Valid Thursday April 30, 2015 to Monday May 11, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT April 27 2015Synopsis
: At the beginning of the outlook
period, a low-pressure system is forecast over the Carolina Coast, with a
projected northeastward track. After that system moves out, high pressure is
forecast over much of the lower 48 states for the ensuing 2-3 days. A weak low
pressure system is forecast to develop over the northern Great Plains early
next week. Through early next week, most of Alaska is likely to experience
seasonable weather as low-pressure near the Aleutians is not expected to be
particularly intense. Forecasts for next week indicate a more active pattern
across the Southwest and Great Plains. Hazards
Detailed Summary For Thursday April
30 - Monday May 04:
rain for the southern mid-Atlantic, Thu, Apr 30.
- Flooding likely along the Guadalupe River at Bloomington, Thu, Apr 30.
- Flooding occurring or imminent for parts of the Souris River in North
Dakota due to water release from Lake Darling.
- Severe drought for the central and southern Great Plains, Southwest, Great
Basin, California, the Pacific Northwest, southern Florida, and Hawaii.
A moderate strength low-pressure system is forecast to
be over the Carolinas at the start of the outlook period. Heavy rains (1-2
inches) are likely along and just north of the track of the low-pressure
system. GFS-based forecasts are slower in propagating the low-pressure system,
and accordingly produce more rains from the DelMarVa to the Carolinas. If the
low pressure system tracks closer to the coast, rains could extend into the
weekend across portions of the northeast. Additionally, with a more westward
track, high winds and coastal flooding become more likely for New England and
portions of Long Island.
Flooding is likely over Southeast Texas, along the Guadalupe River. Recent
heavy rains have dramatically increased runoff. Flooding in central Mississippi
is likely to abate before the outlook period, but any rain between now the
start of the valid period would likely exacerbate and prolong the flooding.
A low-pressure system is forecast develop over the northern Great Plains by
the beginning of next week. As the system deepens, winds are likely to approach
critical fire weather thresholds, but uncertainty in the relative humidity
values and wind speeds preclude the designation of a hazard at this
For Tuesday May 05 - Monday May 11:
The overall pattern for next week is
likely to feature a trough near the Aleutians and a trough over the western
half of the CONUS, with ridging from the Great Plains to the east coast. That
pattern favors above median rains for much of the lower 48 states. Mean
troughing favors above median precipitation for southern Alaska.
Early next week, some models are indicating a shortwave trough moving
through the pattern over the Southwest. A shortwave moving through the
southwest would increase the threat for severe weather over the southern and
central Great Plains, as well as increasing the threat of heavy rains over the
The most recent U.S. Drought Monitor, valid on April 21, indicates a very
slight decrease (to 18.97 from 19.14 ) in the percentage of the CONUS in severe
to exceptional drought (D2-D4).
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.