Early stages of a blocky slow to change pattern across the U.S. developing late last present weekend prompted substantial model shifts in May forecasts. Forecast changes begin late this workweek (May 8-9) in both the Northeast (cooler) and West (hotter) after a pair wet and cool closed lows over the Ohio Valley and Southwest exit […]
Cold weekend ahead in the Midwest but computer models are latching onto only brief near seasonal cooling in the South and East followed by fast return of above average warmth to predominate the rest of October and early November.
Winter-like cold air emanating from northern Canada is on the move through the northern Rockies and northern Plains, while weakening substantially as it spreads into the summer-like warm and humid air-mass lingering in the South and East. longer range models are latching onto another strong and extended cooling event across the eastern half of the […]
Early stages of a blocky slow to change pattern across the U.S. developing late last present weekend prompted substantial model shifts in May forecasts. Forecast changes begin late this workweek (May 8-9) in both the Northeast (cooler) and West (hotter) after a pair wet and cool closed lows over the Ohio Valley and Southwest exit off the East Coast and weaken over the Southeast respectively. Instead of expanding a summerlike ridge currently sandwiched in between over the northern Plains and Upper Midwest eastward into the Northeast as most models forecast last week, all latest runs retrograde the core of unseasonably strong ridging westward generating several consecutive days of the hottest temperatures of the year (mid 100s) across the Southwest (11°-15° above average) into the middle of the 2nd full week of May. In response to increased pattern amplitude models converged to colder downstream solutions as an unseasonably cold Canadian closed low settles directly into the Northeast cooling temperatures 10°-15° below average into next weekend (May 10-11), while widespread rain-cooled conditions focus across he Southeast . Longer range forecasts valid the 11-15 day period are less aligned but deterministic models which recently performed best limit magnitude and duration of seasonably warm air reaching the Northeast early in the period ahead of yet another multiday cold air outbreak going into the 3rd full week of the month (May 18-19). Repetitive cool Canadian air reinforcement into the Northeast through late spring along with wetter forecasts across the Southeast set the stage for a relatively mild start to June across the majority of the Midwest and East (seasonal – slightly above average). In contrast expansive drought currently stretching from the Southwest to the northern-central Plains is unlikely to fully erode adding confidence to a hot start to summer across most of the western half of the U.S.
