FXUS63 KLBF 101947

Area Forecast Discussion
National Weather Service North Platte NE
247 PM CDT Sat Jun 10 2023

Issued at 244 PM CDT Sat Jun 10 2023

Key Messages:

- The threat of locally heavy rainfall which could produce
  flooding in some areas continues tonight through Tuesday.

- Winds aloft will become strong Thursday and Friday and
  thunderstorms are in the forecast. The potential for severe
  storms these days is being monitored.


.SHORT TERM...(This evening through Sunday night)
Issued at 244 PM CDT Sat Jun 10 2023

The models are slowing up the southward progression of a wet cold
front across nrn Nebraska this evening and overnight. The blended
forecast which includes the NAM, RAP and HRRR is in place and this
continues the rain chances across swrn Nebraska during the day

Satellite shows a very weak MCV circulation near Thedford and radar
shows a second across nrn Nebraska near Valentine. The system near
Valentine activated this morning and produced flooding. Both systems
could become the focus for locally heavy rainfall and flooding as
they move very slowly southeast along the front this afternoon and
tonight. As noted by WPC, winds aloft are very weak, less than 10
kt, but it`s worth noting the warm air advection is neutral and the
h850 moisture advection is from the north. Nonetheless, moisture
advection will peak this afternoon and this evening and then fall
off overnight.

The cold front will become stationary along the Colo Front range
tonight and remain anchored Sunday. Daytime heating and weak
dynamics emanating from the approach of an upper low off the srn CA
coast should set off additional storm activity across sern WY and
ern Colo Sunday which could drift into swrn Nebraska. The bulk of
this rain will remain across Colo and KS.

.LONG TERM...(Monday through Saturday)
Issued at 244 PM CDT Sat Jun 10 2023

The upper low off the srn CA coast moves east and opens up across
WY and Colo Monday and Tuesday presenting addition shower and
thunderstorm chances across swrn Nebraska. The models continue to
show the bulk of this rain across the cntl high Plains west of
swrn Nebraska, but PWAT will remain an inch or higher and winds
aloft will remain very weak. The weak winds and moisture could
support the development of a locally heavy rain center across swrn
Nebraska. WPC has highlighted the high Plains and a small portion
of swrn Nebraska for excessive rainfall Monday and Tuesday for
this reason.

Rain chances diminish Wednesday as the upper low shears out and
moves east through KS. The models are then in good agreement
developing a belt of westerlies Thursday which amplify and become
strong from the northwest Friday and beyond. Thunderstorms chances
ramp up Thursday for a disturbance moving across the cntl Rockies.
The thunderstorm chance Friday is lower with a just weak disturbance
moving east out of WY. Severe weather could develop both days but it
appears the forcing Thursday is stronger and would present the best
opportunity for strong or severe storms.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1245 PM CDT Sat Jun 10 2023

Biggest challenge is timing/location of slow moving convection as
cold front moves south across central and western Nebraska. KVTN
has been in thunderstorms with occasionally heavy rain and
IFR/LIFR conditions this morning and expect this will be the case
into this afternoon, though to a somewhat lesser extent. Activity
will not push southward and finally clear of KVTN until well
after sunset and will use timing of 03Z here. Conditions are less
certain at KLBF with guidance giving conflicting signals as to
whether KLBF sees active convection or just VCTS. Since there are
currently no storms near KLBF, will go with VCTS and amend as
necessary based on radar trends this afternoon. Convection will
push south and clear of KLBF toward daybreak and will use a timing
of 08Z here.

Once convection passes TAF sites expect IFR/LIFR stratus to become
established and persist into Sunday morning. Conditions may
improve by the end of the valid period but timing is uncertain so
will not indicate a return to VFR with this TAF package.

Winds will be erratic as gusts from thunderstorm outflows move
across the region. Expect a general northwest direction then
veering to a northerly direction as convection exits the region.





NWS LBF Office Area Forecast Discussion