ATTENTION: For more information on the addition of the experimental Rapid Onset Drought hazard type to the Climate Prediction Center's 8-14 Day Hazards Outlook (Contiguous U.S. and Alaska), please click HERE.
Experimental Probabilistic Outlooks
Valid Thursday October 06, 2022 to Wednesday October 12, 2022
US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM
EDT September 28 2022
Synopsis: Mid-level high pressure during
the week-2 period is anticipated to promote drier-than-normal and unseasonably
warm conditions for much of the Contiguous U.S. (CONUS). However, flooding
remains a possibility for central Florida after copious rainfall amounts to be
received during the passage of Hurricane Ian in the coming days which would
result in saturated grounds and potential lingering floodwaters where any
additional rainfall would exacerbate conditions on the ground. Meanwhile,
dynamic models favor an active pattern for the Alaska region, leading to
periods of potentially hazardous wind and rain for much of the forecast period.
Slight risk for high winds for portions of
western Coastal Alaska, Thu-Sun, Oct 6-9.
Slight risk for heavy precipitation for portions of Interior Alaska,
Thu-Tue, Oct 6-11.
Rapid onset drought is possible for portions of the Middle Mississippi
For Thursday October 06 -
Wednesday October 12: There is good agreement among dynamic models
regarding the synoptic pattern in today’s 500-hPa height anomaly solutions,
beginning the week-2 period with mid-level ridging over the western CONUS and
weak troughing over the Great Lakes region, with this troughing diminishing by
the end of the forecast period. These conditions favor drier and warmer
conditions across much of the CONUS. Although both the ECMWF and GEFS
reforecast tools give at a least 20% probability of maximum temperatures across
much of the lower 48 exceeding the 85th percentile for much of the week-2
period, there is little chance of these temperatures reaching excessive heat
thresholds, so no hazards are posted at this time.
There is multi-model depiction of periods of weak mid-level troughing off
the West Coast and increased available moisture from the tropical Eastern
Pacific resulting in episodic rain favored for the western CONUS during the
week-2 time frame. The ECMWF reforecast tool is very bullish, with at least a
20% probability of 3-day accumulated rainfall exceeding the 85% percentile and
at least one inch total for the Four Corners region. However, this anomalous
wet signal is not supported by other guidance, including raw ECMWF output, thus
a related hazard is not posted at this time. Farther east, heavy rainfall from
the remnants of Hurricane Ian are anticipated to have moved offshore by the
week-2 period. However, very large rainfall totals are anticipated from Ian,
leaving saturated grounds and conditions ripe for additional flooding as a
result of any additional rainfall. Therefore, the outlook highlights the
potential for flooding for much of Florida.
Dry and warm conditions are favored across the central CONUS during the
week-2 period. When paired with a lack of antecedent rainfall, drought
conditions for the region are likely to develop or worsen, therefore the
potential for rapid-onset drought for central and southern Missouri is
highlighted in today’s outlook.
For the Alaska region, the week-2 period is anticipated to be characterized
by stormy conditions. Early in the period mid-level high pressure over the
Bering Sea and troughing over the Arctic Ocean is expected to lead to a tight
pressure gradient at the surface and aloft, resulting in periods of wind and
rain. The pressure gradient and surface wind is forecast to ease by the middle
of the period, although model solutions favor continuing periods of enhanced
precipitation for most of the rest of the forecast period, with probabilities
of at least 20% for exceeding 1” of rain in a 3-day period. Given these
conditions a slight risk for high winds for Oct. 6-9 is posted for portions of
the western coast of Alaska and a slight risk of heavy precipitation is
highlighted Oct. 9-11 for portions of Interior Alaska.
Forecaster: Danny Barandiaran
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.