685 
FXUS63 KUNR 302347
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
547 PM MDT Thu May 30 2019

.DISCUSSION...(This Evening Through Thursday)
Issued at 250 PM MDT Thu May 30 2019

Current surface analysis shows high pressure southwest of the 
area, with a cold front and area of low pressure across south 
central Canada. Upper level analysis shows ridging now covers much
of the northern and central Plains, with low pressure over 
southern OR slowly sliding south into CA. Skies are mostly sunny 
across much of the area, though hazy skies persist as smoke from 
wildfires in Alberta linger over the region. A couple of showers 
have tried to develop over the northern Black Hills this 
afternoon, otherwise dry conditions are in place. Temps are in the
70s across much of the plains, with 60s across the Black Hills. 
Winds are becoming southerly from west to east across the area. 

A fairly stagnant pattern will remain in place across the western 
and central US over the next few days. The best chances for showers 
and storms through the weekend will be over the Black Hills, 
especially during the afternoon hours, as terrain induced showers 
develop. A weak shortwave will likely bring more widespread chance 
for showers and a few storms late Friday into Friday night. The 
combination of CAPE and shear are not very favorable for severe 
storms on Friday, but small hail and gusty winds are a possibility 
with any stronger storms late in the day. 

The possibility for stronger storms will increase some over the 
weekend, mainly from northeast WY into the Black Hills, as a cool 
front stalls out across southeast MT to the Black Hills area. Lack 
of upper level forcing will likely keep main pcpn chances limited to 
the Black Hills, at least on Saturday. As ridge shifts a bit to the 
south and east on Sunday, chances should spread more onto the plains 
of northeast WY and western SD. Temperatures will be a bit cooler 
over the area, especially on Saturday, with highs mostly in the mid 
60s to mid 70s.   

As ridge flattens out over the Plains early next week, this will 
allow weak shortwave energy from the stalled out CA low to move 
across the Rockies and into the region at times. The front over the 
area this weekend will slowly move east as a warm front early in the 
week, with warm conditions Monday into Tuesday. A cold front and 
stronger shortwave could bring a good chance of thunderstorms 
Tuesday afternoon and evening, but timing and strength of this 
system is uncertain at this point. Near zonal flow midweek should 
keep temps near seasonal averages, with the possibility of at least 
isolated showers and storms. 

&&

.AVIATION...(For the 00Z TAFS Through 00Z Friday Evening)
Issued At 547 PM MDT Thu May 30 2019

VFR conditions are expected throughout most of the TAF period. A
few SHRA/TSRA are possible this evening and again Friday afternoon,
which could lead to localized MVFR conditions.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION...26
AVIATION...Sherburn