Things are coming into a bit better perspective now in regard to this upcoming weeks weather pattern. Through Tuesday we will remain under the influence of high pressure and we will have dry, sunny days and clear nights. With increasing moisture ahead of our next weather system, it will be warmer at night than what it has been. By Tuesday night, the main storm system will be approaching the state. An active Halloween is in store for the natural state as a cold front moves through the state and an upper low pressure develops over the four corners and moves just behind the front. Rainfall will be the biggest story on Halloween with most of the rainfall being post frontal. A general one to three inches is expected.
Severe threat is rather limited with this system. While a system of this strength would normally produce severe weather, there are limiting factors involved. Instability is the main issue with little if any fuel to sustain super cellular development. Shear is moderate so cannot rule out a few stronger storms with damaging winds the main threat. Another factor is how fast does the front move? If the front undercuts the leading edge of any developing thunderstorms then that limits severe threat as well. Also temps will be marginal with quickly falling temps post frontal. The greatest chance of anything isolated severe would be over the southeastern part of the state, which is where I had highlighted. Overall though, severe threat just looks rather non existent at this point. Future data will determine how things will shape up. Usually highly amplified patterns tend to keep Arkansas out of the severe threat and keeps it east of the state, which is exactly what current guidance and atmospheric profiles have advertised.
Biggest issue is timing. GFS is wanting to move the rainfall out early Thursday morning with the EURO wanting to keep wrap around moisture in place, keeping rain over the state through Thursday night. With the discrepancy only around 12 hours difference, have gone with a blend of this and decrease rainfall by mid day. Only left low end pops for now to account for uncertainty, but we could see Thursday go up in subsequent outlooks.
So overall Wednesday does look unsettled and not quite a washout. Rain chances could come up a bit more as well an max out in future outlooks.
Temps will be above normal through the period.
Period will begin with departing upper low and cold front to our south and east. Dry weather will be seen for Friday as the system pulls away and drier air works in. Things get a bit more uncertain for Friday night however as the GFS wants to develop a closed low over the state with a backdoor cold front moving through the state. This solution would have ample amount of forcing to produce precipitation over the state, but the question is will moisture return be significant enough between the two systems. The EURO is much weaker with aforementioned system with little if any moisture in place. Have opted to keep precip chances below 20 percent with this outlook due to the uncertainty of the moisture return but will monitor for future outlooks for Friday night and early Saturday. Any precip that would fall would be of the liquid variety as the lowest levels of the atmosphere would be to warm for anything frozen. If this was winter, that could be a different story. Beyond this, sunshine returns for the weekend.
As I expected, freeze potential has been removed from the forecast. With a lack of snow pack to our north, temps will modify greatly before reaching us. Patchy frost will be possible in the north but overall not expecting anything to bad with 50s and 60s for highs and 30s and 40s for lows.
Temps will be at to below average through the period.