Fireblight infection conditions - MaryBlyt model logic

Background Information for this page
Return to radar list for Middletown RI
Weather data for Middletown RI.  Forecast values begin August 3, 2010
Shoots near overwintered fireblight cankers would start showing obvious symptoms around  Sunday, June 06
 If canker blight infection spreads to other shoots,
symptoms on those shoots would become obvious around Saturday, June 19
   If fire blight blossom infection occurred on May 26, then blossom blight would be noticeable by June 6, and shoot blight by June 18.
Range of potential
open-blossom dates
Gray box indicates dates when most trees will have lost open blossoms and susceptibility to blossom infection, but late blooming cultivars or young trees may still be susceptible.
Inches Rain,
Leaf Wet Hours,
DH65 heat units, &
Avg. Temperature
Daily fireblight risk rating
as per Maryblyt model criteria
by Dr. Paul Steiner and Gary Lightner. 

In absence of rain, 3 or more hours of leaf wetness counted as possible dew conditions for adequate wetting, which may overstate risk on such days.
Infection requirements:
Any rain, or >0.1 inch rain on previous day,
+ 198 cumulative degree hours > 65F,
+ Average temp. on wetting day >= 60F
Mac King Bloom
Sat, April 24 
  0.'',  0 hrs.,  0 DH,  54F No FB infection
Sun, April 25    0.13'',  16 hrs.,  0 DH,  50F No FB infection
Mon, April 26    0.3'',  21 hrs.,  0 DH,  51F No FB infection
Tue, April 27    0.19'',  24 hrs.,  0 DH,  47F No FB infection
Wed, April 28    0.'',  5 hrs.,  0 DH,  44F No FB infection
Thu, April 29    0.'',  0 hrs.,  0 DH,  52F No FB infection
Fri, April 30    0.'',  0 hrs.,  39 DH,  60F No FB infection
Sat, May 1    0.'',  0 hrs.,  66 DH,  62F No FB infection
Sun, May 2    0.'',  9 hrs.,  44 DH,  59F No FB infection
Mon, May 3    0.31'',  18 hrs.,  75 DH,  64F No FB infection
Tue, May 4    0.05'',  8 hrs.,  124 DH,  65F No FB infection
Wed, May 5    0.'',  1 hrs.,  142 DH,  64F No FB infection
Thu, May 6    0.'',  12 hrs.,  146 DH,  60F No FB infection
Fri, May 7    0.'',  0 hrs.,  119 DH,  58F No FB infection
Sat, May 8    0.6'',  21 hrs.,  80 DH,  57F No FB infection
Sun, May 9    0.'',  0 hrs.,  60 DH,  49F No FB infection
Mon, May 10    0.'',  0 hrs.,  0 DH,  49F No FB infection
Tue, May 11    0.'',  0 hrs.,  0 DH,  48F No FB infection
Wed, May 12    0.'',  0 hrs.,  0 DH,  47F No FB infection
Thu, May 13    0.'',  6 hrs.,  0 DH,  51F No FB infection
Fri, May 14    0.17'',  22 hrs.,  0 DH,  54F No FB infection
Sat, May 15    0.1'',  8 hrs.,  36 DH,  63F No FB infection
Sun, May 16    0.'',  0 hrs.,  38 DH,  58F No FB infection
Mon, May 17    0.'',  0 hrs.,  70 DH,  58F No FB infection
Tue, May 18    1.'',  16 hrs.,  47 DH,  52F No FB infection
Wed, May 19    0.39'',  24 hrs.,  35 DH,  55F No FB infection
Thu, May 20    0.'',  11 hrs.,  58 DH,  62F No FB infection
Fri, May 21    0.'',  0 hrs.,  141 DH,  65F No FB infection
Sat, May 22    0.'',  4 hrs.,  73 DH,  58F No FB infection
Sun, May 23    0.'',  18 hrs.,  98 DH,  63F No FB infection
Mon, May 24    0.'',  12 hrs.,  152 DH,  64F No FB infection
Tue, May 25    0.'',  10 hrs.,  151 DH,  66F No FB infection
Wed, May 26    0.05'',  1 hrs.,  330 DH,  73F INFECTION RISK
Thu, May 27    0.21'',  12 hrs.,  287 DH,  61F INFECTION RISK
Fri, May 28    0.'',  0 hrs.,  300 DH,  61F INFECTION RISK
Sat, May 29    0.17'',  7 hrs.,  240 DH,  61F INFECTION RISK
Sun, May 30    0.'',  10 hrs.,  188 DH,  70F No FB infection
Mon, May 31    0.'',  0 hrs.,  220 DH,  65F No FB infection
Tue, June 1    0.29'',  20 hrs.,  238 DH,  66F INFECTION RISK
Wed, June 2    0.'',  18 hrs.,  292 DH,  65F INFECTION RISK