316
FXUS63 KUNR 300701
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
101 AM MDT Mon Sep 30 2024

.KEY MESSAGES...

-Much cooler with strong gusty winds today, especially this
 morning

-Continued dry this week with above normal temperatures
 continuing most days

-Critical to near critical fire weather conds most days this week

&&

.DISCUSSION...(Today Through Sunday)
Issued at 1258 AM MDT Mon Sep 30 2024

Continued active northern stream flow will support periodic dry
low pressure systems through the region this week. The strongest
of these systems will move through the region this morning,
supporting a strong cold front into the area with gusty northwest
winds. Winds will shift NW and increase with gusts over 50 mph
most places early this morning. Locations from far NW SD to just
east of the Black Hills will see gusts over 60 mph for a period,
with some gusts up to 70 mph. Have upgraded to a high wind warning
for this. Otherwise, the wind adv remains in effect for the rest
of the SD plains. The strongest winds will be this morning with
winds slowly coming down through the afternoon. Much cooler conds
today, with temps falling into the 30s tonight most areas, with
some 20s likely in a few low lying areas as high pressure builds
into the region. This will allow for some frost. Will defer any
frost/freeze headlines to the day shift. Warmer conds expected
Tues and Wed as WAA ensues ahead of the next low pressure system.
It will also become breezy Tues as southerly return flow increases
behind the sfc high. Cool front will move through Wed, knocking
temps back down Thurs. However, it will warm back up for the end
of the week as another impulse will ride fast flow to the north,
bringing undulating temps and breezy weather. The degree of
warming and cooling will hinge on the track of each system.
Unfortunately, each system will be dry with little to no available
moisture, supporting a dry forecast through the period as well as
fire weather concerns.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Monday Night)
Issued At 1050 PM MDT Sun Sep 29 2024

Gusty southerly surface winds will continue through evening,
especially over KRAP and the western SD plains. A frontal passage
overnight will shift winds out of the northwest after 06-08z
tonight; gusty northwesterly winds will continue through Monday.
Gusts 30 to 50 mph are possible; strongest from KRAP to KRCA.

&&

.FIRE WEATHER...
Issued At 1258 AM MDT Mon Sep 30 2024

A strong cold front will move through the region today,
supporting wind gusts over 50 mph most areas this morning. Very
dry air behind the front will allow RH down below 20 percent most
areas today. Hence, will continue the red flag warning. Most days
this week will see near critical to critical fire weather
conds. Critical fire weather conds expected again Tues as southerly
return flow behind departing high pressure will support wind
gusts of 25 to 35 mph over most of the area. Very dry air will
remain in place supporting widespread RH down below 15 percent in
the afternoon. Hence, a red flag warning is anticipated for Tues
as well most areas. Above normal temps, breezy weather, and very
dry conds will continue most of the week.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Warning until noon MDT today for SDZ001-012-031-072-
     073.
     Red Flag Warning until 8 PM MDT /9 PM CDT/ this evening for
     SDZ319>335.
     Wind Advisory until noon MDT /1 PM CDT/ today for SDZ002-013-014-
     025-026-030-032-041>044-046-047-049-075>078.
WY...Red Flag Warning until 8 PM MDT this evening for WYZ314>318.
&&

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...SE
FIRE WEATHER...JC