Highlight: Losing the April chill once into May.
Day 1-5 Outlook (April 22-26, 2018): Wet South and East.
- Storm, Mid-South/SE U.S. rainstorm today/tonight (1-2 in. of rain) shifts to Carolinas Monday (3+ in. near Asheville/SC coast).
- Mid-Atlantic rains TUE; wet New England by WED/THU.
- Another storm develops MT/WY tomorrow to western Plains TUE and Texas/southern Plains WED/THU.
- Temperate…the bitter cold of early spring departs the pattern.
Day 6 to 10 Outlook (April 27-May 1, 2018): Cool start, warm finish.
- Texas rains early period shift east along Gulf Coast.
- To the north the trend is drier lead by ECMWF model.
- Cool East-Central/South early period, much warmer day 9/10.
- Very cold East-Central/South Canada early period.
- West is warm, some of that warmth eastward late in period.
- Models vary widely on precipitation amount, but prefer drier solution.
Day 11-15 Outlook (May 2-6, 2018): Wet weather Central U.S.
- Models vary on temperature…GFS is very warm (again) whereas ECMWF prefers early-to-late spring persistence.
- Using a consensus approach but trend is milder.
- Rain risk in Texas/Louisiana and Northwest but this consensus forecast may be too wet.
Focus 1: Short-term Heavy Rains Southeast.
- Strengthening low pressure system moving toward Memphis spawns heavy rain across the Southeast States today heaviest Tennessee/Alabama/Georgia.
- Storms slows down over the Carolinas tomorrow when several in. could occur along coast and southwest Appalachians.
- Expects some flooding but limited thunderstorm activity.
Focus 2: Days 8-14 U.S. Precipitation.
- Day 8-14 precipitation forecasts vary.
- Important due to influence on national soil moisture regime.
- GFS is wet and ECM is dry.
- Lack of MJO involvement favors the drier solution.
- Drier solution may also bias national climate warmer.
Climate signals: MJO change days 11-15.
- POTENTIAL for MJO phase_8 in 10+ days.
- ECMWF indicates this risk.
- If so, warmer/drier pattern in the Midwest U.S.