Discussion: NOAA issues new long-lead forecasts this morning. NOAA highlights include a less warm trend for Central U.S. for summer and increased chance of El Nino influence beginning with the autumn forecast. Climate Impact commentary follows.
MAY 2018: The outlook favors warmth everywhere except Northwest U.S. The outlook is wet in the East. CIC is colder in the North and agrees with NOAA on a wet eastern regime for May favoring a more temperate climate (East) vs. NOAA.
Fig. 1-2: May 2018 temperature and precipitation probability forecast from NOAA.
JUN/JUL/AUG 2018: The outlook remains warm West, Southwest, Gulf Region and East. The warmth is based on an upper ridge presence northeast of warm SSTA in the southeast North Pacific and just west and northwest of warm SSTA in the western North Atlantic. In-between an upper trough is likely. The previous Northeast wet anomaly is a little larger and Florida and New Mexico are wetter. Equal chance of dry, wet or normal in the Great Plains while dryness shifts into the Northwest.
Fig. 3-4: JUN/JUL/AUG 2018 temperature and precipitation probability forecast from NOAA.
SEP/OCT/NOV 2018: The outlook indicates warm risk everywhere based on NMME, CFS V2 and GFDL consensus. These models are biased toward warmth due to their very warm global ocean SSTA forecasts. The precipitation forecast is issued with no skill.
Fig. 5-6: SEP/OCT/NOV 2018 temperature and precipitation probability forecast from NOAA.
DEC/JAN/FEB 2018-19: Weak El Nino is possible. The outlook is warm in the Southwest U.S. and Northeast States. The precipitation forecast indicates no skill.
Fig. 7-8: DEC/JAN/FEB 2018-19 temperature and precipitation probability forecast from NOAA.