM...TUESDAY THRU SATURDAY...CHANCE FOR MAINLY SHOWERS WILL 
PERSIST MAINLY TUESDAY MORNING WITH LOW LEVEL UPSLOPE FLOW BUT BY 
AFTERNOON SFC FLOW BECOMES MORE PARALLEL TO MTNS THUS UPSLOPE WILL 
BE MINIMAL AND INSTABILITY ESSENTIALLY NIL.  UPPER FLOW BACKS A BIT 
WEDNESDAY AND SOME INCREASE IN INSTABILITY COULD SET OFF ISOLATED
AFTN AND EVENING TSTRMS MAINLY OVER THE MTNS.  SLIGHTLY BETTER 
CHANCE FOR TSTRMS EAST OF THE MTNS THURSDAY AS IMPULSE INTERACTS 
WITH DEVELOPING LEE TROF OVER THE HIGH PLAINS ALONG WITH WARM 
TEMPERATURES.  MAINLY DRY FRIDAY AND SATURDAY ALONG WITH SEASONABLE 
TEMPERATURES AS UPPER FLOW BECOMES MORE ZONALLY ORIENTED AND SFC 
FRONT SHIFTS EAST OF THE CWA TAKING BETTER INSTABILITY WITH IT.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED WITH JUST A FEW BRIEF MORNING SHOWERS 
OVER THE HIGHER TERRAIN THIS MORNING.

&&

.HYDROLOGY...
WILL ALLOW THE FLOOD WARNING TO CONTINUE FOR THE NORTH PLATTE
RIVER IN CONVERSE COUNTY...AS LATEST REPORTS CONTINUE TO INDICATE
THE NORTH PLATTE RIVER REMAINING SLIGHTLY ABOVE FLOOD STAGE NEAR
ORIN. EXPECTATIONS ARE THAT THE RIVER WILL RETURN TO BELOW FLOOD
STAGE AT 600 AM MDT THIS MORNING...BUT WILL NOT CANCEL THE
WARNING UNTIL UPCOMING OBSERVATIONS INDICATE THE EXPECTED
CONTINUATION OF DECREASING LEVELS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...A FLOOD WARNING CONTINUES FOR THE NORTH PLATTE RIVER NEAR 
     ORIN IN CONVERSE COUNTY...WYC009...UNTIL NOON MDT TODAY.
NE...NONE.

&&

$$

SHORT TERM/AVIATION...SJC
LONG TERM....RE