Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
203 PM EDT Wed Oct 28 2026

Valid 00Z Thu Oct 29 2026 - 00Z Sat Oct 31 2026

...Heavy rainfall and flash flooding threats to expand across the Southern
High Plains and Southwest through Friday...

...A progressive cold front will bring showers and thunderstorms from the
Mississippi Valley to parts of the Northeast...

...Accumulating mountain snow in the Cascades and Northern Rockies while
unseasonable warmth dominates the East...

A multi-day heavy rainfall and flash flooding threat will unfold across
portions of the Southern High Plains and Southwest through the end of the
week. An upper-level trough anchored over the Western U.S. will allow for
favorable large-scale ascent across the southern tier, while a
southern-stream jet streak provides divergence aloft. Concurrently, a
southerly low-level jet will bring abundant moisture from the Gulf,
driving high precipitable water across western Texas. Favorable lift and a
concomitant influx of deep moisture will support widespread showers and
thunderstorms across West and Central Texas into the Southern High Plains
on Thursday. Convective rain rates reaching 1.5 to 2.5 inches per hour
will be capable of producing localized to scattered flash flooding,
particularly across urban drainages, low-lying areas, and sensitive
terrain. As such, there is a high-end Slight Risk (level 2/4) of excessive
rainfall across portions of West and Central Texas on Thursday, with a
Marginal Risk (level 1/4) extending into southern New Mexico. By Friday, a
secondary surge of moisture originating from the Gulf of California will
overspread the Desert Southwest ahead of the advancing upper trough. Heavy
showers and thunderstorms will focus across central and southern Arizona,
where terrain-induced lift and saturated soils will heighten runoff
potential. Consequently, a Slight Risk (level 2/4) of excessive rainfall
is in effect for central and southern Arizona on Friday, where repeated
rounds of rainfall will carry a risk of scattered flash flooding across
steep terrain, narrow canyons, and recent burn scars.

Farther north and east, an advancing surface cold front will progress
across the eastern half of the nation from Thursday into Friday. Supported
by a mid-level shortwave trough tracking along the international border,
the front will push across the Mid-Mississippi Valley and Central Plains
early Thursday morning before entering the Great Lakes and Ohio Valley
Thursday afternoon. The cold front will then press into the Lower Great
Lakes and interior Northeast by Thursday evening. The boundary will
gradually decelerate as it approaches the Atlantic coast by Friday night,
maintaining scattered showers along coastal sectors while high pressure
building across the northern midsection ushers in a noticeably drier air
mass.

Across the Northwest, persistent onshore flow associated with a
slow-moving surface frontal system will bring widespread precipitation
into the Pacific Northwest, Northern Great Basin, and Northern Rockies
through Friday. Accumulating snow is expected across the higher elevations
of the Washington and Oregon Cascades, where several inches of wet snow
will create slick travel over mountain passes. High-elevation snow and a
wintry mix will also extend into portions of the Northern Rockies.

In terms of temperatures, an amplified upper-level ridge positioned along
the East Coast will bring unseasonable warmth, driving afternoon highs 10
to 20 degrees above seasonal averages. Highs in the 70s and lower 80s are
expected from the Ohio Valley through the Mid-Atlantic and Southeast. In
sharp contrast, a Canadian air mass settling behind the departing cold
front will hold daytime maximums in the 40s and 50s across the Northern
Plains and Upper Midwest. Meanwhile, extensive cloud cover and
precipitation will suppress daytime temperatures across the Great Basin
and Southwest, keeping conditions well below late October averages.


Blanco-Alcala


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx...

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